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Hummingbird health: Pathogens and disease conditions in the family Trochilidae
Abstract
The hummingbird family (Trochilidae) is species rich; however the effects of infectious agents and diseases on these birds have received little attention. We compiled and summarized published findings describing disease conditions in hummingbirds in order to provide a comprehensive overview of existing data to assist management and conservation of captive and free-ranging hummingbird populations. Few pathogens and disease syndromes have been described. There is a lack of information on clinical signs, pathology and epidemiology and their variation across species for most disease syndromes. Consequently, there is not enough information to determine the impact of diseases in hummingbird populations, including those of conservation concern. Several physiological, behavioral and ecological characteristics render hummingbirds as an interesting species for the study of wildlife disease ecology. Additionally, feeding ecology with prodigious diets of insects and nectar support consideration as "environmental samplers"; hummingbirds will serve as potential sentinels for assessing the environmental impacts of pollutants and pesticides. We conclude that further studies are needed to better understand the role of diseases in hummingbird fitness and survival. In this sense, hummingbird health monitoring programs are fundamental to securing scientific information on normal and abnormal health parameters.
... Habitat loss and degradation appear to contribute broadly to declines in hummingbird populations, although the impacts of other stressors have not been well studied (Wethington and Finley, 2009). Infectious agents and diseases are known to play a large role in avian population declines, although little is known about how they affect hummingbirds specifically (Godoy et al., 2014). ...
... Hummingbirds are prone to exposure to a wide range of pathogens and diseases (Magagna et al., 2019), including avian pox virus (Godoy et al., 2013;Baek et al., 2020), West Nile virus (Backus et al., 2019), Chlamydia spp., Salmonella spp., Aspergillus spp., numerous helminth infections, various mites (Yamasaki et al., 2018), lice, ticks, and several species of protozoan blood parasites, including haemosporidians (Godoy et al., 2014;Bradshaw et al., 2017;Magagna et al., 2019). Haemosporidians are of significance because of their high diversity across the avian tree of life, with over 250 species of haemosporidian blood parasites infecting a wide variety of avian hosts (Valki unas et al., 2004). ...
... It appears that haemosporidian prevalence within hummingbirds is highly dependent on species, and it remains unclear why certain species harbor higher parasite loads. Multiple factors could possibly be influencing this pattern, including host competency, vector specificity, and/or possible inconsistencies in sampling or detection methods (Godoy et al., 2014). ...
Hummingbirds are vital members of terrestrial ecosystems, and because of their high metabolic requirements, they serve as indicators of ecosystem health. Monitoring the parasitic infections of hummingbirds is thus especially important. Haemosporidians, a widespread group of avian blood parasites, are known to infect hummingbirds, but little is known about the prevalence and diversity of these parasites in hummingbirds. The prevalence of haemosporidians in several hummingbird species was examined and we compared 4 different tissue types in detecting parasites by polymerase chain reaction (PCR). Blood samples from 339 individuals of 3 different hummingbird species were tested, and 4 individuals were found positive for haemosporidian infection, a prevalence of 1.2%. Hummingbird carcasses (n = 70) from 5 different hummingbird species were also sampled to assess differences in detection success of haemosporidians in heart, kidney, liver, and pectoral muscle tissue samples. Detection success was similar among tissue types, with haemosporidian prevalence of 9.96% in heart tissue, 9.52% in kidney tissue, 10.76% in liver tissue, and 11.76% in pectoral muscle tissue. All tissue samples positive for haemosporidian infection were from the Black-chinned Hummingbird (Archilochus alexandri). Possible reasons for low prevalence of these blood parasites could include low susceptibility to insect vectors or parasite incompatibility in these hummingbirds.
... Hummingbirds are birds of the family Trochilidae, which is endemic to the American continents and can be parasitized by both Plasmodium and Haemoproteus. However, to date, hummingbirds have not been well studied with regard to avian malaria [4,14]. Therefore, we investigated avian malaria in premontane forests, which harbor a great abundance and diversity of hummingbirds [15]. ...
... F=Female, M=Male, and Unk=Unknown Available at www.veterinaryworld.org/Vol.14/April-2021/12.pdf avian malaria [4,14], and our work is the first report on malaria in hummingbirds from Northwest Ecuador. The scant literature suggests that Haemoproteus infections are higher in hummingbirds than in passerine birds [4,10,40,41], with the first studies reporting pathologies similar to malaria in hummingbirds 70 years ago, and those confirming avian malaria in Trochilidae as recent as 15 years ago [14,42]. ...
... avian malaria [4,14], and our work is the first report on malaria in hummingbirds from Northwest Ecuador. The scant literature suggests that Haemoproteus infections are higher in hummingbirds than in passerine birds [4,10,40,41], with the first studies reporting pathologies similar to malaria in hummingbirds 70 years ago, and those confirming avian malaria in Trochilidae as recent as 15 years ago [14,42]. Some of the existing studies concerning Haemoproteus infections in hummingbirds include Bradshaw and collaborators, who studied the presence and prevalence of Haemoproteus archilochus in two species of California hummingbirds, Archilochus alexandri and Calypte anna. ...
As a nonlethal disease, avian malaria can affect the lifespan and reproductive rate of birds. If there is a differential effect
depending on bird species, then this disease might have a significant effect on avian biodiversity. The current study aimed
to determine the incidence of Plasmodium in hummingbirds in humid premontane forest areas.
Materials and Methods: Blood samples (n=60) were collected from hummingbirds from two areas (Santuario de Aves Milpe
and Hacienda Puyucunapi) of Pichincha Province, Ecuador. Prevalence and parasitemia were determined by microscopic
examination of blood smears stained with Giemsa reagent. Both study sites are part of a 1000 m elevational gradient; hence,
elevation was used as a predictor variable for prevalence and parasitemia levels in a Mann–Whitney U-test. This test was
also used to test for a sex bias.
Results: This study reports on a total of 12 bird species that inhabit both study sites. At Milpe, the lower elevation site, a
prevalence of 100% was recorded, whereas at Puyucunapi, the prevalence was 96%. The combined prevalence was 97%.
Elevation and sex did not influence prevalence nor parasitemia in hummingbirds.
Conclusion: This study does not suggest a significant elevation or sex bias on prevalence and parasitemia in hummingbirds.
Keywords: avian malaria, humid forest, hummingbirds, Pichincha, Plasmodium.
... Across the Americas, hummingbirds provide vital ecosystem services, including insectivory and pollination, and were worshipped in belief systems of diverse societies ranging from the Aztecs to the Caribbean Taino (Buzato et al. 2000;Burton 2001;Yanega and Rubega 2004). Hummingbirds are also valuable sentinel species as landscape level Bsamplers^as changes in their health can be indicative of underlying environmental changes and overall ecosystem health (Godoy et al. 2014). Four of the seven hummingbird species that regularly breed in California are classified by the National Audubon Society as Bspecies of conservation concern^(Audubon. ...
... org). Potential risks to hummingbird populations include infectious diseases, habitat degradation, climate change, and invasive species (Godoy et al. 2014). Though chronic infections with haemoparasites were often thought to be relatively harmless, they have been experimentally demonstrated to be pathogenic in wild birds, and potential impacts on hosts vary among blood parasite species (Earlé et al. 1993;Merino et al. 2000;Marzal et al. 2005;Olias et al. 2011;Asghar et al. 2015). ...
... The pathogenicity of the detected H. archilochus infections on hummingbird hosts is not known. Though sampled hummingbirds were considered to be healthy based on field-based physical examinations, the possibility that chronic Haemosporidian infection can be recurrent or cause subtle health effects with a deleterious impact on fitness cannot be ruled out (Merino et al. 2000;Martínez-de la Puente et al. 2010;Godoy et al. 2014;Asghar et al. 2015). With a rapidly changing global climate and anthropogenic alterations of these species' natural habitats, infectious disease risks are likely to be above historic levels and can be expected to potentially increase even further (Aguirre and Tabor 2008). ...
Haemosporidian blood parasites are transmitted to a wide range of avian hosts via blood-sucking dipteran vectors. Microscopy has revealed an impressive diversity of avian haemosporidia with more than 250 species described. Moreover, PCR and subsequent sequence analyses have suggested a much greater diversity of haemosporidia than morphological analyses alone. Given the importance of these parasites, very few studies have focused on the charismatic hummingbirds. To date, three Haemoproteus species (Haemoproteus archilochus, Haemoproteus trochili, and Haemoproteus witti) and one Leucocytozoon species (Leucocytozoon quynzae) have been described in blood samples taken from hummingbirds (Trochilidae). Unconfirmed Plasmodium lineages have also been detected in hummingbirds. Here, we report the detection of H. archilochus in two hummingbird species (Calypte anna and Archilochus alexandri) sampled in Northern California and perform a phylogenetic analysis of mitochondrial cytochrome b (cyt b) gene lineages. A total of 261 hummingbirds (157 C. anna, 104 A. alexandri) were sampled and screened for blood parasites using PCR and microscopy techniques. Combining both methods, 4 (2.55%) haemosporidian infections were detected in C. anna and 18 (17.31%) haemosporidian infections were detected in A. alexandri. Molecular analyses revealed four distinct H. archilocus cyt b lineages, which clustered as a monophyletic clade. No species of Plasmodium or Leucocytozoon were detected in this study, raising the possibility of specific vector associations with hummingbirds. These results provide resources for future studies of haemosporidian prevalence, diversity, and pathogenicity in California hummingbird populations.
... Wild hummingbirds are not commonly presented for veterinary care, probably because of their small size and unlikeness of being found injured, and also because injuries are likely quickly fatal being highly active foragers and vulnerable prey species. General disease prevalence in free-living hummingbirds is infrequently reported (0.1%, Godoy et al. 2014), with the most common physical abnormalities being related to avian poxvirus and trauma (Godoy et al. 2014;Colwell 2011;Godoy et al. 2013), both of which have been reported to affect the eyes . Mites and other external parasites are commonly detected in hummingbird populations, and although are typically benign they can have ocular consequences (Russell 2012). ...
... Wild hummingbirds are not commonly presented for veterinary care, probably because of their small size and unlikeness of being found injured, and also because injuries are likely quickly fatal being highly active foragers and vulnerable prey species. General disease prevalence in free-living hummingbirds is infrequently reported (0.1%, Godoy et al. 2014), with the most common physical abnormalities being related to avian poxvirus and trauma (Godoy et al. 2014;Colwell 2011;Godoy et al. 2013), both of which have been reported to affect the eyes . Mites and other external parasites are commonly detected in hummingbird populations, and although are typically benign they can have ocular consequences (Russell 2012). ...
The phylogenetic crown-group Strisores is a diverse group of birds consisting of about 570 species across 8 families. Phylogenetic classification is controversial based on morphologic and genetic evidence, but overall families and orders consistently considered include Caprimulgidae (nightjars and nighthawks), Steatornithidae (oilbird), Nyctibiidae (Potoos), Podarigdae (frogmouths), and Aegothelidae (owlet-nightjars), all of which are commonly classified as the order Caprimulgiformes, and the Adpodidae and Hemiprocnidae (swifts and treeswifts) and Trochilidae (hummingbirds), together creating the order Apodiformes. Given similar visual ecology, ocular anatomy, and ophthalmic conditions of the Caprimulgiformes, Hemiprocnidae, and Apodidae, the respective families will be discussed together, with key differences noted were relevant. The Trochilidae will be discussed separately considering their unique visual and ecological attributes.
... 83,84 Several characteristics render hummingbirds as an interesting species for the study of wildlife disease ecology experimentally. 85 They are known to carry Encephalitozoon hellem that causes keratoconjunctivitis, sinusitis, and, uncommonly, systemic disease in humans. 85,86 Similarly, sandgrouse (Pterocles spp.), which are important model animals for understanding dessert dwellers, drink by soaking up water by specialized belly feathers. ...
... 85 They are known to carry Encephalitozoon hellem that causes keratoconjunctivitis, sinusitis, and, uncommonly, systemic disease in humans. 85,86 Similarly, sandgrouse (Pterocles spp.), which are important model animals for understanding dessert dwellers, drink by soaking up water by specialized belly feathers. 87 Lastly, the timing of when water is delivered and volume of water consumed can vary seasonally. ...
Research with captive wildlife in Animal Biosafety Level 2 (ABSL2) and 3 (ABSL3) facilities is becoming increasingly necessary as emerging and re-emerging diseases involving wildlife have increasing impacts on human, animal, and environmental health. Utilizing wildlife species in a research facility often requires outside the box thinking with specialized knowledge, practices, facilities, and equipment. The USGS National Wildlife Health Center (NWHC) houses an ABSL3 facility dedicated to understanding wildlife diseases and developing tools to mitigate their impacts on animal and human health. This review presents considerations for utilizing captive wildlife for infectious disease studies, including, husbandry, animal welfare, veterinary care, and biosafety. Examples are drawn from primary literature review and collective 40-year experience of the NWHC. Working with wildlife in ABSL2 and ABSL3 facilities differs from laboratory animals in that typical laboratory housing systems, husbandry practices, and biosafety practices are not designed for work with wildlife. This requires thoughtful adaptation of standard equipment and practices, invention of customized solutions and development of appropriate enrichment plans using the natural history of the species and the microbiological characteristics of introduced and native pathogens. Ultimately, this task requires critical risk assessment, understanding of the physical and psychological needs of diverse species, creativity, innovation, and flexibility. Finally, continual reassessment and improvement are imperative in this constantly changing specialty area of infectious disease and environmental hazard research.
... The study of wild birds remains essential for ornithologists who are trying to understand, under natural conditions, basic questions of ecology, physiology, disease, and behavior. Capture, restraint, and sampling of hummingbirds have led to a better understanding of their physiology and flight mechanics Warrick et al. 2005;Bakken and Sabat 2006;), evolution of biodiversity and mutualisms González-Gómez et al. 2014a., b;Maglianesi et al. 2014a, b;Ornelas et al. 2014;Abrahamczyk and Renner 2015;Gonzalez and Loiselle 2016), disease prevalence (Godoy et al. 2013(Godoy et al. , 2014Backus et al. 2019;Magagna et al. 2019;Baek et al. 2020), and taxonomy and systematics . Much of this research has been achieved through obtaining biological samples such as blood, muscle, organ tissues, excreta, or feathers from live hummingbirds or preserved specimens. ...
... Literature review yielded 39 unique studies that demonstrated trends in organs sampled, quantities extracted, and applications (Table 9). Some of the research applications for sampling tissues include phylogenetics (Gerwin and Zink 1998;McGuire et al. 2014;Weinstein et al. 2014), epidemiology (Magagna et al. 2019), toxicology (Godoy et al. 2014;Filigenzi et al. 2019;Graves et al. 2019), and physiology (Mathieu-Costello et al. 1992). Due to their small body size and a paucity of techniques for antemortem tissue sampling, carcasses are most commonly utilized for tissue samples. ...
Research on hummingbirds over the decades has provided insights into their evolution, migration, physiology, and numerous other areas, including conservation biology. Their small size, energy demands, and high metabolic rates are some of the challenges researchers face when obtaining research samples and biologic materials from live hummingbirds. This manuscript summarizes the established literature dealing with basic methods that scientists have used when capturing, handling, and otherwise researching hummingbirds. Based on the authors’ experience, best practices for working with live hummingbirds are presented, including permitting requirements for studying live hummingbirds, trapping and marking, handling techniques, safe collection of tissue samples, first-aid measures, and euthanasia of hummingbirds, as well as processing of hummingbird specimens (e.g., necropsy and preservation).
... 83,84 Several characteristics render hummingbirds as an interesting species for the study of wildlife disease ecology experimentally. 85 They are known to carry Encephalitozoon hellem that causes keratoconjunctivitis, sinusitis, and, uncommonly, systemic disease in humans. 85,86 Similarly, sandgrouse (Pterocles spp.), which are important model animals for understanding dessert dwellers, drink by soaking up water by specialized belly feathers. ...
... 85 They are known to carry Encephalitozoon hellem that causes keratoconjunctivitis, sinusitis, and, uncommonly, systemic disease in humans. 85,86 Similarly, sandgrouse (Pterocles spp.), which are important model animals for understanding dessert dwellers, drink by soaking up water by specialized belly feathers. 87 Lastly, the timing of when water is delivered and volume of water consumed can vary seasonally. ...
Isopod parasites in the family Cymothoidae can cause reduced growth, castration, or even mortality in their hosts. Olencira praegustator is a cymothoid that parasitizes the mouth and gill chamber of Brevoortia tyrannus (Atlantic menhaden), which is the basis for the largest fishery along the eastern coast of the USA and an important link within estuarine food webs. To better characterize interactions between O. praegustator and B. tyrannus, including parasite‐induced pathology, we sampled hosts and parasites from three estuarine sites on Kiawah Island, South Carolina. Over 5 weeks, we collected, measured, and weighed 169 juvenile menhaden; remarkably, 96% of these fish were infected with O. praegustator, typically with one isopod found in the mouth of each host. Based on the external morphologies of 163 examined isopods, 58 were female (35.6%), 9 of which were gravid, and 105 were male (64.4%). Although fish size was unrelated to isopod length or mass, isopod length was a direct predictor of the amount of damage observed on the host operculum, which in severe cases involved tissue atrophy and hemorrhage. Considering the high infection prevalence, significant damage associated with infections, as well as the impairing effects of other cymothoids on their hosts, the consequences of interactions between B. tyrannus and O. praegustator warrant additional investigation for understanding the management and ecology of Atlantic menhaden.
... Avian pox can infect a wide range of bird species, including hummingbirds [4]. Hummingbirds appear to be especially vulnerable to the effects of the pox virus because of their high metabolic requirements [5]. Understanding how avian pox impacts hummingbird populations is important since these iconic pollinators can be indicators of environmental health. ...
... Understanding how avian pox impacts hummingbird populations is important since these iconic pollinators can be indicators of environmental health. As such, information about hummingbird diseases can inform us about the general health of the environments they inhabit [5]. ...
Background
Avian pox is a viral disease documented in a wide range of bird species. Disease-related detrimental effects can cause dyspnea and dysphagia, and birds with high metabolic requirements, such as hummingbirds, are thus especially vulnerable to the pathogen. Hummingbirds have a strong presence in California, especially in urban environments. However, little is understood regarding the impact of pox virus on hummingbird populations. Currently, diagnosing a pox infection relies on obtaining a tissue biopsy, which poses significant risks to birds and challenges in the field. Understanding the ecology of hummingbird pox viral infections could be advanced by a minimally invasive ante-mortem diagnostic method. Our aim was to address whether pox infections can be diagnosed using integumentary system samples besides tissue biopsies. To meet this goal, we tested multiple integumentary sample types using a quantitative real-time PCR assay. A secondary study goal was to determine which sample types (ranging from minimally to highly invasive sampling) were optimal for identifying infected birds.
Methodology and principal findings
Pox-like lesion tissue, pectoral muscle, feathers, toenail clippings, blood, and swabs (both pox-like lesion tissue and non pox-like lesion tissue) were taken from live birds and carcasses of two species of hummingbirds found in California. To maximize successful diagnosis, especially for samples with low viral load, a real-time quantitative PCR assay was developed for detecting the hummingbird-specific Avipoxvirus 4b core protein gene. Avipoxvirus DNA was successfully amplified from all sample types obtained from 27 individuals. These results were compared to those of conventional PCR and comparisons were also made among sample types, utilizing lesion tissue samples as the gold standard.
Conclusions and significance
Hummingbird avian pox can be diagnosed without relying on tissue biopsies. We identify that feather samples, of which contour feathers yielded the best results, can be used for diagnosing infected birds, thus reducing sampling risk. In sum, the real-time PCR assay detected viral DNA in various integumentary system sample types and will be useful in future studies of hummingbird disease ecology.
... To date, there is very little data on bacterial pathogens affecting hummingbirds with only four species recorded as pathogenic to hummingbirds including Chlamydia psittaci, Mycobacterium avium, Salmonella typhimurium, and Serratia marcescens [9,10]. Four species of fungi have also been recorded as pathogens of hummingbirds, including a Candida species [11]. Comparatively, there are an abundantly greater number of eukaryotic parasites identified in hummingbirds. ...
... Comparatively, there are an abundantly greater number of eukaryotic parasites identified in hummingbirds. There are currently 23 species of parasites including helminths, protozoa and ectoparasites that are known to parasitize hummingbirds [11,12]. Many of the pathogens of hummingbirds have only been reported once in the literature, demonstrating the necessity of expanding the knowledge of diseases likely to threaten hummingbird populations. ...
Hummingbirds are essential pollinators in many ecosystems, making their conservation critical. As is the case with many species, hummingbirds are now facing a variety of challenges resulting from anthropogenic changes. As populations shift and species interactions change, disease is likely to pose a significant threat. There is a basic understanding of which pathogens currently affect a variety of hummingbird species, however there is a paucity of information about their immune systems capacity to kill pathogens and what specific factors may affect immunity. The objective of this study was to gain a basic understanding of the effect of age, sex, and molt on the constitutive innate immunity of hummingbirds. An in vitro assay was used to assess the microbiocidal capacity of the whole blood of Anna’s Hummingbirds (Calypte anna) against three different microbes: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans). The effect of age, sex and molt on anti-microbial capacity varied based on the microbe type. After-hatch-year birds tended to have better anti-microbial capacity compared to hatch-year birds. Male birds had higher anti-microbial activity than female birds, although this was not observed against C. albicans. Molting birds had a weaker antimicrobial activity against E. coli and S. aureus than birds that were not molting. These results represent an important first step towards defining the parameters of constitutive innate immunity of Anna’s Hummingbirds as well as providing important knowledge about factors that should be considered when evaluating the health of wild populations.
... These birds are well adapted to both natural and urban environments and occupy a unique environmental niche as both nectivorous and insectivorous feeders. As such, they not only provide insect control and pollination services, but also function as an indicator for increased environmental pollutants such as pesticides and trace elements due to their distinctive feeding habits (Godoy et al. 2014;Mikoni et al. 2017). ...
... To our knowledge, intestinal adenovirus has not been previously reported in hummingbirds. The remainder of infectious-parasitic etiologies identified in this study have been previously reported in the literature (Godoy et al. 2013;Godoy et al. 2014;Bradshaw et al. 2017;Yamasaki et al. 2018). While previous studies have reported hemoparasitism more commonly in female birds and poxvirus selectively within Anna's Hummingbirds, the numbers of affected birds in this study was too small to draw significant statistical conclusions regarding the prevalence of these conditions between different FIGURE 2. Histologic evidence (arrows) of (A, B) a gallbladder and (C) aortic ossification for hummingbirds found in California, USA. ...
A histopathologic study of free-ranging hummingbirds in California was performed to identify mortality trends. Tissues from 61 wild hummingbirds representing five native California species collected by the San Diego Zoo from 1996 to 2016 or the Lindsay Wildlife Experience from 2015 to 2017 were histologically examined. Birds were either found dead or moribund at the time of submission or were euthanized due to unresolvable health issues. Long-term rehabilitated birds were excluded from this study. Lesions were sorted by organ, etiology, and gender. The most commonly affected organs were the lung (68%, 40/59), followed by the ingluvies (67%, 34/51) and the liver (54%, 33/61). While some birds had minimal or nonspecific lesions, 23% (14/61) had lesions primarily attributable to trauma, 16% (10/61) had lesions associated with bacteria, fungi, or viruses, 11% (7/61) had parasitic lesions, and 13% (8/61) had multifactorial concurrent processes. Infectious disease lesions included those associated with avian poxvirus, intestinal adenovirus, disseminated aspergillosis, bacterial septicemia, malaria ( Haemoproteus spp.), and mycobacteriosis. The most commonly identified parasitic infection was intestinal cestodiasis, for which there was no significant associated intestinal damage, although the large size of these cestodes may have affected digestion. The incidence of traumatic lesions did not vary significantly by sex, age, species, or sampling location. Other significant findings not related to disease or trauma, but not previously documented, were histologic evidence of a gallbladder and the presence of aortic ossification. Our study reported mortality trends at a population level for free-ranging hummingbirds in California and identified the presence of intestinal adenovirus and two anatomic structures not previously described.
... General disease prevalence in free-living hummingbirds is infrequently reported. 18 In one report of 27 000 wildcaught hummingbirds, systemic evaluation revealed an extremely low incidence of abnormalities (0.1%), with the most common physical abnormalities being proliferative lesions suspected to be related to avian poxvirus (16 individuals) and various bill injuries (11 individuals). 14 Avian poxvirus is known to result in ocular and periocular lesions and has been isolated in Anna's Hummingbirds, but its morbidity and mortality, and overall impact on migratory and stationary populations, is unknown. ...
... Intraocular pressure was measured in 362 eyes (183 birds; 140 Anna's and 43 Black-chinned Hummingbirds; Table 1). Mean AE SD (range) IOP for all birds was 11.12 AE 2.20 (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) Table 1). Mean AE SD (range) refractive error was +0.32 AE 0.33 (À0.25 to +1) D, with 82% of eyes being emmetropic (i.e. a refractive error of À0.5to +0.5 D). ...
Objective:
To estimate the prevalence of ocular disease and obtain normative ocular data for free-living hummingbirds.
Animals studied:
Two hundred and sixty-three free-living, adult Hummingbirds from coastal and inland central California were studied, including Anna's (Calypte anna, n = 186) and Black-chinned (Archilochus alexandri; n = 77) hummingbirds.
Procedures:
Slit lamp biomicroscopy and indirect ophthalmoscopy were performed on all individuals. Rebound tonometry, measurement of horizontal palpebral fissure length, and streak retinoscopy were performed on select individuals. Five conscious Anna's Hummingbirds underwent ocular imaging including fundus photography, digital slit lamp photography, and anterior segment and retinal optical coherence tomography.
Results:
The prevalence of ocular disease in this population was 2.28%. Ocular imaging revealed a thin cornea, shallow anterior chamber, large lens, and a single central, deep convexiclivate fovea. Mean ± SD intraocular pressure was 11.21 ± 2.23 mm Hg. Mean ± SD eyelid length was 2.59 ± 0.19 mm. All eyes were emmetropic or mildly hyperopic with a mean (range) ± SD refractive error of +0.32 (-0.25 to +1) ± 0.33 diopters.
Conclusions:
Consistent with previous reports, these data suggest that hummingbirds have visual characteristics found in predatory and prey species, as well as a low prevalence of spontaneous ocular disease. This work provides a set of reference values and clinical findings that can be used in the future research on hummingbird vision and ocular disease. It also provides representative diagnostic images of normal birds and demonstrates that advanced ocular imaging can be performed on manually restrained hummingbirds without pharmacologic dilation.
... A nivel del Neotrópico, Bennett y Borrero (1976), usando métodos de microscopia, lo reportaron infectando un individuo del Pico de Hoz Común (Eutoxeres aquila) muestreado en el sur occidente colombiano. La presencia de H. archilochus en diferentes regiones de Colombia, puede tener implicaciones en la conservación de las especies silvestres de colibríes, debido a que esta infección afecta el desempeño reproductivo y la supervivencia de sus hospederos (Godoy et al., 2014). ...
La infección causada por haemosporidios en colibríes no ha sido estudiada en zonas agroforestales o urbanas de la vertiente occidental de la Cordillera Oriental de los Andes en el departamento de Santander, pese a existir evidencia de esta en otros grupos de aves. Con el fin de detectar e identificar los parásitos causales de infecciones por haemosporidios, se tomaron muestras de sangre de la vena yugular de colibríes en seis localidades. La presencia de infección se llevó a cabo por PCR y la identificación de los parásitos se hizo a partir de secuencias del gen mitocondrial Citocromo b (Cyt b). Se obtuvieron 86 muestras de sangre de 20 especies de colibríes. La prevalencia de infección en general fue del 43 % y en el 18 % de las muestras infectadas del colibrí Amazilia colirufa (Amazilia tzacatl) se identificaron secuencias de Haemoproteus archilochus correspondientes al linaje HUMHA4. Se reporta por primera vez para Colombia la presencia de H. archilochus en A. tzacatl, por medio de técnicas de biología molecular. Este parásito podría estar implicado en la haemoproteosis de colibríes en el país.
ABSTRACT Haemosporidian infection in hummingbirds has not been studied in agroforestry or urban areas of the Eastern Andes' western slope, in the department of Santander, despite the existence of evidence of this in other groups of birds. To detect and identify the causative parasites of haemosporidium infections, we took blood samples from the jugular vein of hummingbirds in six locations. PCR carried out the diagnosis of the infection, and the identification of the parasites was made from sequences of the mitochondrial gene Cytochrome b (Cyt b). 86 blood samples were obtained from 20 species of hummingbirds. The prevalence of infection, in general, was 43 %, and in 18 % of the infected samples of Rufous-tailed Hummingbird (Amazilia tzacatl), sequences of HUMHA4 lineage from Haemoproteus archilochus were identified. The presence of H. archilochus in A. tzacatl is reported for the first time in Colombia using molecular biology techniques. This parasite could be implicated in the haemoproteosis of hummingbirds in the country.
... Sin embargo, si no se mantiene la higiene necesaria puede convertirse en una potencial fuente de transmisión de bacterias patógenas, debido a la fermentación de la mezcla y porque otros polinizadores, como los murciélagos y las abejas hacen uso de ellos también. Es escasa la información que se tiene de las bacterias patógenas que infectan a los colibríes, pero se han reportado algunas como Chlamydia psittaci, Mycobacterium avium, Salmonella typhimurium y Serratia marcescens que son agentes capaces de invadir su intestino ocasionando graves daños a su salud (Godoy et al., 2014) (Figura 3). ...
Introducción Los colibríes son las aves más pequeñas del mundo, se distribuyen solo en el continente americano, forman parte de la familia Trochilidae con aproximadamente 340 especies. En México se les conoce con distintos nombres como picaflores, zumbadores, pájaro mosca, chuparrosa, picaflor y chupamirto. También en algunas regiones se le llama porquesi refiriéndose a un hermoso capricho de la naturaleza, en Oaxaca se le conoce como biulú que en la lengua zapoteca significa lo que se queda en los ojos, refiriéndose a quien lo vio y no lo puede olvidar. Han tenido un gran simbolismo en nuestro país desde la época prehispánica, tanto, que su existencia está ligada a las deidades más poderosas e historia Azteca (Ibarra-García, 2009). Su alimentación se compone principalmente por el néctar que extraen de las flores con su enorme lengua, complementan su dieta con pequeños insectos para abastecer su demanda de proteína y también se ha observado que se alimentan de algunos frutos. Su función principal en los ecosistemas es ayudar a la reproducción de cientos de plantas por medio de la polinización; cuando los colibríes consumen el néctar, al momento de introducir su lengua también extraen el polen de los estambres y los transportan al estigma de otras flores dando origen a la próxima generación de plantas (Arizmendi y Berlanga, 2014). Sin embargo, para que los colibríes realicen sus funciones fisiológicas básicas, como la degradación de azúcares en su estómago, ya que ellos consumen grandes cantidades de néctar o el mantenimiento de su plumaje, que es importantes para el vuelo, búsqueda de pareja y la termorregulación, es necesaria la presencia de unas habitantes diminutas e invisibles a simple vista, llamadas bacterias, que se relacionan o interaccionan entre ellas y el hospedero para llevar a cabo funciones específicas. Estas interacciones juegan un papel crítico en la adaptación de los colibríes a su ambiente. Las bacterias son microorganismos unicelulares con una enorme diversidad de especies capaces de sobrevivir a cualquier tipo de condiciones ambientales (temperaturas altas y bajas, pH extremos). Se encuentran en diferentes ecosistemas, como en el sedimento, suelo, mar y cuerpos de agua dulce. Además, existen bacterias que cohabitan con otros organismos, en la saliva, vías respiratorias, tracto digestivo y en la L L o o s s h h a a b b i i t t a a n n t t e e s s m m i i c c r piel de los animales y humanos. Así también, las que se encuentran en diferentes partes de las plantas, como el néctar, la flor, la raíz, y las hojas. Las bacterias asociadas a organismos complejos mantienen interacciones desde parasitarias, que son capaces de producir toxinas y causar alguna enfermedad en el hospedero, hasta las mutualistas, las cuales producen compuestos antimicrobianos para eliminar otras bacterias y mantener el equilibrio en sus comunidades. Ejemplo de esto, son las bacterias que eligen como hábitat principal el intestino y el plumaje de los colibríes, los cuales están compuestos por bacterias benéficas (mutualistas) y perjudiciales (parasitarias) para ellos. Huéspedes amigables para los colibríes Las bacterias mutualistas o también llamadas microbioma del tracto digestivo de los colibríes, los ayudan a digerir alimentos y evitar el crecimiento de bacterias que puedan causarles alguna enfermedad. Así también, se ha demostrado que las comunidades bacterianas que habitan en su intestino están vinculadas con algunos procesos bioquímicos importantes para ellos. Por ejemplo, recientemente se identificaron abundantes bacterias del género Corynebacteria en el intestino de los colibríes migratorios, como el zumbador canelo (Selasphorus rufus) y el colibrí cabeza roja (Calypte anna), las cuales pueden ser capaces de descomponer compuestos que contienen nitrógeno urinario (ácido úrico, urea y urato de sodio y potasio) en su intestino. Sin embargo, aún se necesitan más estudios para comprender las funciones bioquímicas que realizan las bacterias intestinales de estas pequeñas aves (Press et al., 2003; Stanton, 2020). Las bacterias pueden alimentarse del plumaje del colibrí Se conoce bastante acerca de las bacterias que habitan en el plumaje de las aves, ya que las plumas son importantes para el vuelo, la termorregulación y la búsqueda de pareja. Estas bacterias se alimentan directamente de la pluma o, mejor dicho, de la degradación de la queratina, proteína que compone el 90% de la pluma. Es decir, Las bacterias degradan la queratina como fuente de producción de carbono y energía necesarios para realizar sus procesos
... Sin embargo, si no se mantiene la higiene necesaria puede convertirse en una potencial fuente de transmisión de bacterias patógenas, debido a la fermentación de la mezcla y porque otros polinizadores, como los murciélagos y las abejas hacen uso de ellos también. Es escasa la información que se tiene de las bacterias patógenas que infectan a los colibríes, pero se han reportado algunas como Chlamydia psittaci, Mycobacterium avium, Salmonella typhimurium y Serratia marcescens que son agentes capaces de invadir su intestino ocasionando graves daños a su salud (Godoy et al., 2014) (Figura 3). ...
Los colibríes son las aves más pequeñas del mundo,
se distribuyen solo en el continente americano, forman
parte de la familia Trochilidae con aproximadamente
340 especies. En México se les conoce con distintos
nombres como picaflores, zumbadores, pájaro mosca,
chuparrosa, picaflor y chupamirto. También en algunas
regiones se le llama porquesi refiriéndose a un hermoso
capricho de la naturaleza, en Oaxaca se le conoce
como biulú que en la lengua zapoteca significa lo que se
queda en los ojos, refiriéndose a quien lo vio y no lo
puede olvidar. Han tenido un gran simbolismo en
nuestro país desde la época prehispánica, tanto, que su
existencia está ligada a las deidades más poderosas e
historia Azteca
... Torpor reduces metabolic rate, respiration, body temperature and potentially gastrointestinal activity (McWhorter and del Rio 2000, Ruf and Geiser 2015, Shankar et al. 2020. The basis for mortality of free-ranging hummingbirds is poorly understood, but disease syndromes and exposure to environmental contaminants could be fully or partial causes (Godoy et al. 2014, Mikoni et al. 2017, Bishop et al. 2018, Magagna et al. 2019, Baek et al. 2020. Links between disease and microbial composition may lead to a better understanding of hummingbird health. ...
The gastrointestinal (GI) microbiome is an important mediator and indicator of host physiology, health and fitness in many vertebrate systems, but sources of variation in microbiome composition within species are poorly understood, particularly in free‐ranging birds. Hummingbirds have GI anatomy and physiology similar to other avian species, but they have a relatively rapid gastrointestinal transit rate, which could affect microbiome structure. To date, it has not been elucidated if microbiomes isolated from feces and samples from sections of the GI tract differ in an avian organism that has a rapid gastrointestinal time. Here, we test the hypothesis that the microbiome in free‐ranging and wildlife rehabilitation‐sourced Anna's hummingbirds Calypte anna differ between fecal and samples from three sections of the GI tract and between birds that differ in sex, age and poxvirus infection status. We characterized bacterial composition in fecal and GI tract samples from Anna's hummingbirds by amplicon sequencing of the 16S rRNA gene. We found strong evidence of differentiation in bacterial composition among GI tract regions and compared it to fecal samples. Actinobacteria, primarily genus Corynebacterium, Firmicutes and Fusobacteria were abundant in bird samples from regions of the GI tract. In contrast, fecal bacterial communities were more diverse and variable compared to GI tract samples. Bacterial community composition differed between male and female hummingbirds and with bird age (hatch year vs after‐hatch year). Finally, birds with symptoms of avian poxvirus infection had a higher relative abundance of Staphylococcus spp. than birds with no symptoms of pox. Our results suggest that Anna's hummingbirds host differentiated microbiome among GI tract regions that is consistent among individual birds. The GI bacterial community also contained taxa not represented in fecal samples. This provides evidence for the possibility of a residential gut microbiome in Anna's hummingbirds, although functional significance of the bacterial microbiome remains unknown.
... A nivel del Neotrópico, Bennett y Borrero (1976), usando métodos de microscopia, lo reportaron infectando un individuo del Pico de Hoz Común (Eutoxeres aquila) muestreado en el sur occidente colombiano. La presencia de H. archilochus en diferentes regiones de Colombia, puede tener implicaciones en la conservación de las especies silvestres de colibríes, debido a que esta infección afecta el desempeño reproductivo y la supervivencia de sus hospederos (Godoy et al., 2014). ...
La infección causada por haemosporidios en colibríes no ha sido estudiada en zonas agroforestales o urbanas de la vertiente occidental de la Cordillera Oriental de los Andes en el departamento de Santander, pese a existir evidencia de esta en otros grupos de aves. Con el fin de detectar e identificar los parásitos causales de infecciones por haemosporidios, se tomaron muestras de sangre de la vena yugular de colibríes en seis localidades. La presencia de infección se llevó a cabo por PCR y la identificación de los parásitos se hizo a partir de secuencias del gen mitocondrial Citocromo b (Cyt b). Se obtuvieron 86 muestras de sangre de 20 especies de colibríes. La prevalencia de infección en general fue del 43 % y en el 18 % de las muestras infectadas del colibrí Amazilia colirufa (Amazilia tzacatl) se identificaron secuencias de Haemoproteus archilochus correspondientes al linaje HUMHA4. Se reporta por primera vez para Colombia la presencia de H. archilochus en A. tzacatl, por medio de técnicas de biología molecular. Este parásito podría estar implicado en la haemoproteosis de colibríes en el país.
... Diseases, pesticide exposure/toxicosis (Baek et al., 2020;Bishop et al., 2018;Filigenzi et al., 2019;Godoy et al., 2013;Godoy, Tell & Ernest, 2014;Graves et al., 2019;Mikoni et al., 2017), and trauma by other wildlife species, and age all play a role in the overall success of treatment modalities. Those hummingbirds with more extensive injuries due to window collisions or being caught by a cat may be less likely to survive in general due to underlying external and internal trauma, particularly if damage to the skull or beak was sustained (Wimberger & Downs, 2010). ...
Background
Hummingbirds are frequently presented to California wildlife rehabilitation centers for medical care, accounting for approximately 5% of overall admissions. Age, sex, and reason for admission could impact hummingbird survivability, therefore identification of these factors could help maximize rehabilitation efforts.
Methods
Mixed-effects logistic regression models were used to identify specific threats to the survival of 6908 hummingbirds (1645 nestlings and 5263 non-nestlings) consisting of five species ( Calypte anna, Calypte costa, Selasphorus rufus, Selasphorus sasin, Archilochus alexandri ), found in urban settings, and admitted to California wildlife rehabilitation centers over 26 years.
Results
In total, 36% of birds survived and were transferred to flight cage facilities for further rehabilitation and/or release. Nestlings were more likely to be transferred and/or released compared to adult hummingbirds. After accounting for age, birds rescued in spring and summer were twice as likely to be released compared to birds rescued in the fall. A high number of nestlings were presented to the rehabilitation centers during spring, which coincides with the nesting season for hummingbirds in California, with the lowest number of nestlings presented in fall. Reasons for presentation to rehabilitation centers included several anthropogenic factors such as window collisions (9.6%) and interactions with domesticated animals (12.9%). Survival odds were lower if a hummingbird was rescued in a “torpor-like state” and were higher if rescued for “nest-related” reasons. Evaluation of treatment regimens administered at wildlife rehabilitation centers identified supportive care, including providing commercial nutrient-rich nectar plus solution, to significantly increase hummingbird survivability.
Discussion
Our results provide evidence of threats to hummingbirds in urban habitats, based on reasons for rescue and presentation to rehabilitation centers. Reasons for hummingbird admissions to three California wildlife rehabilitation centers were anthropogenic in nature (i.e., being associated with domestic animals, window collisions, and found inside a man-made structure) and constituted 25% of total admissions. There was a clear indication that supportive care, such as feeding a commercial nectar solution, and medical treatment significantly increased the odds of survival for rescued hummingbirds.
... Nutritional disorders are the most common non-infectious type of disease described in captive hummingbirds (3). Since hummingbirds have a unique diet of insects and nectar, replicating a hummingbird's diet can be quite difficult. ...
Retinol (vitamin A) and α-tocopherol (vitamin E) concentrations were measured in tissue samples (liver, heart, pectoral muscle, and brain) from Anna's Hummingbirds (Calypte anna). Hummingbirds were after-hatch year birds that were sourced from various rehabilitation centers throughout California. Tissues samples were analyzed using high-performance liquid chromatography (HPLC). Minimum, maximum, mean, standard deviation (SD), and median ppm concentrations were calculated for each vitamin and tissue sample type. A novel analytical method was developed to analyze small mass tissue samples, with the smallest sample mass being 0.05 g for which analysis can be performed. Mean ± standard deviation (SD) concentrations of retinol in hummingbird livers, hearts, and pectoral muscle samples were 269.0 ± 216.9 ppm, 1.8 ± 2.2 ppm, and 0.3 ± 0.1 ppm, respectively. Mean ± SD α-tocopherol concentrations were 6.9 ± 4.6 ppm, 5.5 ± 4.0 ppm, 3.7 ± 2.2 ppm, and 9.1 ± 3.2 ppm for liver, heart, pectoral muscle, and brain samples, respectively. Vitamin concentrations from varying tissue types were compared to determine which were best associated with liver concentrations, the most commonly analyzed tissue for these vitamins. For both retinol and α-tocopherol, heart samples were most strongly associated with the liver samples. The results of this study provide baseline retinol and α-tocopherol concentrations in different tissue types from Anna's hummingbirds. These baseline values may be utilized in conservation efforts to avoid hypervitaminosis and hypovitaminosis of rehabilitated and/or captive hummingbirds by providing guidelines for nutritional targets which could be assessed on post-mortem examinations. Post-mortem examination of birds and measurement of vitamin concentrations in tissues may allow for dietary changes that aid captive hummingbirds.
... In contrast, those compounds present in A. genuflexa are highly effective instead. Interestingly, there are a few reports of diseased hummingbirds that have been associated with bacteria of the family Enterobacteriaceae (Godoy et al. 2014), suggesting that they could be infected by these type of pathogens. ...
Many birds around the world use plant material to build nests that allow for hatching eggs and keeps chicks safe (Healy et al. 2015). Despite being a common phenomenon in nature, our knowledge of the mechanisms underlying how and why specific plants are selected for nest building is somewhat limited. Hummingbirds (Trochilidae) in particular depend strongly on plant materials to build their nests (Calvelo et al. 2006, Torres‐Dowdall et al. 2007). Hummingbirds commonly use mosses as nesting material because mosses can retain moisture for long periods and thereby prevent eggs from drying out (Breil and Moyle 1976, Blem and Blem 1994).
... In California, Allen's Hummingbird (Selasphorus sasin) is considered a species that is particularly vulnerable to climate change due to loss of breeding habitat (National Audubon Society 2014). Despite the hummingbird's ecologic importance, the effect of disease on hummingbird populations has not been well described (Godoy et al. 2014). There have been no serologic surveys or attempts at experimental infections for WNV in any hummingbird species. ...
Although West Nile virus (WNV) infects many avian species, the prevalence and impact of WNV in hummingbirds (Family Trochilidae) have not been described. We focused on hummingbird mortality and WNV infection using data from the state of California's Dead Bird Surveillance Program for the years 2005-2017. The overall prevalence of WNV in tested carcasses was 10.1% (49/486), with annual prevalence ranging from 0-28%. Prevalence by county ranged from 0-40% while prevalence by species ranged from 0-12%. We demonstrated that hummingbirds were naturally infected with WNV and displayed temporal and spatial patterns of infection consistent with trends observed in other avian species.
... Small birds are generally more sensitive to toxic chemicals than larger birds (Mineau et al. 1996), thus hummingbirds may offer great potential for monitoring bird exposure to pollutants. Since the diet of hummingbirds includes both insects and nectar from many sources, hummingbirds could be used as sentinel species for assessing environmental exposure to pollutants, including pesticides (Godoy et al. 2014). Given that bees and hummingbirds often forage in the same areas (Pritchard et al. 2017), it makes sense that these two ecologically similar groups of species may be exposed to the same suites of pollutants. ...
External feather rinses and homogenized whole-carcass tissue matrix from two hummingbird species found in California (Calypte anna and Archilochus alexandri) were analyzed for the presence of nine insecticides commonly used in urban settings. Using a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analytical method, samples were quantitatively tested for the following neonicotinoids: dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, imidacloprid, and sulfoxaflor. This analytical method was also used to qualitatively screen for the presence of approximately 150 other pesticides, drugs, and natural products. Feather rinsates from both hummingbird species had detectable concentrations of carbamate and neonicotinoid classes of insecticides. Combined results of the rinsate and homogenized samples (n = 64 individual hummingbirds) showed that 44 individuals (68.75%) were positive for one to four target compounds. This study documented that hummingbirds found in California are exposed to insecticides. Furthermore, feather rinsates and carcass homogenates are matrices that can be used for assessing pesticide exposure in small bird species. The small body size of hummingbirds limits traditional sampling methods for tissues and whole blood to evaluate for pesticide exposure. Thus, utilization of this analytical method may facilitate future research on small-sized avian species, provide insight into pesticide exposure, and ultimately lead to improved conservation of hummingbirds.
... The health of pollinators is of concern given the potential negative impacts of environmental contaminants combined with other stressors. 10,22 Some studies suggest that declines in biodiversity, as a result of habitat loss or conversion to agriculture, are exacerbated by insecticide use. 9 Mortality from pesticide exposure has been reported in multiple species of bats 5,18 and birds. ...
We developed and validated a liquid chromatography–high-resolution mass spectrometry (LC-HRMS) analytical method for quantitatively measuring pesticide concentrations in small-body avian tissue samples using homogenized 1–2-d-old chicken carcasses as the test matrix. We quantified the following key insecticides: sulfoxaflor (sulfoximine class) and the neonicotinoids dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, and imidacloprid. We used fortified chick carcass samples to validate method accuracy (80–125% recoveries), precision (<20% relative standard deviation), and sensitivity (≤1.2 ppb) for these targeted analytes. This method also uses full-scan, high-resolution MS to screen for the presence of a wide variety of other xenobiotics in bird carcasses. The utility of our screening process was demonstrated by the detection of carbaryl in some samples. This sensitive LC-HRMS analytical method for insecticide detection in a matrix of homogenized carcass is ideal for evaluating small birds for insecticide exposure. This novel whole-carcass method may allow for research studies of small-bodied, free-ranging avian species, and could provide insight regarding their exposure to multiple classes of environmental contaminants.
... Many properties related to contact network have been known to be associated with disease transmission in passerine birds [1,6,[12][13][14][15][16][17] and contact networks have also been widely used in wildlife for modeling pathogen transmission, and to identify super spreaders within the communities [18]. Risk of infections such as salmonellosis [19,20] or pox [21][22][23] has been hypothesized to be associated with feeder usage in birds. Pox viral infections have been documented in hummingbirds [22], so being able to elucidate whether hummingbird feeders play a role in the transmission of this disease would be beneficial. ...
Despite the popular use of hummingbird feeders, there are limited studies evaluating the effects of congregation, sharing food resources and increased contact when hummingbirds visit feeders in urban landscapes. To evaluate behavioral interactions occurring at feeders, we tagged 230 individuals of two species, Anna’s and Allen’s Hummingbirds, with passive integrated transponder tags and recorded their visits with RFID transceivers at feeders. For detecting the presence of tagged birds, we developed an RFID equipped feeding station using a commercially available antenna and RFID transceiver. Data recorded included the number of feeder visits, time spent at the feeder, simultaneous feeder visitation by different individuals, and identifying which feeders were most commonly visited by tagged birds. For the study period (September 2016 to March 2018), 118,017 detections were recorded at seven feeding stations located at three California sites. The rate of tagged birds returning to RFID equipped feeders at least once was 61.3% (141/230 birds). Females stayed at feeders longer than males per visit. We identified primary, secondary and tertiary feeders at Sites 2 and 3, according to the frequency of visitation to them, with a mean percentage of 86.9% (SD±19.13) visits to a primary feeder for each tagged hummingbird. During spring and summer, hummingbirds visited feeders most often in morning and evening hours. Feeder visits by males overlapped in time with other males more frequently than other females. The analysis of the contact network at the feeders did not distinguish any significant differences between age or sex. Although most hummingbirds visited the feeders during the daytime, our system recorded night feeder visitations (n = 7 hummingbirds) at one site. This efficient use of RFID technology to characterize feeder visitations and contact networks of hummingbirds in urban habitats could be used in the future to elucidate behaviors, population dynamics and community structure of hummingbirds visiting feeders.
... Many properties related to contact network have been known to be associated with disease transmission in passerine birds [1,6,[12][13][14][15][16][17] and contact networks have also been widely used in wildlife for modeling pathogen transmission, and to identify super spreaders within the communities [18]. Risk of infections such as salmonellosis [19,20] or pox [21][22][23] has been hypothesized to be associated with feeder usage in birds. Pox viral infections have been documented in hummingbirds [22], so being able to elucidate whether hummingbird feeders play a role in the transmission of this disease would be beneficial. ...
Despite the popular use of hummingbird feeders, there are limited studies evaluating the effects of congregation, sharing food resources and increased contact when hummingbirds visit feeders in urban landscapes. To evaluate behavioral interactions occurring at feeders, we tagged 230 individuals of two species, Anna’s and Allen’s Hummingbirds, with passive integrated transponder tags and recorded their visits with RFID transceivers at feeders. For detecting the presence of tagged birds, we developed an RFID equipped feeding station using a commercially available antenna and RFID transceiver. Data recorded included the number of feeder visits, time spent at the feeder, simultaneous feeder visitation by different individuals, and identifying which feeders were most commonly visited by tagged birds. For the study period (September 2016 to March 2018), 118,017 detections were recorded at seven feeding stations located at three California sites. The rate of tagged birds returning to RFID equipped feeders at least once was 61.3% (141/230 birds). Females stayed at feeders longer than males per visit. We identified primary, secondary and tertiary feeders at Sites 2 and 3, according to the frequency of visitation to them, with a mean percentage of 86.9% (SD±19.13) visits to a primary feeder for each tagged hummingbird. During spring and summer, hummingbirds visited feeders most often in morning and evening hours. Feeder visits by males overlapped in time with other males more frequently than other females. The analysis of the contact network at the feeders did not distinguish any significant differences between age or sex. Although most hummingbirds visited the feeders during the daytime, our system recorded night feeder visitations (n = 7 hummingbirds) at one site. This efficient use of RFID technology to characterize feeder visitations and contact networks of hummingbirds in urban habitats could be used in the future to elucidate behaviors, population dynamics and community structure of hummingbirds visiting feeders.
... Evaluating host-mite relationships is important when studying wild bird populations. Most of the literature reports for mites found on hummingbirds have predominantly been systematics studies, while hummingbird-mite ecological relationships remain relatively understudied [1]. Sarcoptiform mites in the group Psoroptidia (Astigmata) have been reported from numerous birds and include mite species whose effects on the host range from pathological (e.g. ...
Proctophyllodes huitzilopochtlii Atyeo & Braasch 1966 (Acariformes: Astigmata: Proctophyllodidae), a feather mite, was found on feathers collected from five hummingbird species in California. This mite has not been previously documented on feathers from Anna's (Calypte anna [Lesson 1829]) or Black-chinned (Archilochus alexandri [Bourcier & Mulsant 1846]) Hummingbirds. A total of 753 hummingbirds were evaluated for the presence of mites by species (Allen's n = 112; Anna's n = 500; Black-chinned n = 122; Rufous n = 18; Calliope n = 1), sex (males n = 421; females n = 329; 3 unidentified), and age (juvenile n = 199; after-hatch-year n = 549; 5 unidentified). Of these 753 hummingbirds evaluated, mites were present on the rectrices of 40.9% of the birds. Significantly more Anna's Hummingbirds were positive for rectricial mites (59.2%) compared with 8.2% of Black-chinned, 0.9% of Allen's, 5.6% of Rufous Hummingbirds, and 0% for Calliope (p-value < 0.0001). Across all hummingbird species, male hummingbirds (44.9%) had a higher prevalence of rectricial mites compared to female hummingbirds (36.2%; p-value = 0.004), while juvenile hummingbirds (46.2%) had a non-significantly higher prevalence compared to after-hatch-year hummingbirds (39.0%; p-value = 0.089). On average, the percentage of the long axis of the rachis occupied by mites for the outer rectrices (R4 and R5) was 19%, compared to 11% for inner rectrices (R1 and R2), a significant difference (p-value
... Hummingbirds are a widespread and abundant taxon in the Americas, and are under-studied both in terms of the effects of trace elements on their health as well as their potential as indicators of pollination services and urban ecosystem health (Godoy et al., 2014). Despite their importance as pollinators, the relationship between hummingbirds and environmental contamination is largely unknown with the exception of one published study (Góngora et al., 2016). ...
Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The results from this study provide a benchmark for the distribution of trace element concentrations in feather and tissue samples from hummingbirds and suggests a reference mark for exceeding normal. Lastly, pollinating avian species are minimally represented in the literature as bioindicators for environmental trace element contamination. Given that trace elements can move through food chains by a variety of routes, our study indicates that hummingbirds are possible bioindicators of environmental trace element contamination.
Hummingbirds (Trochilidae) are sensitive to environmental changes because of their extraordinary ecology, metabolism, and the highest red blood cell counts found in any vertebrate. These physiological attributes may render hummingbirds particularly susceptible to the effects of haemosporidian (blood parasite) infections. Much of the research on haemosporidians in hummingbirds has been conducted in South America; less is known about haemosporidian diversity and prevalence in North America. We sought to determine the prevalence and diversity of haemosporidians in a high-elevation species, the Broad-tailed Hummingbird (Selasphorus platycercus). Blood samples (N = 314) from 25 sites in Colorado and Wyoming were screened for haemosporidians using microscopy (n = 311) and PCR (n = 301). Both microscopy and sequencing diagnostic techniques detected haemosporidians in the same 5 hummingbirds, with an overall prevalence of 1.59%. Positive samples were sequenced at the cytochrome b gene and identified Haemoproteus archilochus and two Haemoproteus sp. not previously detected in North America. No parasites of the genera Plasmodium or Leucocytozoon were detected. Our study provides the first report of the prevalence and diversity of haemosporidians in Broad-tailed Hummingbirds in the Rocky Mountains.
Animals with a slow pace of life and high mass-specific metabolic rates are expected to invest less in innate immune responses. We measured skin inflammation and the resting metabolic rate (RMR) of ruby-throated hummingbirds ( Archilochus colubris) after their immune system was challenged with phytohemagglutinin (PHA) and compared with the response of birds injected a saline solution. The PHA test measures the inflammatory process, a component of the innate response. Ruby-throated hummingbirds belong to a group that is under-represented in avian immunological studies characterized by a slow pace of life and fast metabolic rate. Hummingbirds developed an inflammatory response that lasted <28 h. PHA injection produced a significant increment of RMR (up to ~13%) with respect to RMR values after the injection of the saline solution indicating that immune response involved a metabolic cost for hummingbirds. This increment lies within the range of values previously reported for birds injected PHA (5%–29%).
Avian pox is a viral disease documented in a wide range of bird species. Disease related detrimental effects can cause dyspnea and dysphagia, therefore birds with high metabolic requirements, such as hummingbirds, are especially vulnerable. Hummingbirds have a strong presence in California, especially in urban environments; however, little is understood regarding the impact of pox virus on hummingbird populations. Diagnosing pox infections relies on obtaining a tissue biopsy that poses significant bird risks and field challenges. Understanding the ecology of hummingbird pox viral infections could be advanced by a minimally invasive ante-mortem diagnostic method. This study’s goal was to address this gap in understanding if pox infections can be diagnosed using integumentary system samples besides tissue biopsies. To meet this goal, we tested multiple integumentary sample types and tested them using a quantitative real-time PCR assay. A secondary study goal was to determine which sample types (ranging from minimally to highly invasive sampling) were optimal for identifying infected birds.
Methodology/Principal Findings:
Lesion tissue, pectoral muscle, feathers, toenail, blood, and swabs (both lesion tissue and non-lesion tissues) were taken from live birds and carcasses of two species of hummingbirds found in California. To maximize successful diagnosis, especially for samples with low viral load, a real-time quantitative PCR assay was developed for detecting the hummingbird-specific Avipoxvirus 4b core protein gene. Avipoxvirus DNA was successfully amplified from all sample types across 27 individuals. Our results were then compared to those of conventional PCR. Comparisons were also made between sample types utilizing lesion tissue samples as the gold standard.
Conclusions/Significance:
Hummingbird avian pox can be diagnosed without relying on tissue biopsies. Feather samples can be used for diagnosing infected birds and reduces sampling risk. A real-time PCR assay detected viral DNA in various integumentary system sample types and could be used for studying hummingbird disease ecology the future.
Human provisioning can shape resource availability for wildlife, but consequences for microbiota availability and exchange remain relatively unexplored. Here, we characterized microbial communities on bills and faecal material of hummingbirds and their food resources, including feeders and floral nectar. We experimentally manipulated bird visitation to feeders and examined effects on sucrose solution microbial communities. Birds, feeders and flowers hosted distinct bacterial and fungal communities. Proteobacteria comprised over 80% of nectar bacteria but feeder solutions contained a high relative abundance of Proteobacteria, Firmicutes and Actinobacteria. Hummingbirds hosted bacterial taxa commonly found in other birds and novel genera including Zymobacter [Proteobacteria] and Ascomycete fungi. For feeders, bird-visited and unvisited solutions both accumulated abundant microbial populations that changed solution pH, but microbial composition was largely determined by visitation treatment. Our results reveal that feeders host abundant microbial populations, including some bird-associated microbial taxa. Microbial taxa in feeders were primarily non-pathogenic bacteria and fungi but differed substantially from those in floral nectar. These results demonstrate that human provisioning influences microbial intake by free-ranging hummingbirds; however, it is unknown how these changes impact hummingbird gastrointestinal flora or health.
The northern Andes, with their steep elevational and climate gradients, are home to an exceptional diversity of flora and fauna, particularly rich in avian species that have adapted to divergent ecological conditions. With this diversity comes the opportunity for parasites to exploit a wide breadth of avian hosts. However, little research has focused on examining the patterns of prevalence and lineage diversity of avian parasites in the Andes. Here, we screened a total of 428 birds from 19 species (representing nine families) and identified 133 infections of avian haemosporidia (31%), including lineages of Plasmodium, Haemoproteus, and Leucocytozoon. We document a higher prevalence of haemosporidia at higher elevations and lower temperatures, as well as an overall high diversity of lineages in the northern Andes, including the first sequences of haemosporidians reported in hummingbirds (31 sequences found in 11 species within the family Trochilidae). Double infections were distinguished using PHASE, which enables the separation of distinct parasite lineages. Results suggest that the ecological heterogeneity of the northern Andes that has given rise to a rich diversity of avian hosts may also be particularly conducive to parasite diversification and specialization.
Abstract Avian poxvirus (genus Avipoxvirus, family Poxviridae) is an enveloped double-stranded DNA virus that may be transmitted to birds by arthropod vectors or mucosal membrane contact with infectious particles. We characterized the infection in Anna's Hummingbird (Calypte anna; n = 5 birds, n = 9 lesions) by conducting diagnostic tests on skin lesions that were visually similar to avian poxvirus lesions in other bird species. Skin lesions were single or multiple, dry and firm, pink to yellow, with scabs on the surface, and located at the base of the bill, wings, or legs. Microscopically, the lesions were characterized by epidermal hyperplasia and necrosis with ballooning degeneration, and intracytoplasmic inclusions (Bollinger bodies) in keratinocytes. The 4b core gene sequence of avian poxvirus was detected by PCR in samples prepared from lesions. Nucleotide sequences were 75-94% similar to the sequences of other published avian poxvirus sequences. Phylogenetic analyses showed that the Anna's Hummingbird poxvirus sequence was distinguished as a unique subclade showing similarities with sequences isolated from Ostrich (Struthio camelus), Wild Turkey (Meleagris gallopavo), falcons (Falco spp.), Black-browed Albatross (Diomedea melanophris), Mourning Dove (Zenaida macroura) and White-tailed Eagle (Haliaeetus albicilla). To our knowledge this is the first published report of definitive laboratory diagnosis of avian poxvirus in a hummingbird. Our results advance the science of disease ecology in hummingbirds, providing management information for banders, wildlife rehabilitators, and avian biologists.
The infestation by feather-mites on hummingbirds was studied. A total of 86 birds were captured with mist-nest at the Engenho Independência, municipality of Vicência, Pernambuco, Brazil. Of those, 59 individuals (68.6%) were infested by feather-mites of the genera Trochilodectes Park & Atyeo, 1971; Toxerodectes Park & Atyeo, 1971; and Schizodectes Park & Atyeo, 1972 (Proctophyllodidae). The most infested body parts were the remiges and rectrizes. The infestation prevalence varied between 40.0% and 78.4%, and was higher during the dry season for the three bird species evaluated. Keywords: hummingbirds, ectoparasites, feather-mites.
We estimated annual apparent survival, recruitment, and rate of population growth of breeding Ruby-throated Hummingbirds (Archilochus colubris), while controlling for transients, by using 18 years of capture-mark-recapture data collected during 1984–2001 at Hilton Pond Center for Piedmont Natural History near York, South Carolina. Resident males had lower apparent survival (0.30 ± 0.05 SE) than females (0.43 ± 0.04). Estimates of apparent survival did not differ by age. Point estimates suggested that newly banded males were less likely than females to be residents, but standard errors of these estimates overlapped (males: 0.60 ± 0.14 SE; females: 0.67 ± 0.09). Estimated female recruitment was 0.60 ± 0.06 SE, meaning that 60% of adult females present in any given year had entered the population during the previous year. Our estimate for rate of change indicated the population of female hummingbirds was stable during the study period (1.04 ± 0.04 SE). We suggest an annual goal of ≥64 adult females and ≥64 immature females released per banding area to enable rigorous future tests for effects of covariates on population dynamics. Development of a broader cooperating network of hummingbird banders in eastern North America could allow tests for regional or metapopulation dynamics in this species.
Sobrevivencia Anual y Reclutamiento en una Población del Picaflor Archilochus colubris Excluyendo el Efecto de Individuos Ocasionales
Resumen. Estimamos la sobrevivencia anual aparente, reclutamiento y tasa de crecimiento en una población reproductiva del picaflor Archilochus colubris, controlando por la presencia de individuos ocasionales. Utilizamos datos de 18 años de captura-marcaje-recaptura colectados entre 1984 y 2001 en Hilton Pond Center for Piedmont Natural History en cercanías de York, Carolina del Sur. Los machos residentes presentaron una sobrevivencia aparente menor (0.30 ± 0.05 EE) que las hembras (0.43 ± 0.04). Las estimaciones de la sobreviviencia aparente no difirieron entre edades. Estimaciones puntuales sugirieron que los machos marcados por primera vez tuvieron una menor probabilidad de ser residentes que las hembras, pero los errores estándar de estas estimaciones se sobrepusieron (machos: 0.60 ± 0.14 EE; hembras: 0.67 ± 0.09 EE). Para las hembras el reclutamiento estimado fue 0.60 ± 0.06 EE, lo que significa que el 60% de las hembras adultas presentes en un año determinado entraron a la población durante el año anterior. Nuestra estimación de la tasa de cambio indicó que la población de picaflores hembra fue estable durante el período de estudio (1.04 ± 0.02 EE). Para permitir futuras pruebas rigurosas sobre las covariables asociadas a las dinámicas poblacionales, sugerimos una meta anual de ≥64 hembras adultas y ≥64 hembras inmaduras liberadas por área de anillado. La creación de una amplia red cooperativa de anilladores de picaflores en el este de Norteamérica podría permitir estudiar y entender mejor las dinámicas regionales o metapoblacionales de esta especie.
Gastrointestinal and external parasites from 12 Green-backed Firecrown (Sephanoides sephaniodes) were collected between January 2004 and December 2008 from the Biobío Region south-central Chile and Santiago (central Chile). Helminths collected included 1 trematode species (Mosesia sp.) and 1 cestode species (Hymenolepis trinidadensis). The mite Proctophyllodes huitzilopchtlii was the only ectoparasite species found. All these parasites represent new records for Chile and the first parasites reported for this host species.
Laboratory and field experiments were conducted on the island of Hawaii from 1977-1980 in an effort to determine the impact of avian malaria on the forest birds. At 16 study sites from sea level to tree line in mesic and xeric habitat, birds were captured and bled to determine the host and altitudinal distribution of blood parasites. In the laboratory, six bird species were challenged with malarial parasites to measure host susceptibility. Distributions, activity cycles, and transmission potentials of malarial parasite vectors were also analyzed. One species of Plasmodium was present from sea level to tree line, concentrated in the mid-elevational ranges in the ecotonal area where vectors and native birds had the greatest overlap. Native forest birds were: (a) more susceptible to malaria than were introduced species; (b) most likely to have malaria during the nonbreeding, wet season; (c) found ranging lower in xeric than in mesic forests; and (d) found to have a lower prevalence of malaria in xeric forests. Temporal as well as elevational differences in prevalence and parasitemia levels of wild birds were apparent throughout the annual cycle, a result of differing host and parasite responses to biotic and abiotic factors. Avian malaria probably did not reach epizootic proportions on Hawaii until after @?1920. However, since that time it has had a negative impact on the population dynamics of the native forest birds and is today a major limiting factor, restricting both abundance and distribution of these species on the island. In response, a number of native bird species have developed immunogenetic and behavioral responses that reduce the impact of the parasite on host populations.
Un genre et une espèce nouveaux sont décrits à partir de puces trouvées dans un nid habité d’oiseau-mouche Oreotrichulus estella (d’Orbigny & Lafresnaye, 1838). Ce taxon montre des affinités en particulier avec Dasypsyllus Baker, 1908, parasite d’oiseaux, cosmopolite sauf en régions afrotropicale et australe, et Smitipsylla Lewis, 1971, parasite d’écureuils volants (Anomaluridae) en région orientale.
Twenty-five of 26 hummingbirds (Trochilidae) from 7 species previously maintained in an aviary on a commercial nectar substitute for 13 years, died over 3-month period. Gross necropsy was inconclusive; however, staining of liver and intestinal tissue showed high levels of Fe deposition. Analysis of separate bags (n=9) of the nectar product, with identical lot numbers, showed variation in Fe content from 26 to 886 mg/kg, compared to a manufacturer's specification of 40 mg/kg. A low Fe (20 mg/kg) diet was formulated for reintroduction of birds to the aviary. Samples of nectar replacement products (n=14 from 9 manufacturers) were analyzed for an array of nutrients including proximate composition, fat-soluble vitamins A and E, and minerals. Wide ranges in composition were detected among products, with no consistent variability (i.e. products with high values for one nutrient didn't necessarily have high values for any others). Crude protein ranged from 1.7 to 23.1, crude fat ranged from 1.9 to 12.8, CHO content (calculated) from 37.9 to 75.9, and ash, 0.67 to 7.0 (all % dry matter, DM, basis). Ca and P (% DM) varied 10 to 220-fold, from low concentrations (0.12 and 0.003, respectively), to highs of 1.24 and 0.67. Ca:P ratios ranged from 0.75:1 to 154:1. Vitamins A and E (IU/g) varied from lows of 0.33 and 0.005, respectively, to highs of 4,932 and 2.71, respectively. Fe content varied almost 800-fold, from 4.4 to 3,485 mg/kg DM. These analyses, in conjunction with the reported pathology, suggest a need to review Fe levels in commercial replacement products used in captive feeding programs for feeding nectarivorous species.
Nine species of mites of the genus Proctolaelaps were collected in flowers or phoretic in the nares of hummingbirds in Trinidad. Previously named species P. kirmsei, P. glaucis, and P. belemensis are redescribed, and six new species are described: P. jurgatus, P. mermillion, P. rabulatus, P. contumex, P. certator, and P. contentiosus. Proctolaelaps belemensis cyanocompsae is raised to specific status. Host plants are given for all species except P. mermillion, which was collected only from a hummingbird host. New World flower-inhabiting Proctolaelaps are grouped into two hypothetically monophyletic lineages, the kirmsei-group and the belemensis-group, on the basis of adult morphology. A key to the nine Trinidadian species is given.
Ascid mites (Ascidae) from various southwestern Colombian localities and altitudes were collected from the nasal cavities of hummingbirds and/or from angiosperm flowers visited by three birds. Twelve species, belonging to the genera Rhinoseius Baker and Yunker, 1964, Proctolaelaps Berlese, 1923 and Lasioseius Berlese, 1916, have been identified, and among them three are new: Rhinoseius caucaensis, R. haplophaedia and Lasioseius peterfuldi. The female of Rhinoseius panamensis Fain, Hyland and Aitken, 1977 is described for the first time.
Determinamos la prevalencia y distribución altitudinal de aves de bosque infectadas con viruela aviaria (Poxvirus avium) en 16 localidades de Hawai, desde el nivel del mar hasta la línea de bosque en hábitats húmedos y secos, entre 1977 y 1980. Muestras de las lesiones fueron cultivadas en el laboratorio para confirmar la identificación de Poxvirus avium. Las aves silvestres infectadas fueron llevadas al laboratorio para evaluar diferencias en el curso de la infección entre especies nativas e introducidas. También documentamos las distribuciones y los ciclos de actividad de los vectores potenciales de Poxvirus avium. Las aves nativas del bosque (1) fueron más susceptibles a infecciones con viruela aviaria que las aves introducidas, (2) presentaron mayor probabilidad de ser infectadas durante la estación húmeda, y (3) tuvieron mayor prevalencia en bosques húmedos que en bosques secos. La viruela aviaria fue registrada en aves de bosque a todas las elevaciones, pero los niveles más altos se registraron a elevaciones medias (1,200 m), donde los vectores y las aves nativas presentaron una mayor superposición. Las diferencias temporales y de elevación en prevalencia fueron evidentes a lo largo del ciclo anual. La viruela aviaria probablemente no alcanzó proporciones epizoóticas en Hawai hasta después de la introducción del mosquito y de aves domésticas a principios de 1800, y desde entonces ha tenido un efecto negativo en la dinámica poblacional de las aves nativas de bosque. Hoy en día, esta enfermedad introducida es un factor importante que debería ser considerado en futuros esfuerzos de conservación dirigidos a recuperar las aves nativas de bosque en Hawai.
We estimated annual apparent survival, recruitment, and rate of population growth of breeding Ruby-throated Hummingbirds (Archilochus colubris), while controlling for transients, by using 18 years of capture-mark-recapture data collected during 1984–2001 at Hilton Pond Center for Piedmont Natural History near York, South Carolina. Resident males had lower apparent survival (0.30 ± 0.05 SE) than females (0.43 ± 0.04). Estimates of apparent survival did not differ by age. Point estimates suggested that newly banded males were less likely than females to be residents, but standard errors of these estimates overlapped (males: 0.60 ± 0.14 SE; females: 0.67 ± 0.09). Estimated female recruitment was 0.60 ± 0.06 SE, meaning that 60% of adult females present in any given year had entered the population during the previous year. Our estimate for rate of change indicated the population of female hummingbirds was stable during the study period (1.04 ± 0.04 SE). We suggest an annual goal of ≥64 adult females and ≥64 immature females released per banding area to enable rigorous future tests for effects of covariates on population dynamics. Development of a broader cooperating network of hummingbird banders in eastern North America could allow tests for regional or metapopulation dynamics in this species. Sobrevivencia Anual y Reclutamiento en una Población del Picaflor Archilochus colubris Excluyendo el Efecto de Individuos Ocasionales Resumen. Estimamos la sobrevivencia anual aparente, reclutamiento y tasa de crecimiento en una población reproductiva del picaflor Archilochus colubris, controlando por la presencia de individuos ocasionales. Utilizamos datos de 18 años de captura-marcaje-recaptura colectados entre 1984 y 2001 en Hilton Pond Center for Piedmont Natural History en cercanías de York, Carolina del Sur. Los machos residentes presentaron una sobrevivencia aparente menor (0.30 ± 0.05 EE) que las hembras (0.43 ± 0.04). Las estimaciones de la sobreviviencia aparente no difirieron entre edades. Estimaciones puntuales sugirieron que los machos marcados por primera vez tuvieron una menor probabilidad de ser residentes que las hembras, pero los errores estándar de estas estimaciones se sobrepusieron (machos: 0.60 ± 0.14 EE; hembras: 0.67 ± 0.09 EE). Para las hembras el reclutamiento estimado fue 0.60 ± 0.06 EE, lo que significa que el 60% de las hembras adultas presentes en un año determinado entraron a la población durante el año anterior. Nuestra estimación de la tasa de cambio indicó que la población de picaflores hembra fue estable durante el período de estudio (1.04 ± 0.02 EE). Para permitir futuras pruebas rigurosas sobre las covariables asociadas a las dinámicas poblacionales, sugerimos una meta anual de ≥64 hembras adultas y ≥64 hembras inmaduras liberadas por área de anillado. La creación de una amplia red cooperativa de anilladores de picaflores en el este de Norteamérica podría permitir estudiar y entender mejor las dinámicas regionales o metapoblacionales de esta especie.
Estudiamos los efectos de las infecciones crónicas de malaria aviaria (Plasmodium relictum) en el éxito reproductivo de un mielero nativo de Hawai (Hemignathus virens). Las infecciones crónicas de malaria en los padres de ambos sexos no redujeron de modo significativo el éxito reproductivo medido como el tamaño de la nidada, el éxito de eclosión, el peso de los volantones, el número de pichones que dejaron el nido, el éxito de nidificación (tasa diaria de supervivencia) ni la supervivencia mínima de los volantones. De hecho, el éxito de nidificación de las parejas con machos infectados de modo crónico fue significativamente mayor que el de aquellos con machos no infectados (76% vs. 38%), y los pichones que tuvieron al menos un padre que había sobrevivido la fase pico de la infección de malaria presentaron una probabilidad mayor de ser vistos nuevamente el año próximo (25% vs. 10%). La reproducción y la supervivencia de las aves infectadas fueron suficientes como para mantener una tasa de crecimiento poblacional per cápita >1, lo que sugiere que los individuos con infecciones crónicas de H. virens pueden mantener una población creciente.
Finch (Carpodacus mexicanus) conjunctivitis is an example of the rapid geographic spread that can result from disease emergence in naive populations. That event was neither novel nor transient relative to its occurrence or effects. Disease emergence and reemergence are hallmarks of the latter part of the twentieth century (Center for Disease Control 1994, Levins et al. 1994, DaSilva and Laccarino 1999, Gratz 1999). Current examples involving domestic animals include the problems in Europe with bovine spongiform encephalopathy (BSE, or ‘‘mad cow disease’’) (Brown 2001) and foot-and-mouth disease (FMD) (Kitching 1999). Human health has been affected by diseases caused by an array of viruses (Morse 1993, Nichol et al. 1993, Murphy and Nathanson 1994), bacteria (Dennis 1998, DaSilva and Laccarino 1999), rickettsia (Walker and Dumier 1996, Azad et al. 1997), protozoans (Tuerrant 1997, Saini et al. 2000), and metazoan parasites (Hildreth et al. 1991, Gubler 1998), as well as other causes. Acquired immune deficiency syndrome (AIDS) has received the most notoriety of those diseases (Hahn et al. 2000, Schwartlander et al. 2000). A similar pattern exists on a global scale for free-ranging wildlife populations (Table 1) (Friend 1994, 1995; Epstein et al. 1998, Daszak et al. 2000). However, in comparison to disease emergence affecting humans and domestic animals, response to emerging diseases of wildlife is generally superficial. We present concepts and data to support our contention that failure to adequately address disease emergence in free-ranging wildlife is resulting in a diminished capability to achieve and sustain desired geographic distributions and population abundance for species of wild birds, including some threatened and endangered avifauna.
The Honduran Emerald Amazilia luciae is endemic to dry forests of Honduras and currently recognised as ‘Critically Endangered.’ Here we present the first modern assessment of its distribution, ecology, and conservation, based partly on our rediscovery of the species in western Honduras and on our observations in three Honduran departments. We found that dry forests inhabited by the emerald differed in structure and species composition between eastern and western Honduras, where we observed emeralds in open-canopied deciduous thorn forests and closed-canopied semi-deciduous woodlands, respectively. We interpret these differences in light of the geological and anthropogenic origins of dry forests in Honduras, and discuss the implications of such origins for the conservation of dry forests. Although our findings expand the known distribution and population size of the species, its status as ‘Critically Endangered’ is warranted due to its restricted distribution in dry forest fragments and increasing human pressures on this habitat.
In 1992 and 1993, unknown diseases killed 250-300 King Penguins Aptenodytes patagonicus and an estimated 5-10 thousand Macaroni Penguins Eudyptes chrysolophus at sub-Antarctic Marion Island. At the same island, an outbreak of avian cholera Pasteurella multocida during November 2004 killed approximately 2000 Macaroni Penguins at Kildalkey Bay. Other breeding colonies of Macaroni Penguins and other species of seabirds at the island were not affected at the time. Procedures for reporting and dealing with such outbreaks are now being developed.
We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population.
Efectos de las Infecciones Crónicas de Malaria Aviaria (Plasmodium relictum) en el Éxito Reproductivo de Hemignathus virens
We determined prevalence and altitudinal distribution of forest birds infected with avian pox at 16 locations on Hawaii, from sea level to tree line in mesic and xeric habitats, during 1977–1980. Isolates from lesions were cultured in the laboratory for positive identification of Poxvirus avium. Infected birds from the wild were brought into the laboratory to assess differences in the course of infection in native versus introduced species. We also documented distributions and activity cycles of potential avian pox vectors.>Native forest birds were (1) more susceptible to avian pox infection than were introduced species, (2) most likely to be infected during the wet season, and (3) found to have a higher prevalence in mesic when compared to xeric forests. Avian pox occurred in forest birds at all elevations, but highest levels were in the mid-elevational ranges (∼1,200 m) where vectors and native birds had the greatest overlap. Temporal and elevational differences in prevalence were apparent throughout the annual cycle. Avian pox probably did not reach epizootic proportions on Hawaii until after introduction of the mosquito and domestic birds in the early 1800s, and since then has had a negative effect on the population dynamics of native forest birds. Today, this introduced disease is an important factor that should be considered in future conservation efforts that are directed at the recovery of native forest birds in Hawaii.
The infestation by feather-mites on hummingbirds was studied. A total of 86 birds were captured with mist-nest at the Engenho Independência, municipality of Vicência, Pernambuco, Brazil. Of those, 59 individuals (68.6%) were infested by feather-mites of the genera Trochilodectes Park & Atyeo, 1971; Toxerodectes Park & Atyeo, 1971; and Schizodectes Park & Atyeo, 1972 (Proctophyllodidae). The most infested body parts were the remiges and rectrizes. The infestation prevalence varied between 40.0% and 78.4%, and was higher during the dry season for the three bird species evaluated.
A systematic revision is presented for the genus Proctophyllodes. Data on the bionomics, morphology, and host-parasite relationships are included.
Microsporidiosis was identified as a cause of enteritis in wild, migratory hummingbirds (Calypte anna). Electron microscopic examinations of parasites showed microsporidian spores with a double spore coat and a polar filament containing four to six coils, compatible with the genus Encephalitozoon. Molecular analysis of ribosomal RNA genes further identified the parasites from droppings and small intestinal segments as Encephalitozoon hellem, genotype I. Microsporidial spores were identified in 19% of droppings from C. anna, Archilochus alexandri and Selasporus sasin using Gram or modified trichrome staining methods. Since E. hellem is an opportunistic pathogen in immunocompromised humans, the pathogenic potential in avian hosts, the zoonotic potential of this parasite, and the role of birds as reservoirs needs to be further explored.
Rhamphocaulinae, new subfamily, Rhamphocaulus, new genus, with Proctophyllodes (Alloptes) aviculocaulis Trouessart (1886) as type species and 2 new species, R. sinuatus and R. vachoni, are described.
The makeup of parasite communities is the result, among other factors, of interactions between the evolutionary history and ecological characteristics of hosts. This study evaluates the relative importance of some ecological factors (host body size, diet, habitat, latitude, and the mean number of parasite individuals per host) as determinants or correlates of parasite community richness in vertebrates, before and after controlling for potential effects of host phylogenetic relationships. Data were obtained from the literature on 596 parasite communities belonging to one of four distinct types: gastrointestinal parasite communities of fish, birds, or mammals, and ectoparasite communities of fish. There were positive correlations between the number of hosts sampled and mean species richness of the parasite community of each genus. In analyses treating host genera as independent statistical observations and using estimates of parasite species richness corrected for host sample size, positive correlations were observed between richness and host body size in gastrointestinal communities of all three groups of vertebrates. The mean number of parasite individuals per host also was correlated positively with species richness. In fish, richness increased with increases in the proportion of animal food in the host diet. Aquatic birds had richer parasite communities than their terrestrial counterparts, whereas marine fish had richer gastrointestinal parasite communities than freshwater fish. The richness of ectoparasite communities on fish showed no association with any of the ecological variables investigated. Using host genera as independent points in the analyses may lead to biased results since some host lineages are descended from recent common ancestors, and are therefore not truly independent. The comparative analysis was repeated using phylogenetically independent contrasts derived from the phylogeny of hosts. Once the effects of host phylogeny were removed, somewhat different results were obtained: host body size showed no relationship with parasite species richness in birds, and there was no evidence that habitat transitions resulted in significant changes in parasite species richness in any of the types of communities studied. Of the ecological factors studied, the comparative analyses suggest that only host body size can be an important determinant of parasite community richness in certain host groups. This study illustrates clearly the need to control for phylogeny in investigations of host-parasite interactions.
Lyme disease has become a significant infectious disease concern in the Western United States. This study investigates the ecology and transmission of the spirochete causative agent of Lyme disease, Borrelia burgdorferi, in an area of Northern California, USA by examining the host selection of different tick species and life stages. Ticks were collected from a wildlife rehabilitation center near the San Francisco Bay to investigate disease transmission and how it relates to tick and host animal ecology in the area. Tick species, tick life stage, and host species were compared to infer their relationship to local Lyme disease transmission. Despite lower than expected sample sizes, this study uncovered some evidence of novel host selection relationships, and provided an initial evaluation of this new parasite collection method. This research has allowed for valuable insight into the enzootic maintenance and cycling of spirochete populations and the relative importance of different ticks and vertebrate hosts to this process.
Abstract Avian poxvirus (genus Avipoxvirus, family Poxviridae) is an enveloped double-stranded DNA virus that may be transmitted to birds by arthropod vectors or mucosal membrane contact with infectious particles. We characterized the infection in Anna's Hummingbird (Calypte anna; n = 5 birds, n = 9 lesions) by conducting diagnostic tests on skin lesions that were visually similar to avian poxvirus lesions in other bird species. Skin lesions were single or multiple, dry and firm, pink to yellow, with scabs on the surface, and located at the base of the bill, wings, or legs. Microscopically, the lesions were characterized by epidermal hyperplasia and necrosis with ballooning degeneration, and intracytoplasmic inclusions (Bollinger bodies) in keratinocytes. The 4b core gene sequence of avian poxvirus was detected by PCR in samples prepared from lesions. Nucleotide sequences were 75-94% similar to the sequences of other published avian poxvirus sequences. Phylogenetic analyses showed that the Anna's Hummingbird poxvirus sequence was distinguished as a unique subclade showing similarities with sequences isolated from Ostrich (Struthio camelus), Wild Turkey (Meleagris gallopavo), falcons (Falco spp.), Black-browed Albatross (Diomedea melanophris), Mourning Dove (Zenaida macroura) and White-tailed Eagle (Haliaeetus albicilla). To our knowledge this is the first published report of definitive laboratory diagnosis of avian poxvirus in a hummingbird. Our results advance the science of disease ecology in hummingbirds, providing management information for banders, wildlife rehabilitators, and avian biologists.
The current article surveys the process of taxonomic affiliation of the genus Arostellina, remarkable for the controversity in expert opinions it has fuelled and for the number of erroneous decisions it has generated. A new subfamily Arostellininae, subfam. n., belonging to the family Dilepididae, has been substantiated. It is distinguished by the absence of rostellum and armature of scolex and by acraspedote strobila. Mature individuals inhabit the intestine of the hummingbird (Trochili). These cestodes and their hosts belong to the biogeocenological category of primary atmobionts, insects indicated as the probable intermediate hosts. From the representatives of the subfamily Dilepidinae, to which the genus Arostellina and the subfamily Neoliginae Spassky, 1980, are attributed, Arostellininae differ in the retiform structure of the ovary, vitelline gland and uterus, acraspedote strobila, absence of rostellum and affiliation of their definite hosts to the suborder Trochili.
An analysis of correlations between social systems, food disperson, and behavioral and morphological attributes related to predation vulnerability in a tropical avifauna indicates the following results and conclusions: (1) Solitary foraging is typical of species whose characteristics of activity, watchfulness, size, and habitat intuitively indicate reduced conspicuousness and vulnerability to relevant predators. (2) Active arboreal birds frequently forage in flocks. Their active search for food in the more open strata of the forest indicates greater vulnerability to predation in comparison to the rest of the avifauna. (3) Flocking is more probably an adaptation reducing susceptibility to predation than a development primarily determined by characterstics of food dispersion. Relative support is based on the number of exceptions to predicted correlations. (4) Among flocking species, flock composition is based to a large extent upon resource dispersion. Species with clumped resources flock intraspecifically;...
Despite their diversity and extreme popularity with humans, hummingbirds have received relatively little attention from a conservation standpoint. The Hummingbird Monitoring Network (HMN) was started in 2002 to address the conservation needs of this family of birds. In this ini- tial assessment of the conservation needs for the most threatened hummingbird species, we built a composite map of all their ranges and summarized their attributes. Forty-eight species (over 14% of the family) are vulnerable, threatened, or endangered. They live at all elevations, from sea-level to 4800 m. Most rely on forests, are range-restricted, and do not use man-made habitats, such as gardens and agricultural areas. The primary habitats with the highest number of at risk species are montane evergreen forests (18 species), tropical lowland evergreen forests (8 species), and elfi n forests (6 spe- cies). Based upon the number of vulnerable, threatened, and endangered hummingbird species, the Tropical Andes and southern Mexico appear to be areas with the highest threats. This vulnerability assessment for the family of hummingbirds provides information that can help focus conservation attention in areas and habitats where the most threatened hummingbird species live.
Every year, millions of households provide huge quantities of supplementary food to wild birds. While alteration of the natural dynamics of food supply represents a major intervention in avian ecology, we have a remarkably limited understanding of the impacts of this widespread pastime. Here, we examine the many and varied responses of birds to supplementary feeding at backyard feeders - in large-scale management projects and in focused academic studies - and evaluate population responses to the bird-feeding phenomenon. Our review encompasses a wide range of species, from songbirds to raptors, and compares provisioning with a variety of foods, at different times of year and in different locations. We consider positive impacts, such as aiding species conservation programs, and negative ones, such as increased risk of disease transmission. It seems highly likely that natural selection is being artificially perturbed, as feeding influences almost every aspect of bird ecology, including reproduction, behavior, demography, and distribution. As the effects of bird feeding cascade through ecosystems and interact with processes of environmental change, we suggest areas for future research and highlight the need for large-scale experiments, with a particular focus on the backyards of an increasingly urban and generous, but sometimes fickle, human population.
The female of a new species, Lasioseius aquilarumn. sp. (Acari: Ascidae), is described and illustrated. It belongs to the L. drosophili group according to Karg's (1980) classification and represents the fourth species in the genus known from hummingbirds and hummingbird pollinated flowers. It is the first record of the genus in Costa Rica (Central America).
The haemoproteids of the hummingbird family Trochilidae are reviewed and the hosts and parasite distribution summarized. Haemoproteus archilochus Coatney and West, 1938 is redescribed from the type material. Haemoproteus trochili n.sp. and Haemoproteus witti n.sp. are described from Eutoxeres aquila collected in Colombia and Trochilus polytmus collected in Jamaica, respectively.
The emergence of highly pathogenic avian influenza (HPAI) viruses has raised concerns about the role of wild birds in the spread and persistence of the disease. In 2005, an outbreak of the highly pathogenic subtype H5N1 killed more than 6,000 wild waterbirds at Qinghai Lake, China. Outbreaks have continued to periodically occur in wild birds at Qinghai Lake and elsewhere in Central China and Mongolia. This region has few poultry but is a major migration and breeding area for waterbirds in the Central Asian Flyway, although relatively little is known about migratory movements of different species and connectivity of their wetland habitats. The scientific debate has focused on the role of waterbirds in the epidemiology, maintenance and spread of HPAI H5N1: to what extent are they victims affected by the disease, or vectors that have a role in disease transmission? In this review, we summarise the current knowledge of wild bird involvement in the ecology of HPAI H5N1. Specifically, we present details on: (1) origin of HPAI H5N1; (2) waterbirds as LPAI reservoirs and evolution into HPAI; (3) the role of waterbirds in virus spread and persistence; (4) key biogeographic regions of outbreak; and (5) applying an ecological research perspective to studying AIVs in wild waterbirds and their ecosystems.
The female of Pellonyssus gorgasi Yunker and Radovsky, 1966 is redescribed and the male and protonymph are described for the first time. Previously known only from the unique holotype, P. gorgasi has a wide distribution through North, Central, and South America and occurs on diverse hummingbirds (Trochilidae). It is not known from any host outside that family. Records of P. gorgasi on hummingbird feeders and running onto the hand of a biologist feeding sugar solution to a young bird suggest that this mite uses flowers for transfer between hosts. This is the first indication that a mite in the family Macronyssidae may use a feeding substrate of a host for transfer beween hosts. Such behavior of a macronyssid species parasitic on hummingbirds is comparable to that of the non-parasitic flower mites in the family Ascidae that are phoretic on hummingbirds. Those studying the mites on flowers and hummingbirds in the latter family may encounter P. gorgasi. A key to females of the nine species in the genus Pellonyssus is given.
Varias fuentes de información sugieren que Pica nuttalli, un córvido endémico de California, es extremadamente susceptible al virus del oeste del Nilo (VON), y que su abundancia ha disminuido desde que el VON se estableció a través de California en 2004. Entre 2004 y 2006, 12,211 cadáveres de esta especie fueron reportados al departamento de servicios de salud de California. El 78% de los 1,007 cadáveres en los que se realizaron pruebas fueron VON-positivos, y ésta fue la mayor proporción de cadáveres VON-positivos entre todas las especies de aves de California que contaron con tamaños de muestra razonables (>20). Suponiendo que la población inicial era de 180,000 individuos en 2003, los datos del departamento de servicios de salud de California sugieren que las poblaciones de esta especie podrían haberse reducido en un 49% en sólo dos años. Los datos de los censos de aves reproductivas muestran un declive del 22% hasta 2005, y los del conteo navideño de aves un declive del 42% hasta 2006. Además, el tamaño de las bandadas observadas en tres sitios tradicionales de descanso comunal monitoreados en Sacramento, California, disminuyó dramáticamente después del establecimiento del VON, y dos de estos sitios quedaron vacíos para el verano de 2005 mientras que el tercero disminuyó precipitadamente hasta 2006. De 38 muestras serológicas de 21 individuos obtenidas en 2006 en Davis, California, sólo un individuo demostró producir anticuerpos específicos para el VON. Se requiere realizar un monitoreo a nivel de todo el ámbito de distribución de la especie para detectar y seguir sus tendencias poblacionales. El tamaño poblacional, la diversidad genética y su estructura poblacional, la mortalidad causada por factores específicos, y la viabilidad poblacional deben ser evaluados.
Infectious diseases are responsible for the extinction of a number of species. In conventional epidemic models, the transition from endemic population persistence to extirpation takes place gradually. However, if host demographics exhibits a strong Allee effect (AE) (population decline at low densities), extinction can occur abruptly in a catastrophic population crash. This might explain why species suddenly disappear even when they used to persist at high endemic population levels. Mathematically, the tipping point towards population collapse is associated with a saddle-node bifurcation. The underlying mechanism is the simultaneous population size depression and the increase of the extinction threshold due to parasite pathogenicity and Allee effect. Since highly pathogenic parasites cause their own extinction but not that of their host, there can be another saddle-node bifurcation with the re-emergence of two endemic equilibria. The implications for control interventions are discussed, suggesting that effective management may be possible for ℛ(0)≫1.
One group of commonly found parasites in birds, for which fitness consequences and effects on life history traits have been much debated are Haemosporidian blood parasites. In a long term study population of great reed warblers Acrocephalus arundinaceus in Sweden, previous studies have shown that the Haemosporidian blood parasites are in their chronic phase during the breeding season and that the fitness of infected and non-infected birds are similar. In the present study, we quantified parasite intensity (parasitemia) in 718 adults great reed warblers sampled between 1987 and 1998 for the three most common parasite species; Haemoproteus payevskyi (lineage GRW1), Plasmodium ashfordi (GRW2) and Plasmodium relictum (GRW4). We verified that the q-PCR method is accurately quantifying Haemoproteus payevskyi (GRW1) as it was highly correlated with the number of parasites seen under microscope. Frequency of mixed infections with two lineages was significantly higher than expected based on the prevalence of each of the three parasite lineages. The mean level of parasitemia was significantly different for the three lineages and individual birds had repeatable parasitemia levels between years. Females tended to have a higher parasitemia than males for all three parasite lineages combined. Females with higher GRW1 parasitemia tended to arrive later in spring to their breeding sites. There was a negative correlation between parasitemia and number of fledged offspring for GRW1, and a tendency for a negative correlation between GRW2 parasitemia and the proportion of recruiting offspring. Overall our results demonstrate that chronic Haemosporidian infections can have slight but significant effects on host life history traits, and therefore may act as important selective agents in wild bird populations.