Marcela M Uhart

• University of California, Davis

A small colony of black-browed albatrosses (Thalassarche melanophris, 21–65 breeding pairs) was discovered in 2003 on Albatross Islet, Tierra del Fuego, Chile. The formation of new breeding sites is important from an ecological and evolutionary perspective. This colony is particularly significant because it is the only one recorded for the species...

We report full-genome characterization of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus from an outbreak among sea lions (August 2023) in Argentina and possible spillover to fur seals and terns. Mammalian adaptation mutations in virus isolated from marine mammals and a human in Chile were detected in mammalian and avian hosts.

Hundreds of large whales have been tracked using consolidated (Type-C) satellite tags, yet there have been few studies on their impacts on whale health. In 2011, we initiated the first study designed to evaluate the effects of these tags in a baleen whale. Between 2011 and 2018, we tagged 79 North Atlantic humpback whales in the Gulf of Maine. We i...

Wildlife trafficking creates favorable scenarios for intra- and inter-specific interactions that can lead to parasite spread and disease emergence. Among the fauna affected by this activity, primates are relevant due to their potential to acquire and share zoonoses - infections caused by parasites that can spread between humans and other animals. T...

Trichinellosis is a foodborne disease caused by ingestion of raw or undercooked meat containing Trichinella spp. larvae. Consumption of wild boar (Sus scrofa) meat represents an important source of human trichinellosis worldwide. In El Palmar National Park (EPNP), Argentina, invasive alien wild boars are controlled and meat from culled animals is r...

‘Rewilding’ is a nature conservation strategy gaining prominence worldwide. Established in the Northern Hemisphere, rewilding initiatives have increasingly been proposed in Argentina, but their relative merits, feasibility of implementation and accountability have lacked adequate analysis and discussion. Recently, 125 scientists and practitioners w...

The hepatitis E virus (HEV) is an emergent zoonotic virus causing viral hepatitis worldwide. Clinically, hepatitis E is not easily distinguished from other types of acute viral hepatitis. There is a need for HEV diagnostic assays to detect and prevent interspecies transmission among susceptible populations. Nanobodies (Nbs) are expressed recombinan...

Highly pathogenic avian influenza (HPAI) A/H5N1 viruses (lineage 2.3.4.4b) are rapidly invading the Americas, threatening wildlife, poultry, and potentially evolving into the next global pandemic. In November 2022 HPAI arrived in Peru, triggering massive pelican and sea lion die-offs. We report genomic characterization of HPAI/H5N1 in five species...

Fibropapillomatosis (FP) is a disease characterized by epithelial tumors that can impede life-sustaining activities of sea turtles, especially green turtles (Chelonia mydas). FP is caused by a herpesvirus, but environmental factors are also thought to play a role in triggering FP tumor growth. In this study, we evaluate the epidemiology of FP tumor...

There is growing evidence of the threats that plastics pose to wildlife. Current knowledge of the negative effects of plastic debris on wildlife is largely based on consequences that are readily observed. However, other less visible effects such as toxicity derived from leaching of plastic additives remain less studied. Through a collaborative netw...

Microplastics (1-5mm) and macroplastics were detected in the esophagus-proventriculus-ventriculus of 11% of the seabirds analyzed in our study. 55% were males and all were juveniles.-Best-fitting generalized additive models (GAM) found associations between the transcript levels of AhR and UGT1 genes responding to bird age class, sex, mass, and plas...

En los últimos años se han desarrollado en Argentina distintas intervenciones relacionadas con el rewilding (o re-asilvestramiento), abarcando una variedad de especies (e.g., grandes carnívoros, ungulados, psitácidos) y ecorregiones (e.g., Chaco Húmedo y Seco, Estepa Patagónica). El reasilvestramiento es definido como una estrategia aplicada en el...

The hepatitis E virus (HEV) is an emergent zoonotic virus causing viral hepatitis worldwide. Clinically, hepatitis E is not easily distinguished from other types of acute viral hepatitis. There is a need for HEV diagnostic assays to detect and prevent interspecies transmission among susceptible populations. Nanobodies (Nbs) are expressed recombinan...

The migratory behaviors that characterize many marine species pose a challenge for the study of their demographic parameters and movement pat-terns due to the remoteness or seasonal inacces-sibility of their habitats (Witt et al., 2009). Photo-identification (hereafter photo-ID) is a non-invasive technique used to identify individuals by docu-menti...

Highly pathogenic avian influenza (HPAI) A/H5N1 viruses (lineage 2.3.4.4b) are rapidly invading the Americas, threatening wildlife, poultry, and potentially evolving into the next global pandemic. In November 2022, HPAI arrived in Peru, where massive pelican and sea lion die-offs are still underway. We report complete genomic characterization of HP...

The genus Caiman is one of the most taxonomically conflicted among crocodilians. Caiman crocodilus has four subspecies: Caiman crocodilus crocodilus, Caiman crocodilus fuscus, Caiman crocodilus chiapasius and Caiman crocodilus apaporiensis, but some studies recognize Caiman yacare as a subspecies of C. crocodilus or as a C. crocodilus–C. yacare com...

Plastic ingestion is a problem for seabirds worldwide. In addition to direct health effects such as obstruction or perforation of the gastrointestinal tract, plastic ingestion can also lead to indirect health effects through the release of chemicals that may be absorbed and cause systemic and chronic toxicity. Among chemicals that can be released b...

Health and diseases are integral parts of the life of seabirds that merit attention if we expect to truly understand, protect, and conserve them. Diseases such as avian influenza, avian pox, pasteurellosis, and paralytic shellfish poisoning have a proven history of decreasing the survival or breeding success of seabirds. However, each host-pathogen...

Hydatid disease is a neglected zoonotic parasitic disease caused by cysts of the tapeworm Echinococcus granulosus. Canids, especially domestic dogs, are definitive hosts of the parasite and are the most pragmatic targets for control programs. A governmental dog deworming campaign was established in 1979 to control hydatidosis in southern Chile, whi...

Wildlife trafficking creates favorable scenarios for intra- and inter-specific interactions that can lead to parasite spread and disease emergence. Among the fauna affected by this activity, primates are relevant due to their potential to acquire and share zoonotic infections. Though it is known that most primate parasites can affect multiple hosts...

La influenza aviar es una enfermedad aguda y altamente transmisible en aves domésticas y silvestres. Puede transmitirse también de aves a mamíferos, incluyendo a las personas. Los contagios a personas ocurren mayormente en contextos específicos de contacto muy estrecho y/o ambientes muy contaminados. Estos contagios a personas han ocurrido esporádi...

The family Chlamydiaceae is comprised of obligate intracellular bacteria, some of which are significant pathogens of humans and domestic animals. Magellanic penguins (Spheniscus magellanicus) are susceptible to Chlamydia psittaci outbreaks in captivity, and serological surveys detected antibodies against C. psittaci (or antigenically similar organi...

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using...

Wildlife health is an increasingly important component of the conservation of wild species. With human-induced global change, including biodiversity and habitat loss and degradation, wildlife is constantly subject to stressors that place it at an escalating risk of disease. This chapter provides a review of available information on the parasitic, v...

A recent review of the management of hyperabundant macropods in Aus-tralia proposed that expanded professional shooting is likely to lead to better biodiversity and animal welfare outcomes. While the tenets of this general argument are sound, it overlooks one important issue for biodiversity and animal health and welfare: reliance on toxic lead-bas...

Amazonian countries have historically sourced the international wildlife trade. However, little is known about their domestic trade, which is often overlooked in estimates of trafficking. Peruvian law prohibits the unauthorized trade and possession of wildlife, but illegal sales are common in urban markets. To describe the dynamics, diversity, and...

The cost of reproduction greatly affects a species’ life history strategy. Baleen whales exhibit some of the fastest offspring growth rates in the animal kingdom. We quantified the energetic cost of gestation for southern right whales (Eubalaena australis) by combining whaling catch records of pregnant females with photogrammetry data on southern r...

Sarcoptic mange epidemics can devastate wildlife populations. In 2014, mange was first detected in vicuñas (Vicugna vicugna) and guanacos (Lama guanicoe) in San Guillermo National Park (SGNP), Argentina. This study describes the temporal dynamics of the outbreak, its effects on the park’s wild camelid populations between 2017–2019, and investigates...

Climate change has exacerbated the frequency and severity of heat waves, which on occasion lead to mass mortalities. Here, we report a massive mortality event in Imperial Cormorant Leucocarbo atriceps chicks that took place during December 2016 at Punta León, one of the two largest colonies (> 6000 pairs) and the northernmost colony for the species...

In waters off Península Valdés (PV), Argentina, southern right whales (SRW, Eubalaena australis) are occasionally exposed to domoic acid (DA), a neurotoxin produced by diatoms of the genus Pseudo-nitzschia. Domoic acid toxicity in marine mammals can cause gastrointestinal and neurological clinical signs, alterations in hematologic and endocrine var...

A presença de resíduos antropogênicos em águas oceânicas e sua ingestão por aves marinhas tem sido alvo de um crescente número de estudos. Os Procellariiformes são particularmente suscetíveis à ingestão de plástico, uma vez que se alimentam preferencialmente de pequenas presas na superfície da água, onde os plásticos tendem a flutuar e se acumular....

Although the ingestion of plastics and other anthropogenic debris by seabirds is a global problem, few studies have employed standardized protocols to quantify and classify the debris ingested by seabirds in the Southwest Atlantic. We evaluated the ingestion of marine debris (items >0.1 mm) by 126 coastal and pelagic birds (19 species) along the co...

This is the first field study to evaluate lead exposure in dogs fed game meat and offal and, to our knowledge, the first study exploring associations between game consumption and dog health status. We quantified lead concentrations in blood and hair and haematological parameters of 31 dogs fed game meat and offal from wild boar (Sus scrofa) and axi...

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host range and estimate pathways for potential human infection. Using...

Sarcoptic mange epidemics can devastate wildlife populations. In 2014, mange was first detected in vicuña ( Vicugna vicugna ) and guanaco ( Lama guanicoe ) in San Guillermo National Park (SGNP), Argentina. This study characterized the potential source and the impacts of the outbreak in 2017–2019. Transect surveys indicated a sharp decrease in the d...

Consumption of meat from animals hunted with Pb ammunition can cause toxic accumulation with consequent health risks, even if relatively small amounts are consumed in each exposure. In El Palmar National Park, Argentina, invasive alien mammals, wild boar (Sus scrofa) and axis deer (Axis axis), are culled with Pb ammunition and their meat is consume...

Kelp gulls Larus dominicanus (KG) feed on the skin and blubber of living southern right whales Eubalaena australis (SRWs) off Península Valdés (PV), Argentina. The whales respond strongly to KG micropredation by changing their immediate (acute) behavior during attacks and their overall (chronic) surfacing pattern and body posture to minimize gull e...

Marine mammals rely on blubber mainly for energy storage, buoyancy, and streamlining. Mysticetes are born with a relatively thin fat layer that grows rapidly during nursing. However, little information on blubber deposition patterns is available for baleen whale calves. We measured blubber thickness at nine body locations in 350 southern right whal...

Objective: To describe and quantify the extent of wildlife and environment sector inclusion in country evaluation and prioritization tools for health security, and to provide practical recommendations for global and national action to improve pandemic prevention and preparedness. Methods: To assess coverage of wildlife and other environmental as...

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response,...

Obtaining endocrine data from alternative sample types such as baleen and other keratinized tissues has proven a valuable tool to investigate reproductive and stress physiology via steroid hormone quantification, and metabolic stress via thyroid hormone quantification in whales and other vertebrates. These alternative sample types provide an integr...

Las enfermedades infecciosas emergentes que derivan en pandemias se están volviendo recurrentes, con graves consecuencias que exceden nuestra salud y bienestar. Aunque de inusitada magnitud, la pandemia de COVID-19 es solo una más en una larga lista de eventos severos que han impactado a la humanidad en las últimas décadas (HIV-SIDA, Ébola, Nipah,...

Over one hundred cases of human rickettsiosis, many fatal, are reported annually across the US-Mexico transboundary region, representing a likely undercount. Although cases are often attributed to Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, multiple other Rickettsia pathogens are present in North America. We conducted multiple...

Over the past fifty years, interactions between anthropogenic debris and a wide range of marine species have increased. In cetaceans, the most frequent interactions have occurred through ingestion and/or entanglement, with results ranging from minor injuries to death in affected animals. While debris ingestion is widely documented in odontocetes, r...

Wildlife health is widely under-developed in the design, resourcing, and operations of national biodiversity and health programs. Capacity building, efforts to fill knowledge gaps, and surveillance programs are urgently needed at country and regional levels. Global efforts are needed to provide essential stop-gaps to support countries and provide r...

Over the past fifty years, interactions between anthropogenic debris and a wide range of marine species have increased. In cetaceans, the most frequent interactions have occurred through ingestion and/or entanglement, with results ranging from minor injuries to death in affected animals. While debris ingestion is widely documented in odontocetes, r...

The IPBES Bureau and Multidisciplinary Expert Panel, in the context of the extraordinary situation caused by the COVID-19 pandemic, and considering the role that IPBES can play in strengthening the knowledge base on biodiversity, decided that IPBES would organize a “Platform workshop” on biodiversity and pandemics, in accordance with the procedures...

Disease is an increasingly recognised threat to wild animal populations and the conservation of endangered species. The World Organisation for Animal Health (OIE) Worldwide Monitoring System for Wild Animal Diseases (WAHIS–Wild) serves as the main global information portal for wildlife disease events, compiled via voluntary reporting by countries o...

Sarcoptic mange has been anecdotally reported in Chilean wildlife during the last decade. Although this disease can have devastating outcomes for biodiversity, there is no comprehensive assessment of this potential threat in Chile. Because the current capacity to monitor sarcoptic mange and other wildlife diseases is limited in this country, we use...

Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whale Eubalaena australis population that calves off Península Valdés, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous stud...

Background In 2007–2009, a major yellow fever virus (YFV) outbreak in Northern Argentina decimated the local howler monkey (Alouatta) population. Aims To evaluate whether the surviving howler monkeys possess advantageous genetic variants inherited from monkeys alive prior to the YFV outbreak, we explored the relationship between Toll‐like receptor...

Poaching and trade of wildlife for local and international exotic pet markets result in frequent close contact between human and non-human primates (NHP). This forced sympatry, coupled with the phylogenetic proximity of humans and NHPs, provides multiple new opportunities for disease emergence. Limited information is available about the presence of...

Physiological measurements are informative in assessing the relative importance of stressors that potentially impact the health of wildlife. Kelp Gulls, Larus dominicanus (KG), resident to the region of Península Valdés, Argentina, have developed a unique behavior of landing on the backs of southern right whale adults and calves, Eubalaena australi...

The North Atlantic right whale Eubalaena glacialis (NARW), currently numbering <410 individuals, is on a trajectory to extinction. Although direct mortality from ship strikes and fishing gear entanglements remain the major threats to the population, reproductive failure, resulting from poor body condition and sublethal chronic entanglement stress,...

Sarcoptic mange has been anecdotally reported in Chilean wildlife during the last decade. Although this disease can have devastating outcomes for biodiversity, there is no comprehensive assessment of this potential threat in Chile. Because the current capacity to monitor sarcoptic mange and other wildlife diseases is limited in this country, we use...

This is the color version of Figure 2 as presented in the main text.

Recurring outbreaks of emerging and re-emerging zoonoses, such as Ebola virus disease, avian influenza, and Nipah virus, serve as a reminder that the health of humans, animals, and the environment are interconnected and that early response to emerging zoonotic pathogens requires a coordinated, interdisciplinary, cross-sectoral approach. As our worl...

Recurring outbreaks of emerging and re-emerging zoonoses, such as Ebola virus disease, avian influenza, and Nipah virus, serve as a reminder that the health of humans, animals, and the environment are interconnected and that early response to emerging zoonotic pathogens requires a coordinated, interdisciplinary, cross-sectoral approach. As our worl...

Animal-borne electronic instruments (tags) are valuable tools for collecting information on cetacean physiology, behaviour and ecology, and for enhancing conservation and management policies for cetacean populations. Tags allow researchers to track the movement patterns, habitat use and other aspects of the behaviour of animals that are otherwise d...

Body mass is a key life‐history trait in animals. Despite being the largest animals on the planet, no method currently exists to estimate body mass of free‐living whales. We combined aerial photographs and historical catch records to estimate the body mass of free‐living right whales ( Eubalaena sp.). First, aerial photogrammetry from unmanned aeri...

In 2007-2009, a major yellow fever virus (YFV) outbreak in Northern Argentina decimated the local howler monkey (Alouatta) population. We explored the relationship between Toll-like receptor (TLR) 7 and TLR8 gene variation and YFV susceptibility using samples from Alouatta individuals alive before the YFV outbreak, individuals that died during the...

Despite being the most numerous penguin species in South America, exposure of the Magellanic Penguin (Spheniscus magellanicus) to pathogens has not yet been thoroughly assessed. We collected serum from 1,058 Magellanic Penguins at 10 breeding colonies along the entire latitudinal range of this species in Argentina. The work spanned 10 breeding seas...

We report on the investigation of a mass stranding of 68 short-beaked common dolphins (Delphinus delphis) that occurred in Golfo Nuevo, Península Valdés, Argentina in March 2018. Twenty-one of the stranded dolphins were returned alive to the sea, while 47 animals died. Dead dolphins included all ages, with more males than females (29 males and 18 f...

The huemul (Hippocamelus bisulcus) is an endangered cervid endemic to southern Argentina and Chile. Here we report foot lesions in 24 huemul from Bernardo O’Higgins National Park, Chile, between 2005 and 2010. Affected deer displayed variably severe clinical signs, including lameness and soft tissue swelling of the limbs proximal to the hoof or in...

Waterfowl hunting in Argentina is a profitable industry that attracts hunters from all over the world. Most hunting occurs as high-end hunting tourism, through which registered outfitters service predominantly foreign clients on private lands. Lead pollution from hunting ammunition is increasingly recognized as a significant local problem, impactin...

Blood parameters (hematology and biochemistry) are useful in assessing the physiological, nutritional, and overall health status of both captive and free-ranging wildlife. In this study, we established baseline values for blood parameters (hematology, plasma biochemistry, and trace elements) of free-ranging adult Magellanic Penguins (Spheniscus mag...

Between 2003 and 2017, at least 706 southern right whale (Eubalaena australis) calves died at the Península Valdes calving ground in Argentina. Pathogenic microbes are often suggested to be the cause of stranding events in cetaceans; however, to date there is no evidence supporting bacterial infections as a leading cause of right whale calf deaths...

El Plan de Control de Mamíferos Exóticos Invasores (PCMEI) del PN El Palmar, implementado desde 2006, es un ejemplo en Latinoamérica en su objetivo de disminuir las poblaciones de jabalí (Sus scrofa) y ciervo axis (Axis axis) en favor de la biodiversidad nativa. Desde su inicio, dicho plan promueve el aprovechamiento de las especies controladas, po...

Wildlife health is important for conservation, healthy ecosystems, sustainable development and biosecurity. It presents unique challenges for national programme governance and delivery because wildlife health not only crosses jurisdictional responsibilities and authorities but also inherently spans multiple sectors of expertise. The World Organisat...

Baleen tissue accumulates stress hormones (glucocorticoids, GC) as it grows, along with other adrenal, gonadal and thyroid hormones. The hormones are deposited in a linear fashion such that a single plate of baleen allows retrospective assessment and evaluation of long-term trends in the whales' physiological condition. In whale calves, a single pi...

Lead contamination is a worldwide problem that affects the health of several bird species and can cause biodiversity loss. However, in South America there is little information about this problem and the species affected. The aim of this study is to compile existing knowledge about lead contamination in South American bird species and propose actio...

Caves provide critical roosting habitats for bats globally, but are increasingly disturbed or destroyed by human activities such as tourism and extractive industries. In addition to degrading the habitats of cave-roosting bats, such activities often promote contact between humans and bats, which may have potential impacts on human health. Cave-roos...

Plasma biochemistries provide a complementary method for assessing physiological and nutritional status of free-ranging wild birds. Triglycerides, total protein and alkaline phosphatase were determined in 110 free-living Imperial Cormorant (Phalacrocorax atriceps) chicks aged 16-35 days, at Punta León (Argentina) during 2010 and 2011. Body mass at...

Different herpesviruses have been associated with respiratory and enteric disease and mortality among seabirds and waterfowl. In 2011, a respiratory disease outbreak affected 58.3% (98/168) of the Magellanic penguins undergoing rehabilitation due to an oil spill off the southern Brazilian coast. Etiology was attributed to a novel herpesvirus identi...

Albatrosses ( Diomedeidae ) and large petrels ( Macronectes and Procellaria spp.) are among the world’s most rapidly declining birds. Some of the most endangered species, Amsterdam Albatross Diomedea amsterdamensis, Indian Yellow-nosed Albatross Thalassarche carteri and Sooty Albatross Phoebetria fusca , are at risk from recurrent avian cholera out...

Magellanic penguins (Spheniscus magellanicus) are native to Argentina, Chile and the Falkland Islands. Magellanic penguins are highly susceptible to blood parasites such as the mosquito-borne Plasmodium spp., which have been documented causing high morbidity and mortality in zoos and rehabilitation centres. However, to date no blood parasites have...

Seabirds are amongst the most globally-threatened of all groups of birds, and conservation issues specific to albatrosses (Diomedeidae) and large petrels (Procellaria spp. and giant petrels Macronectes spp.) led to drafting of the multi-lateral Agreement on the Conservation of Albatrosses and Petrels (ACAP). Here we review the taxonomy, breeding an...

Satellite transmitters were attached to seven southern right whales (Eubalaena australis) in their breeding grounds in Golfo Nuevo, Península Valdés, Argentina, to monitor their movements and migration towards feeding destinations. Fifteen integrated transdermal implanted tags were deployed in juvenile and adult whales. Tag duration varied between...

Between 2003 and 2012, 605 southern right whales (SRW; Eubalaena australis) were found dead along the shores of Península Valdés (PV), Argentina. These deaths included alarmingly high annual losses between 2007 and 2012, a peak number of deaths (116) in 2012, and a significant number of deaths across years in calves-of-the-year (544 of 605 [89.9%];...

The pollution of wetlands by lead derived from waterfowl hunting with lead shot was investigated. We determined soil pellet density and Pb concentration in soil, water and vegetation in natural wetlands and rice fields in central-eastern Santa Fe province, Argentina. Pellet density varied greatly among hunting sites (between 5.5-141 pellets/m(2)) a...

Leptospirosis is the most widespread zoonotic disease in the world. It is caused by pathogenic spirochetes of the genus Leptospira spp. and is maintained in nature through chronic renal infection of carrier animals. Rodents and other small mammals are the main reservoirs. Information on leptospirosis in marine mammals is scarce; however, cases of l...

At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequen...