Luis Sandoval

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Verified

Luis verified their affiliation via an institutional email.

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• Ph.D.
• Investigator, Professor at University of Costa Rica

The likelihood of hybridization after secondary contact is reduced when assortative mating is strong and fitness of hybrids is low; thus, maintaining reproductive isolation. To this end, signals that convey population identity may enhance recognition and reduce hybridization by promoting assortative mating. Here, we studied visual and acoustic sign...

Research on avian bioacoustics in the Neotropics has surged over the last several decades due to increased interest in the large diversity of vocal behaviors and vocalization and the broader accessibility of recording equipment and software. Here, we present a synthesis of the current and past knowledge of Neotropical bird bioacoustics. This synthe...

Bird vocalizations have been split historically into two main categories: calls and songs. This categorization has been based mainly on the duration and complexity of the vocalization, although other criteria including function, development, and phylogeny have been included to separate both vocalizations. The increasing number of studies over the l...

In animal acoustic communication is necessary that signals arrive to the receiver with reduced degradation and attenuation for a better transmission of the message. The noise pollution resulting from anthropogenic activities in cities reduces efficiency and efficacy of acoustic communication. Some species respond to high levels of noise increasing...

Urbanization has reshaped the distribution of biodiversity on Earth, but we are only beginning to understand its effects on ecological communities. While urbanization may have homogenization effects strong enough to blur the large-scale patterns in interaction networks, urban community patterns may still be associated with climate gradients reflect...

We provide the first description of the nest of Sulphur-rumped Tanager Heterospingus rubrifrons, which was found at Veragua Rainforest Reserve, Limón province, Costa Rica, in June 2023. The nest was sited atop the base of a palm frond, 5 m above ground, and consisted of two layers of different material and a ‘tail’, similar to the nests of closely...

Agriculture, which is spreading rapidly, is one of the major effectors on biodiversity – generally contributing to its decline. In the past few decades, most research efforts have focused on the impact of industrial agriculture on the environment and biodiversity. However, less attention has been paid on examining the impact of sustainable agricult...

Urbanization alters ecosystems, fragmenting natural habitats, and hence, increasing isolation between populations. Therefore, a reduction in gene flow among isolated populations is expected with greater distance and time since fragmentation. Changes in the structure, density, or community composition in the remaining habitats often result in specie...

Golfo Dulce is a fjord-like embayment on the southern Pacific coast of Costa Rica, which encompasses the marine protected area of Piedras Blancas National Park. The gulf is surrounded by mangroves, rocky shores, and sandy beaches that are home to migratory and resident bird species. Here, we provide a checklist of 73 marine birds, including records...

Males of the Strawberry Poison Frog (Oophaga pumilio) use acoustic signals during courtship and territorial interactions. In these contexts, spectro-temporal characteristics of the calls provide information on body size, territory quality, and dominance to conspecifics. Previous research on this species has associated low-rate territorial calls pro...

After establishing secondary contact, recently diverged populations may remain reproductively isolated or may hybridize to a varying extent depending on factors such as hybrid fitness and the strength of assortative mating. Here, we used genomic and phenotypic data from three independent contact zones between subspecies of the Variable Seedeater (S...

Urban bird dwellers survive and reproduce in highly urbanized ecosystems. Some individuals adjust to these novel conditions by changing natural nesting materials for artificial materials, thus making nests more conspicuous in the environment. The consequences of using artificial materials for nesting remain poorly understood, especially from a nest...

This collection contains 34 hour-long soundscape recordings, which have been annotated by expert ornithologists who provided 6,952 bounding box labels for 89 different bird species from Colombia and Costa Rica. The data were recorded in 2019 at two highly diverse neotropical coffee farm landscapes from the towns of Jardín, Colombia and San Ramon, C...

We report the first record of Lesson’s Seedeater Sporophila bouvronides, a South American species, in Costa Rica. It was seen at Tortuguero, in the lowlands of north-east Costa Rica in June 2022. The record is perhaps explained by the passage of a tropical storm that moved north-west from off northern South America.

After establishing secondary contact, recently diverged populations may remain reproductively isolated or hybridize to a varying extent depending on factors such as hybrid fitness and the strength of assortative mating. Replicated contact zones between hybridizing taxa offer a unique opportunity to explore how different factors interact to shape pa...

Disentangling the evolutionary relationships of rapidly radiating clades is often challenging because of low genetic differentiation and potentially high levels of gene flow among diverging taxa. The genus Sporophila consists of small Neotropical birds that show, in general, relatively low genetic divergence, but particularly high speciation rates...

A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special dossier, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting...

Many animals respond to heterospecific signals that indicate the presence of food or predators. Although the benefits of responding are clear, the behavioral and cognitive mechanisms underlying responses are not. Whether responses are learned, innate, or an epiphenomenon created by following other species as they respond to signals remains unknown...

Gene flow in birds can be affected by urbanization depending on natural history traits and adaptability to habitat change. Contrasting results can be expected when comparing species with opposite resilience to urbanization. In this study, we assessed genetic diversity and structure for two bird species, the urban avoider white-eared ground-sparrow,...

To avoid unnecessary energy expenditures in territorial defense, many species (e.g., insects, amphibians, birds, and mammals) have developed the capability to distinguish between different intruder types using visual, acoustic, and/or chemical signals. Determining the mechanism used for intruder recognition is key to understanding the dynamics of t...

Anthropogenic noise can create an acoustic environment detrimental for animals that communicate using acoustic signals. Currently, most studies of noise and wildlife come from traffic noise in cities. Less is known about the effects of noise created by industry in natural areas. Songbirds far from cities, but influenced by industry, could be affect...

Urbanization is one of the main problems for biodiversity around the world, associated with a decrease of natural habitats and its resources. In contrast, urbanization can also provide new resources that could be used by species that thrive in cities. Understanding why this happens is basic to understand species adaptation to urban areas. Here, we...

Urban development reduces the abundance of most natural resources for some birds but also provides new opportunities for others. One group that is more likely affected by urban development is the cavity-nesting species (primary excavators and cavity-adopters), because the main substrates used for nesting, such as dead trees or dirt banks, are frequ...

Behavior is often phylogenetically informative and detailed descriptions of behavior have been used to support taxonomic relationships in several groups, such as birds, lizards, and arthropods. Web building behavior has provided informative traits to several spider families, but observations are lacking for other families, such as wall spiders Oeco...

Urban expansion has been identified as one of the main threats to biodiversity because it can negatively affect wildlife populations. However, wildlife population dynamics have not been studied in one of the most rapidly urbanizing regions in the world—the Neotropics. To examine the effect of urbanization on the population dynamics of Neotropical w...

Worldwide urban expansion threatens biodiversity inhabiting the original natural environments now being transformed, especially range-restricted species. Here, we provide estimates of population density, population size, and territory size of Cabanis’s Ground Sparrow Melozone cabanisi, a Costa Rican endemic. Additionally, we provide information abo...

Gene flow in birds can be affected by urbanization depending on natural history traits and adaptability to habitat change. Contrasting results can be expected when comparing species with opposite resilience to urbanization. In this study, we assessed genetic diversity and structure for two bird species, the urban avoider white-eared ground-sparrow,...

Studies on the impact of human activity on animal behaviour are critical for understanding the extent to which humans affect ecological dynamics. Previous studies have found that human presence alters antipredator behaviours, which can be measured by flight initiation distance (FID). We investigated escape behaviour of 96 black iguanas ( Ctenosaura...

The expansion of human settlements has produced significant changes in natural ecosystems by fragmenting and reducing their area. Those changes influence the availability of natural and artificial sites used to build nests by birds. Some species nest on perches built by humans, but the characteristics of the perches that are selected are unknown. O...

The internal temperature of nests largely depends on the materials used in their construction because the characteristics of each material affect the isolation of nest walls. In urban environments, the availability of natural materials for nest building decreases, while the availability of artificial materials increases. Therefore, many urban bird...

Many groups of vertebrates produce distress calls when attacked by predators as a last attempt to survive. However, few studies investigate whether recognition of distress calls involves learning or acoustic similarity to familiar calls. This study assesses the importance of these two factors as well as phylogenetic relatedness in distress call rec...

Noise affects the recognition of acoustic signals by masking information. To compensate for increased noise, individuals often increase the minimum frequency of their vocalization to reduce noise interference. Our goal was to analyze the effect of noise on the characteristics of different bird vocalizations, through a comparative study of vocalizat...

The western and trans-Andean populations of Striped Woodhaunter Automolus subulatus are sometimes considered separate species. We discuss previously published data on the nesting of Striped Woodhaunter and present novel information concerning the nest, eggs, nestlings and parental care of western A. s virgatus and trans-Andean A. s. subulatus. Nest...

Introduction: Migration of people from rural environments to cities has accelerated urbanization and modified the landscape as well as the ecological processes and communities in these areas. The Costa Rican endemic Cabanis´s Ground-Sparrow (Melozone cabanisi) is a species of limited distribution restricted to the “Gran Area Metropolitana”, which i...

Strawberry Poison Frogs (Oophaga pumilio) are common members of leaf litter lowland communities in Central America and exhibit several color morphs throughout their distribution. Color plays a determinant role during intra-and intermorph interactions in many insular populations, but little is known about the variation and perception of visual signa...

Acoustic signals are distorted by vegetation, wind currents, or other sounds when transmitted through the environment. Consequently, vocalizations with features that optimize sound transmission or behaviors that improve the efficacy of communication have evolved in many animal species. Among behavioral strategies, some species call from perches abo...

Animals endemic to tropical mountains are known to be especially vulnerable to climate change. The Cordillera de Talamanca (Costa Rica and Panama) is a geographically isolated mountain chain and global biodiversity hotspot, home to more than 50 endemic bird species. We used eBird community science observations to predict the distributions of a suit...

Anthropogenic noise (≤ 3 kHz) can affect key features of birds’ acoustic communication via two different processes: (1) song‐learning, because songbirds need to hear themselves and other birds to crystallize their song, and (2) avoidance of song elements that overlap with anthropogenic noise. In this study we tested whether anthropogenic noise redu...

Background Urban expansion has been identified as one of the leading drivers of biodiversity change or loss. For birds, urbanization is specifically related to survival, breeding success, and territory size. Understanding how different birds adjust territory size in response to urbanization is essential for their conservation in urban environments...

Acoustic signals used in animal communication play a key role in mate attraction, species recognition, and territory defense. Variation in acoustic signals may reflect population structure, lack of gene flow, and phylogenetic relationships. In birds, the study of geographic variation in acoustic signals has been useful for elucidating potential fac...

Territorial defence and maintaining contact are two hypotheses of duet functions. Nevertheless, the acoustic characteristics of duets in these contexts have been poorly quantified. This work aimed to compare the spectrotemporal characteristics and synchronisation in White-eared Ground-sparrow duets produced in aggressive context (i.e. territorial d...

Black plumage is expected to absorb and retain more heat and provide better protection against UV radiation compared with lighter plumages. Black plumage is common in species of the genera Turdus and Platycichla that inhabit highlands across different regions of the world. Considering this geographical recurrent pattern we tested the hypothesis tha...

Los mosaicos agrícolas han sido estudiados para comprender como contribuyen a mantener la riqueza de las especies según el tipo de matriz. Sin embargo, el estudio de la fenología de las especies dentro de estos ambientes ha sido dejado de lado. Por lo tanto mi objetivo con esta investigación fue analizar los cambios en la riqueza y abundancia de la...

Woodpeckers nesting substrate abundance may be reduced by urban expansion, negatively affecting their reproduction. Long-term studies in the tropics are rare but valuable to estimate how urban development has affected ecological communities. We present a ten-year comparison on nesting substrate abundance and their use by Melanerpes rubricapillus an...

Las señales acústicas producidas por animales pueden ser enmascaradas por el ruido del medio ambiente en que se encuentran, tanto de origen natural como antropogénico. Una especie que puede ver afectada su comunicación por el ruido medio ambiental es la rana de vidrio Hyalinobatrachium fleischmanni (Centrolenidae), porque la distribución actual de...

Conservation efforts in terrestrial environments have focused on preserving patches of natural habitats and restoring disturbed habitats, with the main goal of transforming them into forests or habitats that resemble the original conditions. This approach tends to overlook the importance of conserving early succes-sional vegetation (e.g., riverside...

El Niño and La Niña climatic oscillations have dramatic effects on population dynamics and community structure of different animals. For marine birds, El Niño phenomenon drastically increases their mortality and reduces their reproductive success. In terrestrial ecosystems, the lack of long-term longitudinal data limits our understanding of the imp...

Los factores biomecánicos, el comportamiento e historia natural de las especies pueden influenciar la forma y dimensión del ala en las aves. Por lo tanto, la morfología de las alas de cada especie podría estar adaptada al ambiente en el que habitan. En palomas (familia Columbidae) existe un gradiente de especies que tienden a volar mucho y otras qu...

Feeding events of unsual prey items are rarely recorded in the field. Here we report diet resources for eleven Neotropical bird species. We include an observation of scavenging behavior for the Black Hawk-Eagle (Spizaetus tyrannus), the first record of wood consumption by the Crimson-fronted Parakeet (Psittacara finschi), moss consumption by the Me...

Background Duet function hypotheses have been mostly studied in bird species that produce duets with male and female solo songs. However, in order to understand if patterns of duet function are similar across all duetting species, it is highly necessary to test the duet function hypotheses in species that produce duets with vocalizations other than...

· What little we know of the breeding biology of Selenidera toucanets comes from only two of the eight species. For most species the breeding season is approximated through indirect evidence (e.g., gonad size in collected specimens and juvenile observation), but few nests have been found. Here, we describe nest architecture, parental care behavior,...

Neotropical bird records committees have been growing in numbers, remit and prominence in recent years. This feature-by members of those committees-explains how and why committees were established and encourages birders to submit their observations directly to committees as well as sharing through other means.

Information theory and its indices were developed for human communication to predict the amount of information transferred in a message. One such index, the Shannon-Weiner index (SWI), has often been used to analyse information from other fields in which its application may not be appropriate. In ecoacoustics, SWI is used to compare acoustic divers...

We present new distribution information for 19 species of Costa Rican birds. Thirteen species show changes in altitudinal distribution, 9 are recorded at higher elevations such as Egretta rufescens (Gmelin, 1789), Heliomaster con-stantii (Delattre, 1843), Myiozetetes cayanensis (Linnaeus, 1766), and Lonchura malacca (Linnaeus, 1766), and 4 are reco...

Many species use low-amplitude (soft) song during close range interactions with conspecifics, such as in aggressive encounters or courtship displays. It has been suggested that soft song is adapted to limit eavesdropping by conspecifics or predators through reduced signal transmission range. If so, other structural features of soft song, besides am...

We provide the first description of nest architecture and composition, adult construction behavior, and egg characteristics for the genus Rhytipterna. We provide these data for a nest of the Rufous Mourner (Rhytipterna h. holerythra) found under construction and followed through clutch completion and subsequent failure at La Selva Biological Statio...

The taxonomy of the genus Melozone has recently been analyzed from genus to subspecies level, leading to a significant revision of our understanding of this group of birds. Previous studies quantified differences in phenotypic traits, behavior, and genotypes, to provide a better understanding of the underappreciated diversity within Melozone and th...

The hosts and cocoon webs of koinobiont-ectoparasitic wasps in the genus Eruga Townes in Townes & Townes, 1960 are known for only two species. We describe here the host spider and cocoon web of a third Eruga species: E.Telljohanni Gauld, 1991. This wasp parasitizes Leucauge White, 1841 species, which are induced to construct a highly modified cocoo...

Different mechanisms have been proposed for encoding information into vocalizations: variation of frequency or temporal characteristics, variation in the rate of vocalization production, and use of different vocalization types. We analyze the effect of rate variation on the dual function of chip calls (contact and alarm) produced by White-eared Gro...

When vocalizations transmit throughout the environment, attenuation and degradation may change the information of the signal; the loss of information is related to changes in both frequency and duration of vocalizations. The variation in frequency and duration of bird calls is related to the functions of each call type. Using a sound transmission e...

Isla del Coco is one of the five oceanic islands situated on the eastern tropical Pacific Ocean and represents an important nesting and roosting site for seabirds. Despite several factors that can potentially impact its seabird fauna, knowledge about species density and distribution as well as of the size of its breeding colony is limited, currentl...

http://www.marineornithology.org/PDF/44_2/44_2_167-169.pdf

Many animals produce complex vocalizations that show pronounced variation between populations. The Acoustic Adaptation Hypothesis helps to explain this variation, suggesting that acoustic signals are optimized for transmission through different environments. Little is known about the transmission properties of female vocalizations because most stud...

Tres nidos de la Cotinga Nivosa Carpodectes nitidus muestran un diseño muy simple, que consiste en una plataforma construida de ramitas y zarcillos, similar al descrito previamente para esta especie y para otras cotingas. La alimentación del pichón (en uno de los nidos) consiste en artrópodos, ranas y frutos, con una mayor proporción de dieta anima...

The breeding biology of the genus Discosura (Trochilidae) is poorly known. Here, we describe in detail the nest and eggs of the Green Thorntail (D. conversii). We analyze two nests; one was collected with two eggs at Limón province, Costa Rica, the other was observed and photographed at Departamento de Antioquia, Colombia. The eggs are white and ov...

The Acoustic Adaptation Hypothesis posits that habitat characteristics influence the structure of animal vocalizations and that animals will vocalize and display behaviours optimized for sound transmission. White-eared ground-sparrows Melozone leucotis live in habitats with dense vegetation where vocal communication is an ideal mode of communicatio...

Sound production in lepidopteran adults has been reported in at least 13 families. The majority of these families produce ultrasonic sounds that are inaudible to humans. Here we report the first record of an audible sound produced by a Phassus sp. (Hepialidae) from Costa Rica. The sound is clicking or creaking-like, produced as the moth raises its...

There are relatively few quantitative descriptive studies of the vocalisations and vocal behaviour of tropical bird species, in spite of the tropic’s rich avian biodiversity and the extensive variety of vocalisations produced by tropical birds. This lack of information inhibits our understanding of tropical animals, including our ability to perform...

The interaction among natural selection, sexual selection, and species-specific ecological requirements is responsible for the evolution of complex courtship behaviors and breeding strategies. In some anurans, the breeding season is restricted to a short period each year (explosive breeders). Rhinophrynus dorsalis is a species with one of the short...

Gray-bellied Hawk (Accipiter poliogaster) is a diur-nal raptor with a distribution range and movements poorly known. A juvenile was recorded in Costa Rica in 2008 and 2009 for in the Caribbean lowlands. In this note we reported the first adult observation for Costa Rica and a new locality. Even though is uncertain how this species of bird was able...

Melozone biarcuata (Prevost's Ground-sparrow) has traditionally been divided into two allopatric groups based on differences in vocalizations and plumage characteristics: M. b. cabanisi in Costa Rica and M. b. biarcuata/M. b. hartwegi in northern Central America. However, the relationship between these subspecies has not been studied using a modern...

Many species of sparrows (Emberizidae) in the temperate zone provide model systems for understanding bird song and singing behaviour. In contrast, the vocal repertoire and vocal behaviour for most tropical sparrows is poorly understood, in spite of their impressive biodiversity. We present here the first detailed quantitative description of vocal r...

We present information about the relative abundance and occurrence of the Redhead (Aythya americana), and the Ruddy Duck (Oxyura jamaicensis) in Costa Rica. The observations were conducted during the winter seasons of 2010 to 2011, 2011 to 2012, and 2012 to 2013 at different wetlands across the country. These sightings represent the southernmost re...

Communication between social animals is often more effective when signals facilitate individual recognition. Two critical requirements for individual recognition are the occurrence of characteristics that are unique to each individual, and the consistency of these characteristics through time. In some animals, characteristics of acoustic signals ar...

Coloration of the egg sacs of spiders varies widely to the human eye, both across and within taxonomic groups. These differences in coloration are expected with differences in the biology and ecology of different species. Here we measure the spectral properties of the egg sacs of 15 species in six families. Ultraviolet chroma, red chroma, and parti...

The natural history of many tropical bird species is poorly described, preventing more detailed studies of ecology, behavior, and evolution. For most sexually monochromatic tropical bird species, we lack field methodologies to categorize the sex of adults. In this study, we describe sex-based morphological differences of three monochromatic species...

Urban habitats are noisy and constrain acoustic communication in birds. We analysed the effect of anthropogenic noise on the vocalization characteristics of House Wrens Troglodytes aedon at two sites with different noise levels (rural and urban). We measured in each song and song trill the frequency bandwidth, maximum amplitude, highest and minimum...

Efficient communication between animals requires specificity to ensure that animals distinguish relevant signals from background noise. Research on discrimination between the acoustic signals of heterospecific versus conspecific animals, especially in birds, has focused on the songs produced by breeding males, in spite of the fact that animals prod...