Meet our grantees
Wild Animal Initiative funds academic research on high-priority questions in wild animal welfare.
The goal of our grants program is to fund research that deepens scientific knowledge of the welfare of wild animals in order to better understand how to improve the welfare of as many wild animals as possible, regardless of what causes the threats to their well-being.
We showcase our grantees and their projects here and continuously update this page as new projects are added.
Physiological and behavioral effects of nicarbazin on feral urban pigeons (Columba livia)
Grantee: Jessica X. Wright-Lichter
Institution: Tufts University
Project summary
The oral contraceptive Nicarbazin (NCZ) has been shown to be effective in urban pigeons. However, despite evidence that it may limit birds’ ability to cope with high heat, the side-effects of prolonged exposure to NCZ on pigeons have not been studied. In this project, feral pigeons will be treated with NCZ and exposed to increased ambient temperature to assess their responses. Changes in corticosterone levels will be used as a physiological proxy for welfare. The researchers will also look for behavioral correlations by measuring the onset and frequency of heat-mediating behaviors. The behavioral effects of NCZ treatment alone will also be assessed by quantifying impacts on affiliative and aggressive behaviors, social status, and access to feed at bait sites.
Grantee: Jessica X. Wright-Lichter
Institution: Tufts University, United States
Grant amount: $30,000
Grant type: Small grants
Focal species: Urban pigeon (Columba livia domestica)
Conservation status: Least concern
Disciplines: Physiology, ornithology, animal welfare science
Research location: United States
Project summary
Nicarbazin (NCZ) is an oral contraceptive that has been shown to be effective in feral urban pigeons (Columba livia). However, although it is EPA-approved and widely marketed, no published studies examine the impact of prolonged exposure to NCZ on the pigeons beyond the contraceptive effect. This is concerning because evidence from agricultural use of the compound (where it was originally developed as an antiparasitic drug) suggests that NCZ exposure may limit the ability of birds to cope with high heat.
To study the impact of NCZ treatment on pigeon welfare, especially as a function of heat exposure, feral pigeons will be treated with NCZ for three weeks before being exposed to increased ambient temperature for four hours to assess their physiological and behavioral responses compared to a control group. This project will use changes in levels of the hormone corticosterone as a physiological proxy for welfare in exposed pigeons. The researchers will also look for behavioral correlations by measuring the onset and frequency of heat-mediating behaviors (e.g., panting, wing-spreading). The behavioral (and plausibly welfare-relevant) effects of NCZ treatment alone will also be assessed by quantifying impacts on affiliative and aggressive behaviors, social status, and access to feed at bait sites.
Why we funded this project
We funded this project because we see wildlife fertility control — particularly applied to urban pigeons — as a highly promising near-term intervention. We are especially interested in indirect welfare effects of fertility control (e.g.,on juvenile welfare and survival), but we have also been concerned by the lack of research on direct welfare impacts. This study will focus on direct welfare impacts while also providing some of the first data on NCZ’s effects on pigeon social dynamics, which are likely to be very important determinants of overall welfare. These data could then be used to guide the application of NCZ contraceptives (e.g., their seasonal timing) to maximize pigeon well-being while successfully controlling urban pigeon populations.
Development of novel measures of welfare in juvenile European starlings exposed to nutritional stress
Grantee: Melissa Bateson
Institution: Newcastle University
Project summary
Nutritional stress causes massive mortality in juvenile European starlings and has lifetime welfare consequences for survivors. The aim of this project is to identify the metabolic “fingerprint” of nutritional stress in starling nestlings and to validate molecular biomarkers that can be used to assess the welfare of wild starlings. This project will use untargeted metabolomics to identify multiple novel biomarkers of exposure to nutritional stress. This “fingerprint” will be validated by testing whether it predicts gold-standard behavioral measures of adult affective experience in a cohort of laboratory-raised birds. The aim will be to identify an applicable panel of metabolites that can be measured from feathers and guano.
Grantee: Melissa Bateson
Institution: Newcastle University, United Kingdom
Grant amount: $60,000
Grant type: Challenge grants
Focal species: Starlings (Sturnidae sp.)
Conservation status: Least concern
Disciplines: Physiology, ornithology
Research location: United Kingdom
Project summary
Juveniles of passerine species such as the European starling (Sturnus vulgaris) experience massive mortality, much of which is caused by direct or indirect effects of nutritional stress. Of birds that survive, many will bear the “scars” of early-life stress that have consequences for their welfare. The aim of this project is to identify the metabolic “fingerprint” of nutritional stress in starling nestlings and to validate sensitive and non-invasive molecular biomarkers that can be used to assess the welfare of wild starlings.
This group has been developing the hypothesis that biomarkers of biological age not only predict future morbidity and mortality, but also reflect the quality of an animal’s cumulative lifetime experience. Existing metrics of biological age, particularly telomere length, require invasive blood samples, and measurements are imprecise, meaning that large sample sizes are currently required to obtain significant effects in epidemiological studies. Estimating biological age based on measuring multiple age-related biomarkers (as is typical in the human aging literature) is likely to be more reliable than using telomere length alone.
This project will use untargeted metabolomics to identify multiple novel biomarkers of exposure to nutritional stress in nestling starlings. This “fingerprint” will be validated by testing whether it predicts gold-standard behavioral measures of adult affective experience in a cohort of laboratory-raised birds. Metabolomics measures thousands of small molecules in one biological sample and can be performed on a range of tissues including blood, hair, and urine. The aim will be to identify an applicable panel of metabolites that can be measured cheaply and easily from feathers and the uric acid component of guano.
Why we funded this project
This project should introduce a novel indicator of long-term welfare that is less invasive, requires fewer resources, and is potentially more reliable than similar existing methods. The PI is a world leader in the field of animal behavior and is the main originator of using biological aging to understand long-term animal welfare, especially in non-model species. For that reason, we are especially confident in this work being high-quality and having great academic reach and influence.
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Integrating individual-level juvenile welfare in dynamic habitats across time and space
Grantee: Tom Luhring
Institution: Wichita State University, Texas State University, and Stephen F. Austin University
Project summary
The project will track four populations of juvenile lesser sirens in Eastern Texas within and across years. Sirens’ health is directly affected by their environment through the impacts of resource availability on body condition and growth rates. Furthermore, sirens show strong size-dependent and seasonal shifts in antagonistic behaviors, which lead to acute injuries. This project will use water-borne corticosterone release rates to investigate changes in stress physiology as a function of changes in the environment experienced by the individual (population density, drought severity index, water temperature, pH, conductivity) across time and space to understand coping capacity. This data will also be used to investigate the welfare impact of an established marking technique compared to a novel machine-learning approach.
Grantee: Tom Luhring
Institutions: Wichita State University, Texas State University, and Stephen F. Austin University, United States
Grant amount: $162,604
Grant type: Challenge grants
Focal species: Sirens (Siren intermedia)
Conservation status: Least concern
Disciplines: Herpetology, physiology, climate science
Research location: United States
Project summary
The project will track individual juvenile lesser sirens (Siren intermedia) within and across years for four populations in Eastern Texas. The lack of a terrestrial life-stage and severely limited overland dispersal ability means that hydrologically isolated pools function as closed populations, facilitating recaptures and simplifying demographic estimates. Siren health is directly impacted by the effects of the environment (e.g., drought conditions) through the impacts of resource availability on body condition and growth rates. Furthermore, sirens show strong size-dependent and seasonal shifts in antagonistic behaviors such as biting which lead to acute injuries.
Aquatic amphibians are especially well-suited for the collection of water-borne stress hormones (corticosterone), which offer the least invasive method of evaluating an integrated measure of corticosterone levels that are passively being released through the skin, gills, feces, and urine. This project will use water-borne corticosterone release rates to investigate changes in stress physiology as a function of changes in the environment experienced by the individual (population density, drought severity index, water temperature, pH, conductivity) across time and space to understand coping capacity. These data will also be used to investigate the welfare impact of an established marking technique compared to a novel approach based on pattern recognition by a machine-learning algorithm.
Why we funded this project
Juvenile mortality is especially high in amphibians, and amphibian welfare in general is a neglected subject. This project should provide proof of concept for a cost-effective approach for assessing welfare at both an individual and population level. The waterborne measurements have the potential to integrate corticosterone over a longer period of time, increasing its reliability as a welfare indicator. Finally, this project will test a novel, non-invasive approach to mark-recapture studies, which could facilitate much better individual-level welfare research for amphibians and other (especially aquatic) animals in the future.
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Evaluating short- and long-term impacts of injury and illness on wild bird welfare
Grantee: Katie LaBarbera
Institution: San Francisco Bay Bird Observatory
Project summary
Surprisingly little is known about how illness and injury impact the welfare and survival of wild animals, as detecting and assessing injuries and tracking animals to determine their fates is challenging. Yet bird banding stations and wildlife rescues require this information to decide whether birds can be ethically released with long-term impairments. This project will use the San Francisco Bay Bird Observatory (SFBBO)’s long-term bird-banding dataset, which spans over 30 years and 100,000 captures, to investigate these questions in wild birds. Bird banding involves close examination of wild individuals who are frequently recaptured over time. With a high rate of recapture, the SFBBO tracks individuals over years, monitoring their injuries and health, and estimating survival.
Grantee: Katie LaBarbera
Institution: San Francisco Bay Bird Observatory, United States
Grant amount: $20,000
Grant type: Challenge grants
Focal species: Wild birds
Conservation status: Least concern
Disciplines: Wildlife rehabilitation, ornithology
Research location: United States
Project summary
There is surprisingly little known about how illness and injury impact the experience of wild animals. Studying such patterns can be limited by the challenges of detecting and assessing injuries and then following up to determine individual fate in wild animals. The San Francisco Bay Bird Observatory’s (SFBBO) long-term bird-banding dataset (>30 years and >100,000 captures) is well-suited to address these questions in wild birds.
Bird banding involves close examination of wild individuals, and individuals are frequently recaptured over time. The SFBBO has a high rate of recapture, which allows them to track individuals over years and to estimate survival, tracking the state of injuries and bird health over multiple years. Understanding how injury impacts individual welfare and survival is of both intellectual and practical value. Bird banding stations vary considerably in their criteria for deciding whether an injured bird should be released or taken to a wildlife rescue. Wildlife rescues must in turn decide whether birds can be ethically released with long-term impairments; for example, many rescues will euthanize rather than release one-legged songbirds. Banding stations and wildlife rescues need real data on wild birds' experiences and prognoses to inform such policies; otherwise, they risk enacting harm.
Why we funded this project
With thousands of wild animal rehabilitation centers in the US alone, this study could provide information that would allow wild animal rehab staff to make data-driven decisions about their bird patients. We think there may be potential to greatly grow interest in the wild animal welfare community via connections with wild animal rehabilitation groups, and this project could provide connections to that community. The project also advances one of our core goals — understanding what wild animals’ lives are like — using an existing and humanely acquired dataset, by providing data on injury rates, severity, and recovery processes. The data could be used to define a metric of “time spent suffering” for injured songbirds.
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Determining the practical and statistical methods necessary for employing field-based metrics of welfare on wild, juvenile, birds
Grantee: Daniel Hanley
Institution: George Mason University
Project summary
Because welfare can vary between individuals and throughout the life of an animal, methods for measuring, assessing, and comparing welfare have been a barrier to our understanding of juvenile welfare. Initial investigations of welfare metrics are needed to estimate age-specific welfare in wild juvenile animals, to determine how they deviate from population-level estimates, and to extend methods and metrics to other systems. This study will examine welfare in free-living prothonotary warblers to establish standardized field and analytical procedures necessary to obtain age-specific animal welfare estimates. Prothonotary warblers are an ideal model system for studying age-specific welfare because they have well-defined life stages, face unique environmental risks, have variable survival, and nest within cavities, affording a degree of standardization and control.
Grantee: Daniel Hanley
Institution: George Mason University, United States
Grant amount: $60,000
Grant type: Challenge grants
Focal species: Prothonotary warbler (Protonotaria citrea)
Conservation status: Least concern
Disciplines: Ornithology, animal behavior, population ecology
Research location: United States
Project summary
The juvenile stage is where welfare conditions are likely the most variable and impactful on an individual’s growth and behavior. Unfortunately, methods for measuring, assessing, and comparing welfare have been a barrier to our understanding of juvenile welfare. Like other aspects of animal life history, welfare will vary between individuals and also over the lives of animals in an age-specific fashion. Thus, metrics such as welfare expectancy can inform us of the welfare that an organism is likely to experience, similar to how life expectancy can provide an estimate on how much longer an organism may live.
This study examines welfare in free-living juvenile songbirds to establish standardized field and analytical procedures necessary to obtain age-specific animal welfare estimates. Prothonotary warblers are an ideal model system for studying age-specific welfare because they have well-defined life stages (i.e., egg, nestling, fledgling, subadult, adult), face unique environmental risks (e.g., drought and flooding), and have variable survival. Furthermore, members of this species nest within cavities, which affords a degree of standardization and control necessary for an initial investigation of welfare metrics. Such initial investigations are crucial to estimate age-specific welfare on wild juvenile animals, to determine how they deviate from population-level welfare estimates, and to extend these methods and metrics to other systems.
Why we funded this project
We funded this project because it sought to explicitly quantify welfare across life stages, using multiple physiological, behavioral, and environmental/demographic indicators. Knowing how (and ideally why) average welfare differs over the course of life in a population could have important implications for interventions to improve their welfare (e.g., fertility control). We were also impressed with this PI because he engages numerous students in their lab and is relatively early in his own career, potentially allowing for pivot to focus more on wild animal welfare. He also demonstrated a good understanding of Wild Animal Initiative’s research on the welfare expectancy framework and sought to put the concepts into practice. That sort of theory-to-practice pipeline would represent a significant step for welfare biology as a research field.
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Thermal imaging to investigate physiological state in altricial nestlings
Grantee: Paul Jerem
Institution: Tufts University
Project summary
Animal stress responses evolved to increase survival, in part by stimulating behaviors that reduce exposure to challenging situations. However, young birds who are entirely reliant on their parents (“altricial”) are incapable of acting to change their circumstances, potentially exposing them to the damaging effects of chronic stress. Such species are known to suppress aspects of their stress physiology during development. However, it remains unclear if other parts of the system remain active and could serve as useful indicators for efforts to improve early life welfare. This project seeks to investigate this possibility in juvenile house sparrows (Passer domesticus) using a novel, non-invasive method for inferring internal state — thermal imaging of body surface temperatures.
Grantee: Paul Jerem
Institution: Tufts University, United States
Grant amount: $37,780
Grant type: Challenge grants
Focal species: House sparrow (Passer domesticus)
Conservation status: Least concern
Disciplines: Physiology, ornithology
Research location: United States
Project summary
Animal stress responses evolved to increase survival, in part by stimulating behaviors that reduce exposure to challenging situations. However, young birds who are entirely reliant on their parents (“altricial”) are incapable of acting to change their circumstances, potentially exposing them to the damaging effects of chronic stress. Such species are known to suppress aspects of their stress physiology during development. However, it remains unclear if other parts of the system remain active and could serve as useful indicators for efforts to improve early life welfare. This project seeks to investigate this possibility in juvenile house sparrows (Passer domesticus) using a novel, non-invasive method for inferring internal state — thermal imaging of body surface temperatures.
Why we funded this project
We especially want to understand juvenile welfare, because in most species that is the most experienced life stage, and often the most vulnerable. However, developmental changes can make it difficult to compare welfare between juveniles and adults. This project will calibrate a non-invasive proxy of welfare that can be applied to both adult and altricial juvenile birds, enabling not only better welfare assessments, but more effective lifetime comparisons. A better understanding of the “shape” of lifetime welfare would in turn inform interventions that might disproportionately affect individuals of certain ages.
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It takes guts to grow in the city: the role of the gut microbiome in the welfare of juvenile urban birds
Grantee: Pablo Capilla-Lasheras
Institution: University of Glasgow
Project summary
Approximately 30 million blue tits hatch every year in UK cities, but around 63% die as juveniles. One reason for this may be that juvenile birds in urban habitats tend to have low-quality diets, causing stunted growth and increased early-life mortality. Research suggests that gut microbiome composition may contain indicators of an animal’s welfare, but this has received little attention in a wild animal context. This project will combine telomere attrition, begging behavior, and other health metrics with a study of juvenile birds’ gut microbiomes to investigate how to improve the welfare of juvenile blue tits in urban areas. It will also test the potential for gut microbiome enrichment to improve the life experience of juvenile birds in urban habitats.
Grantee: Pablo Capilla-Lasheras
Institution: University of Glasgow, United Kingdom
Grant amount: $59,052
Grant type: Challenge grants
Focal species: Blue tits (Cyanistes caeruleus)
Conservation status: Least concern
Disciplines: Physiology, population ecology, animal welfare science, ornithology, animal behavior
Research location: United Kingdom
Publications
Reid, R., et al. (2024). The impact of urbanization on health depends on the health metric, life stage and level of urbanization: a global meta-analysis on avian species. Proceedings of the Royal Society B, 291(2027). https://doi.org/10.1098/rspb.2024.0617
Project summary
Amongst the novel stressors that wildlife face in cities, shifts in diet are prevalent and have negative consequences for welfare, particularly in juveniles. Research clearly shows that juvenile birds in urban habitats have low-quality diets, causing stunted growth and increased early-life mortality. For example, in the UK alone, approximately 30 million blue tits hatch every year in cities, but around 63% of them die as juveniles. This project will study juvenile blue tits and investigate how to improve their welfare in urban areas using an integrative approach that will combine metrics of animal welfare with the study of gut microbiomes. Human and captive animal studies suggest that the gut microbiome composition may contain indicators of an animal’s welfare, but this has received little attention in a wild animal context. This study will combine a physiological welfare indicator (telomere attrition), a behavioral welfare indicator (begging behavior), and other health metrics with a study of juvenile birds’ gut microbiomes to link poor-quality urban diets, gut microbiome composition, and welfare. The project will also test a potential near-term dietary intervention (gut microbiome enrichment) to improve the life experience of juvenile birds growing in urban habitats.
Why we funded this project
Welfare is shaped by, and in turn influences, numerous aspects of an animal’s phenotype. Individual welfare indicators offer only limited insights, but combining indicators across multiple domains is thought to be extremely important for triangulating affective state, or “true” welfare. Because the gut microbiome represents a partially distinct domain, understanding how it relates to welfare could therefore strengthen all of our other indicators when they are used in combination. We were especially interested in this project due to the inclusion of an intervention experiment that could be implemented in the near future. Finally, this project will support an early-career researcher with an interest in wild animal welfare.
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The impact of road noise on the welfare of free-living juvenile white-footed mice
Grantee: Michael Sheriff
Institution: University of Massachusetts Dartmouth
Project summary
This project will examine how road noise impacts the ability of juvenile white-footed mice in Massachusetts to respond to the threat of predation. Preliminary work has shown that experimental manipulation of road noise disrupts the foraging responses of (adult) small mammals to predation risk, possibly by masking their ability to perceive predators’ auditory cues. Perception of predation threat will be experimentally manipulated by auditory playback of owl noises at sites near and far from the highway, paired with controls at the same distances from the highway without auditory playback. Anxiety-related behaviors will be recorded in juveniles in an open field trap, and their feces will be studied to assess physiological stress and nutritional status.
Grantee: Michael Sheriff
Institution: University of Massachusetts Dartmouth, United States
Grant amount: $60,000
Grant type: Challenge grants
Focal species: White-footed mice (Peromyscus leucopus)
Conservation status: Least concern
Disciplines: Human-wildlife conflict, animal behavior, population ecology, mammalogy
Research location: United States
Project summary
This project will examine the impact of road noise on juvenile welfare in white-footed mice in Massachusetts. The project will focus on how road noise impacts the ability of juveniles to respond appropriately to the threat of predation (the most common cause of juvenile small mammal mortality). Preliminary work has shown that experimental manipulation of road noise (played at 62-65dB, which is equivalent to 100m into the forest from a major thoroughfare to Boston, MA) disrupts the normal foraging responses of (adult) small mammals to predation risk, possibly by masking their ability to perceive auditory cues of predators. Perception of predation threat will be experimentally manipulated by auditory playback of owl noises at sites near and far from the highway, paired with controls at the same distances from the highway but without auditory playback. Anxiety-related behaviors will be recorded in juveniles in an open field trap (which they voluntarily enter for feed), and their feces will be studied to assess physiological stress and nutritional status.
Why we funded this project
Road noise has dramatically increased and is potentially a major anthropogenic threat to wild animal welfare, and one which might be easily ameliorated through policy changes (e.g., improved sound barriers). This project is especially interesting because it focuses on a less obvious effect of road noise, potentially increasing the risk of predation by masking predator cues. This becomes even more interesting in the context of growing literature on the “ecology of fear,” sublethal effects of predators on prey behavior. If road noise makes prey unaware of risks, it could actually reduce their chronic stress despite exposing them to greater risk of death. We are excited for this project to explore those issues, although we are prepared for a complex result. Additionally, we wanted to support this PI because of their strong record of engaging students in their research and influencing their career trajectories.
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To feed or not to feed wild birds
Grantee: Marion Chatelain
Institution: University of Innsbruck
Project summary
Despite providing otherwise limited resources, bird feeders may attract predators, facilitate the exchange of pathogens, and increase intraspecific conflict. This project will study two common bird species: great tits, who use feeders intensively, and black redstarts, who typically do not use feeders. By monitoring the use of nestboxes in gardens with or without feeders, the project aims to evaluate social stress and competition for nesting sites caused by bird feeding. Fecal samples from nestlings will also be analyzed to understand impacts on stress physiology, growth rate, and ectoparasite load.
Grantee: Marion Chatelain
Institution: University of Innsbruck, Austria
Grant amount: $29,943
Grant type: Seed grants
Focal species: Great tits (Parus major), black redstarts (Phoenicurus ochruros)
Conservation status: Least concern
Disciplines: Ecological modeling, community ecology
Research location: Austria
Project summary
Bird feeding can provide birds with sustenance through challenging times, such as winter, and in places where they would not be able to find abundant natural foods, such as inner cities. However, bird feeding may also have negative consequences by aggregating birds in one location, attracting predators, facilitating the exchange of pathogens, and increasing intraspecific conflict.
This project will consider two common bird species: great tits, who use feeders intensively, and black redstarts, who typically do not use feeders. By monitoring the use of nestboxes separately targeting these two species, across private gardens that do or do not provide feeders, the project aims to evaluate social stress and competition for nesting sites caused by bird feeding. Fecal samples from nestlings will also be analyzed to understand impacts on stress physiology, growth rate, and ectoparasite load.
Why we funded this project
With the popularity of bird feeding and the density of private gardens in cities, understanding the pros and cons of bird feeding may be crucial for understanding and ultimately improving the welfare of urban birds. We especially appreciate that this project will consider both target and non-target bird species, and focuses on the welfare of juveniles.
Density-Dependent Welfare in Wild Bird Social Networks: Linking resource distributions with disease dynamics
Grantee: Joshua Firth
Institution: University of Oxford
Project summary
This project will investigate how various potential density-dependent drivers of welfare interact and influence net welfare in two species of tit. Population density is expected to be directly related to infectious disease transfer and increased competition, but also to covary with processes that are potentially beneficial to welfare. The study will use historical data to determine how the relationship between population density and individual welfare is shaped by infectious disease, body condition, and mortality risk. The investigators will then manipulate density experimentally to test model outputs and determine potential causal links.
Grantee: Josh Firth
Institution: University of Oxford, United Kingdom
Grant amount: $99,466
Grant type: Challenge grants
Focal species: Great tits (Parus major), blue tits (Cyanistes caeruleus)
Conservation status: Least concern
Disciplines: Animal behavior, community ecology, infectious disease, population ecology, ornithology, bio/eco-informatics, ecological modeling, animal welfare science
Research location: United Kingdom
Project summary
This project seeks to understand the interplay among various potential density-dependent drivers of positive and negative welfare impacts to determine net welfare related to aggregation (increased density) in wild birds (two species of tit). Infectious disease transfer and increased competition, both likely to reduce welfare, are expected to be directly related to population density. However, population density also covaries with processes that are potentially beneficial to welfare, such as congregation around areas that provide high nutrition, various social benefits, opportunities for increased cooperation, or access to social information. The study will use long-term datasets to empirically determine how the relationship between population density and individual welfare is shaped by infectious disease, including the density-dependent relationship with disease spread. Additionally, using historical data, the project will test how population density, mediated by social contact, environment, and disease, determines individuals’ body condition and mortality risk. Based on the results of this observational phase of the study, the investigators will then manipulate density experimentally, to test model outputs and determine potential causal links.
Why we funded this project
This project brings two unique advantages. First, the investigators have access to a population that has been subject to intensive monitoring for decades, meaning that much of the relevant ecological context is known and there is historical data to analyze retrospectively. Secondly, in part due to this long-term monitoring, the birds are tagged and observed at feeding stations equipped with RFID tags/readers that allow for experimental manipulation of the density and identity of birds feeding at particular stations. By empirically testing density-dependent models of welfare, the project could provide an increased understanding of the interplay among population density, infectious disease, and various social and environmental characteristics, and in doing so, identify drivers of welfare in wild birds.
