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.
Field tests of bee welfare
Grantee: Vivek Nityanada
Institution: Newcastle University
Project summary
The goal of this project is to develop a cognitive judgment bias test for wild bees and pilot its use in the field. The project will investigate how bee cognitive biases and reward responses vary with factors expected to cause high or low welfare, such as light and vehicular pollution. The researchers will also develop a “lick-o-meter” for assessing welfare based on individual variation in the bees’ consumption of a sugar-water reward, with the expectation that bees in low-welfare environments will display less enthusiasm for consuming the sugar-water.
Grantee: Vivek Nityananda
Institutions: Newcastle University, United Kingdom
Grant amount: $194,317
Grant type: Challenge grant
Focal species: Buff tailed bumblebees (Bombus terrestris)
Conservation status: Least concern
Disciplines: Animal welfare science, entomology, animal behavior
Research location: United Kingdom
Project summary
Studying affective states in animals has been a key component towards assessing their welfare. Most studies that have used this approach have focused on vertebrates. Yet, the rapid decline in insect numbers calls out for novel methods to monitor their welfare and measuring their affective states would be an important approach. A few recent papers have indicated the presence of affective states in insects, especially bees. These papers have used judgement bias tests in laboratory settings. Recent findings using an active choice test in our lab have also shown robust evidence of affective states in bees due to changed expectations of rewards. However, there is no research looking at these states in the wild. To address this gap, this project seeks to develop and validate new tests for bee affective states in the wild and use these to assess the welfare of bees in the field.
This project will assess whether environments predicted to induce poor welfare and negative valence for bees– such as ones with poor nutrition or light pollution- induce changes in predicted markers of poor welfare. We will use performances in judgement bias tests and reduced responses to rewards in the wild as behavioral markers of welfare. We will also measure the role of neuromodulators (dopamine, serotonin) by measuring the differences in their expression, and of genes involved in their synthesis pathways, in the brains of wild bees in different environments. Measuring changes in these three different markers across different low-welfare environments will help validate them as measure of bee welfare and develop novel markers for wild bee welfare. They will thus providing vital tools for further biological and environmental research in a variety of pollinators.
Why we funded this project
We are generally excited to support this project because it focuses on a wild insect. Insects are extremely abundant and their welfare is typically neglected. Validating a cognitive judgment bias test that can be implemented in the field for a wild insect would be a powerful step forward.
Parasites in the city: How is the impact of parasites on wild animal welfare affected by urbanization?
Grantee: Amanda Trask
Institutions: Institute of Zoology (IOZ), Zoological Society of London (ZSL)
Project summary
This project will evaluate the extent to which parasitism and urbanization impact wild animal welfare, both independently and synergistically, using physiological data on the internal and external parasite loads of deceased gray squirrels, as well as their body condition, immune function, and stress response. The researchers will also collect behavioral welfare indicators from other squirrels using camera traps. This data will be collected along a gradient of urbanization levels and analyzed in the context of the squirrels’ sex and age, to compare population-level welfare across sites varying in degree of urbanization and average parasite metrics and predict how future increases in urbanization might impact wildlife welfare.
Grantee: Amanda Trask
Institutions: Institute of Zoology (IOZ), Zoological Society of London (ZSL), United Kingdom
Grant amount: $199,941
Grant type: Challenge grant
Focal species: Eastern grey squirrel (Sciurus carolinensis)
Conservation status: Least concern
Disciplines: Infectious disease, population ecology
Research location: United Kingdom
Project summary
Parasitism is likely a key determiner of wild animal welfare, while rapidly increasing urbanisation presents novel challenges and welfare threats, yet the extent that parasitism and urbanisation impact wild animal welfare, both independently and synergistically, remains a major knowledge gap. An individual’s parasite infection status, and the associated welfare impacts, is dependent on parasite exposure risk and susceptibility. Urbanisation may alter exposure risk, for example through changes to population density and resource distribution, and susceptibility, for example through altered host immune function from exposure to urban stressors. Urbanisation may also compound impacts of parasitism, if chronically stressed individuals are less able to cope with further welfare challenges, resulting in synergistic negative welfare effects. Furthermore, welfare impacts of parasites and urbanisation may vary across sex- and life-stage classes, for example due to hormonal influences and changes in immune function with chronic exposure to urban pollution.
We will address this knowledge gap, using grey squirrels from UK sites across an urbanisation gradient. We will use detailed individual-level data on parasite loads and physical and physiological welfare indicators, collected from dead squirrels killed as part of non-native species management, to determine welfare impacts across sites varying in degree of urbanisation, and across sexes and life stages. Then, we will use behavioural indicators from camera trap data to determine associations between population-level welfare, parasite prevalence and degree of urbanisation. Finally, we will estimate ‘welfare expectancy’ of individuals from different populations using sex- and life-stage specific welfare scores. We will expand on current theory and develop a modelling tool to incorporate demographic and environmental stochasticity in welfare states into population models, to aid prediction of how increasing urbanisation may impact wildlife welfare in the future. This study will provide vital knowledge to aid understanding and prediction of the experience and future responses of wild animals to parasites in the context of increasing urbanization, facilitating design and integration of welfare-friendly urban environments for wildlife.
Why we funded this project
Gray squirrels are abundant, they live in close proximity to humans, and they could benefit from welfare interventions such as wildlife fertility control in the near future. Gray squirrels are not native in the UK, where this study will be conducted, and the welfare of non-native species is generally understudied or undervalued compared with native species of conservation interest. This project provides a special opportunity to take advantage of data from squirrels who are being killed as part of a government program, and to access valuable metrics that are hard to measure non-invasively, thereby creating from their deaths an opportunity to gain valuable insights that could ultimately help other squirrels. In addition to their good range of welfare indicators, we appreciate that this project will consider sex- and age-specific variation in welfare impacts and attempt to estimate “welfare expectancy” at a population level.
Are we making urban wildlife sick?
Grantee: Carl Soulsbury
Institution: University of Lincoln
Project summary
The goal of this project is to test whether differences in welfare among individual red foxes and individual European hedgehogs are explained by specific environmental stressors arising from urbanization (e.g., increased human population density, noise pollution, or reduced habitat heterogeneity). Notably, on a population level, foxes appear to have fared well alongside humans, while hedgehogs have struggled to cope with urbanization. The study will confirm whether this contrast is also seen at the level of individual welfare, and offers a unique opportunity to identify common environmental stressors that may be impacting the health and welfare of urban wildlife more generally. To assess welfare, the project will perform cognitive judgment bias and novel object tests and combine them with non-invasive indicators of physiological stress (fecal glucocorticoids and eye/ear temperature) and health (pathogen load).
Grantee: Carl Soulsbury
Institutions: University of Lincoln, United Kingdom
Grant amount: $148,741.43
Grant type: Challenge grant
Focal species: Red fox (Vulpes vulpes) and European hedgehog (Erinaceus europaeus)
Conservation status: Least concern
Disciplines: Animal welfare science, animal behavior, physiology
Research location: United Kingdom
Project summary
Urbanisation causes profound changes to biodiversity. For many species living in urban areas, there is evidence that urban living leads to greater disease prevalence. It is unclear, however, (a) what factors drive this higher disease prevalence and (b) whether this leads to poorer wild animal welfare. We propose a study to compare two urban-dwelling species, red foxes and Eurasian hedgehogs, where we will characterize pathogen prevalence, load, and diversity across an urban-rural gradient. This study will be carried out at two scales: firstly, we will link pathogen loads, faecal glucocortoicoids and habitat at the landscape level, allowing us to broadly understand if urbanisation is associated with increased pathogen loads. We will then carry out a second, more detailed data collection where we will combine pathogen data with measures of stress (infra-red thermography, faecal glucocorticoids) and behavioural measures of affective valence (novel object and judgement bias tests). Here, we will link together pathogen loads and different measures of welfare at the individual level. Ultimately, our aim is to test, within each species, whether population differences in health and welfare are explained by environmental stressors arising from urbanisation (e.g., increased human population density and reduced habitat heterogeneity).
Why we funded this project
We appreciate that this project considers specific characteristics of urban environments, as opposed to simply comparing urban environments with rural ones. This way, it has more potential to inform near-term interventions. Plus, the project design humanely allows for animals’ voluntary participation. In addition to using an effective suite of welfare indicators to investigate the impact of different parasite loads on welfare, the combination of cognitive bias testing with non-invasive physiological stress metrics will provide information on the validity of those metrics, which are being used concurrently in other projects.
Does diet mediate effects of sublethal parasitic infections on host welfare?
Grantee: Amanda Koltz
Institution: University of Texas at Austin
Project summary
This project will test how infection by parasitic worms (helminths) influences host welfare in white-footed deer mice by evaluating the relationship between parasite burden and host body condition, microbiome, and stress physiology, as well as behaviors associated with anxiety (negative welfare) and exploration (positive welfare). The researchers will experimentally manipulate parasite burden by intervening to apply anti-parasitic medication (Ivermectin) as a treatment for some mice who were already infected with helminths.
Grantee: Amanda Koltz
Institutions: University of Texas at Austin, United States
Grant amount: $167,237
Grant type: Challenge grant
Focal species: White-footed mouse (Peromyscus leucopus) and their helminth parasites
Conservation status: Least concern
Disciplines: Infectious disease, animal welfare science, animal behavior, physiology, community ecology
Research location: United States
Project summary
Parasite-mediated changes in host traits can have far-reaching ecological effects. Even sublethal infections affect hosts by increasing energetic costs and altering behavior, immunity, and physiology. Yet while many studies have investigated parasite effects on specific host traits, our understanding of how parasites influence overall individual welfare is limited, especially for wild animals. For example, parasites can drive changes in host diet and habitat use that reduce parasite exposure but not necessarily improve other metrics of host welfare. A holistic approach that captures different types of individual-level responses to parasitism is needed to advance our overall understanding of sublethal infections on host welfare. We propose to investigate how parasite burden is associated with individual-level host welfare using white-footed deer mice (Peromyscus leucopus) and their helminth parasites as a model system. Specifically, by experimentally removing gastrointestinal helminth parasites from P. leucopus, we will test how variation in parasite burden influences individual host body condition, diet and nutrition, microbiome, stress physiology, anxiety-like behavior, and exploratory behavior in forested ecosystems. P. leucopus has become the dominant small mammal species over the last 40 years in the northern Great Lakes region. It experiences sublethal infection by a range of helminth parasites and is a reservoir for several zoonotic pathogens, making its host-parasite dynamics highly relevant to the health of humans and other wildlife. By examining how infection levels relate to the diet, body functions, and behavior of P. leucopus, this study will advance our understanding of how non-lethal parasitic infections affect the welfare of an extremely widespread wild animal species.
Why we funded this project
We are excited to fund a study on wild mice, a highly numerous and neglected group, and especially one with such a welfare-friendly experimental approach — curing parasitic infections rather than causing them. The project also uses a holistic suite of physiological and behavioral indicators that should allow the researchers to disentangle overall welfare from narrow, mechanistic impacts of infection on the health and nutrition domains.
Developing an automated cognitive bias task for wild squirrels
Grantees: Vikki Neville, Lisa Leaver
Institutions: University of Bristol, University of Exeter
Project summary
The goal of this project is to develop a cognitive judgment bias test for use in wild gray squirrels that capitalizes on their innate behavior, avoiding the need for the extensive type of training that is usually part of cognitive judgment bias tests in captive settings. By making use of the widely available Raspberry Pi platform, the test should be relatively easy for other researchers to replicate and adapt for use in other species. To validate the test itself, the research team will also assess how measurement of cognitive judgment bias varies with factors assumed to affect the valence of animals participating in the test, such as distance from cover and levels of food provisioning in the environment, as well as how the test results correlate with other potential non-invasive behavioral and physiological indicators of welfare, such as the distance at which a squirrel flees from approaching humans, hair cortisol concentration, and real-time fluctuations in eye temperature in response to stimuli during the the test.
Grantees: Vikki Neville and Lisa Leaver
Institutions: University of Bristol, University of Exeter, United Kingdom
Grant amount: $157,049
Grant type: Challenge grant
Focal species: Grey squirrel (Sciurus carolinensis)
Conservation status: Least concern
Disciplines: Animal welfare science, physiology, animal behavior
Research location: United Kingdom
Project summary
The development of the cognitive judgment bias (CJB) task for non-human animals revolutionised the field of animal welfare. The CJB task: (a) is thought to measure both relatively better and relatively poorer welfare across the full spectrum of possible welfare states, (b) is non-invasive, and (c) has been validated using a meta-analytic approach. Moreover, the theoretical basis of the predictions for the CJB task should be applicable across taxa and, accordingly, it has been used successfully in many species. However, to date, its use has largely been in captive species and there are a dearth of examples in wild animals. A key barrier to implementation is that it is difficult to train animals to associate stimuli with particular outcomes: the time needed to do so makes these studies unsuccessful or infeasible in non-captive populations of animals. We propose that this could be overcome by capitalising on the natural behaviour of a species to reduce training time and by using equipment that allows automation of stimulus presentation and data collection.
The main aim of our proposed project is to develop a CJB task for use in wild animals, in particular wild squirrels. Our key objectives are to develop a task for collecting CJB data from grey squirrels which: (1) capitalises on their innate behaviour, obviating the need for extensive training, and (2) makes use of Raspberry Pi equipment so that the task can be easily implemented by other researchers and straightforwardly adapted for use across species to measure welfare and validate novel potential measures of welfare.
To assess that our task works as anticipated, secondary objectives will be to: (1) assess how CJB varies with task manipulations designed to alter affective valence (the distance of the equipment from cover, and levels of food provisioning in the environment), and (2) assess how CJB correlates with other potential non-invasive indicators of welfare (e.g. flight distance in response to humans, QBA scores, retrapability, social status, hair cortisol concentration, and fluctuations in eye temperature following positive and negative stimuli on the judgement bias test measured using infrared thermal cameras).
Why we funded this project
As noted above, cognitive bias tests are generally considered to be exceptionally robust welfare indicators, while gray squirrels are an abundant species and a prime target for near-term interventions. Therefore, we are excited to support the development of a cognitive judgment bias test for use on free-living gray squirrels, which will also help to assess the validity of simpler indicators, such as eye temperature and flight initiation distance.
Validating the use of cognitive bias to assess affective valence in wild bird populations.
Grantee: Oliver Burman
Institution: University of Lincoln
Project summary
The goal of this project is to develop and validate a cognitive bias test for assessing the welfare of woodland birds that does not require any training stage, and instead takes advantage of innate attraction and aversion to stimuli that resemble preferred or noxious prey (with a range of likeness accuracy, based on the principle of imperfect Batesian mimicry). Continuing the theme of exploiting natural variation, the project will use spatial variation in numerous components of habitat preferability that can be assumed to directionally affect welfare — such as food abundance and shelter — as natural experiments to validate their cognitive bias tests.
Grantees: Oliver Burman
Institutions: University of Lincoln, United Kingdom
Grant amount: $193,684.17
Grant type: Challenge grant
Focal species: Free-living wild birds, including (but not limited to): blue tits (Cyanistes caeruleus), great tits (Parus major), wrens (Troglodytes troglodytes), coal tits (Poecile ater), European robins (Erithacus rubecula), chaffinches (Fringilla coelebs), greenfinches (Chloris chloris), starlings (Sturnus vulgaris), blackbirds (Turdus merula) and Eurasian jays (Garrulus glandarius).
Conservation status: Least concern
Disciplines: Animal welfare science, ornithology, animal behavior
Research location: United Kingdom
Project summary
Cognitive bias is a robust and validated measure of affective valence effective in a wide variety of animal species. However, this valuable approach has been primarily focused on the welfare assessment of captive animals and has not yet been demonstrated in wild free-living animal populations. This goal is crucial for addressing urgent contemporary issues such as the impact of anthropogenic and climatic change on wild animal welfare and to tackle key conservation challenges. In the first attempt to apply a cognitive judgement bias task in a free-living wild animal population, we found that wild birds struggled to complete the necessary training (discrimination) stage of the cognitive bias task. In the proposed project, our aim is therefore to validate two novel cognitive approaches to assessing affective valence in wild animals that do not require training, in conjunction with established behavioural and physiological indicators of welfare. Firstly, we will investigate a modified cognitive judgement bias task based on the innate avoidance of naturally occurring aversive prey, using the principle of imperfect Batesian mimicry. Secondly, we will modify and validate a cognitive attention bias task that relies on a spontaneous response to a potential threat. Both tasks will be assessed in populations of wild birds using natural variation in affective valence. Our anticipated outcomes are the development of an effective, validated measure of affective valence applicable to wild birds without the need for capture/restraint that can be translated across species; an invaluable tool in the assessment of wild animal welfare in response to a wide variety of environmental challenges.
Why we funded this project
This project’s results are intended to be generalizable to numerous woodland bird species (e.g., tits, wrens, starlings). We also appreciate its creatively humane approach to validation, using innate preferences and natural variation in affective valence, rather than training and experimental manipulation. Plus, the project considers both presumably positive (e.g., food, shelter) and presumably negative (e.g., predator abundance) welfare factors, which further strengthens the validation.
Measuring health and frailty in wild insects
Grantee: Jelle Boonekamp
Institutions: University of Glasgow
Project summary
The aim of this project is to develop a non-invasive frailty index that measures the health of individual insects in their natural habitat and can be applied across species. Using traits applicable to many different insect species, it will develop an insect frailty index, validating it against mortality and fitness data in an insect population by testing whether frail individuals have increased mortality risk and reduced fitness. The project will use data from a long-term field study of a natural population of crickets, which recorded adult crickets from their emergence to death using a network of 140 video cameras. Fitness was measured by genotyping and counting the number of surviving genetic descendants in the following year.
Grantee: Jelle Boonekamp
Institutions: University of Glasgow, United Kingdom
Grant amount: $63,536
Grant type: Ad hoc
Focal species: Field cricket (Gryllinae)
Conservation status: Least concern
Disciplines: Physiology, entomology
Research location: United Kingdom
Project summary
From an evolutionary perspective, health and well-being is best expressed in terms of fitness variation, the logic being that animals who are optimally adapted to their local environment should be healthy. Hence, health and fitness are intimately entwined on a conceptual level. Morphological, behavioral, and physiological traits that are predictive of fitness could provide potential biomarkers of health, and such approaches have been developed for many different wild vertebrate species. However, due to their small size and mobility, it has proven exceedingly challenging to follow individual insects longitudinally in the wild, let alone their descendants, to measure individual performance and fitness. Consequently, there is a paucity of literature on wild insect health and well-being.
The aim of this project is to address this knowledge gap by developing a non-invasive frailty index that measures the health of individual insects in their natural habitat and that can be applied across species. Analogizing to frailty indices used in human patients, this project will develop an insect frailty index using relevant traits applicable to many different insect species. In humans, the frailty index is highly predictive of morbidity and remaining life expectancy. Similarly, this project seeks to validate the insect frailty index against mortality and fitness data in an insect population by testing whether “frail” individuals have increased mortality risk and reduced fitness.
This project is made possible by the work that we have done to establish a long-term field study of a natural population of crickets (WildCrickets.org). Using a network of 140 video cameras, all the adults in the population are longitudinally monitored from their emergence in early spring to their natural death in late summer. All their movements, reproductive behaviors, fights, and predation events are recorded, and fitness is measured by genotyping and counting the number of surviving genetic descendants in the next year.
Why we funded this project
Willingness to investigate the welfare of insects is somewhat rare, as are creative ways to assess their welfare. This project both proposed a potentially usable metric, and has access to an unusually useful resource through the WildCrickets.org project. While any particular approach to assessing welfare in insects is unlikely to work, we are hoping to seed enough approaches and strategies that others take up the call, eventually drawing in enough different approaches to produce usable strategies for assessing insect welfare in the wild. Finally, because many of the project resources were already acquired through other sources, we were to fund exclusively the welfare-focused aspects of the project.
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Integrating behavioral competency and post-release support for reintroduced wildlife: a shift in paradigm for rehabilitation and beyond
Grantee: Karli Rice Chudeau
Institutions: The Marine Mammal Center, University of California, Davis
Project summary
This project investigates post-release support and monitoring to improve outcomes for rehabilitated juvenile pinnipeds. Post-release support will include familiar cognitive enrichment to help released animals adjust gradually and buffer their affective state. Post-release monitoring will consider metrics such as behavioral diversity, energy expenditure, and body condition, and the animals’ specific behavioral profiles will be compared with those recorded from healthy, wild individuals. These metrics will be used to evaluate the effectiveness of post-release enrichment as an intervention for improving welfare outcomes. Cognitive bias tests for affective state carried out during rehabilitation and prior to release will also be considered as potential predictors of post-release welfare.
Grantee: Karli Rice Chudeau
Institutions: The Marine Mammal Center, University of California, Davis, United States
Grant amount: $30,000
Grant type: Seed grants
Focal species: Northern elephant seal (Mirounga angustirostris), eastern Pacific harbor seal (Phoca vitulina richardii)
Conservation status: Least concern
Disciplines: Wildlife rehabilitation, animal behavior, animal welfare science
Research location: United States
Project summary
In many cases, the process of releasing a rehabilitated or translocated animal can be traumatic and removes the animal’s agency, potentially weakening their ability to thrive in the wild. This project investigates post-release support and monitoring to improve outcomes for rehabilitated juvenile pinnipeds. Post-release support will include familiar cognitive enrichment to help released animals adjust gradually and buffer their affective state. Post-release monitoring will consider metrics such as behavioral diversity, energy expenditure (distance traveled), and body condition, and the animals’ specific behavioral profiles (e.g. foraging behavior) will be compared with those recorded from healthy, wild individuals. These metrics will be used to evaluate the effectiveness of post-release enrichment as an intervention for improving welfare outcomes. Cognitive bias tests for affective state carried out during rehabilitation and prior to release will also be considered as potential predictors of post-release welfare.
Why we funded this project
We envision a world in which people take responsibility for improving wild animals’ lives and have the knowledge they need to do so effectively. Rehabilitation is a part of that. However, there has been relatively little research on post-release outcomes for rehabilitated animals. Understanding those outcomes and identifying strategies to improve them could have significant welfare implications, especially for the treatment of juvenile animals, whose life trajectories may be powerfully affected by the rehabilitation and release process. We appreciate that this project combines post-release monitoring with both a specific intervention and pre-release tests of affective state that would not be possible in a wild context.
Integrating nonlethal field and lab assessments of wild fish welfare in the Colorado River in Grand Canyon
Grantee: Isaac Schuman
Institutions: Oregon State University
Project summary
This project will monitor the welfare of three species of fish in the Grand Canyon using a battery of metrics including body condition, gut microbiome, parasite load, and cortisol in skin mucus. The researchers will attempt to validate these as welfare indicators by testing whether they correlate with one another within individual fish, and whether they follow consistent patterns across the three focal species. Finally, they will use long-term population monitoring data to investigate potential correlations between these individual-based welfare indicators and environmental and demographic characteristics of individual study sites, such as food availability and age structure.
Grantee: Isaac Schuman
Institutions: Oregon State University, United States
Grant amount: $30,000
Grant type: Seed grants
Focal species: Flannelmouth sucker (Catostomus latipinnis), humpback chub (Gila cypha), rainbow trout (Oncorhynchus mykiss)
Conservation status: Least concern
Disciplines: Physiology, ichthyology, infectious disease
Research location: United States
Project summary
This project will monitor the welfare of three species of fish in the Grand Canyon using a battery of metrics including body condition, gut microbiome, parasite load, and cortisol in skin mucus. The researchers will attempt to validate these as welfare indicators by testing whether they correlate with one another within individual fish, and whether they follow consistent patterns across the three focal species. Finally, they will use long-term population monitoring data to investigate potential correlations between these individual-based welfare indicators and environmental and demographic characteristics of individual study sites, such as food availability and age structure.
Why we funded this project
We appreciate the variety of potential welfare indicators that this study will measure, and that there will be an explicit attempt to test the validity of the indicators for these particular species. It is exciting to see such a comprehensive analysis of wild fish welfare. We are also interested in the project’s comparison of individual welfare indicators to population-level demographic parameters, as better understanding those relationships could help with both identifying welfare threats from more readily available population data, and with predicting indirect impacts of welfare interventions.
Are populations that are well-adapted to their environment less stressed than those that are not?
Grantee: Ryan S. Mohammed
Institutions: Auburn University
Project summary
In this pilot study, wild-caught guppies will be exposed to an apparent threat of predation as researchers transfer water from a tank containing a common predator (pike cichlid) into their tank. The amount of water transferred from the predators’ tank will be varied to simulate a range of predator densities. Cortisol levels will then be measured in the guppies’ tissue and tank water. These tissue and water cortisol measurements will be compared to develop a protocol for inferring the cortisol levels of fish based on non-invasive water measurements. The researchers hypothesize that the strength of the guppies’ physiological stress response (cortisol) will vary with apparent predation risk.
Grantee: Ryan S. Mohammed
Institutions: Auburn University, United States
Grant amount: $30,374
Grant type: Seed grants
Focal species: Guppy (Poecilia reticulata), jumping guabine (Anablepsoides hartii)
Conservation status: Least concern
Disciplines: Physiology, ichthyology
Research location: Trinidad and Tobago, United States
Project summary
In this project, wild-caught guppies (Poecilia reticulata) will be exposed to an apparent threat of predation by transferring water from a tank containing a common predator (pike cichlid) into their tank. The amount of water transferred from the predators’ tank will be varied to simulate a range of predator densities. Then, cortisol levels will be measured in both the tissue of guppies and the water they are kept in. These tissue and water cortisol measurements will be compared to develop a protocol for inferring the cortisol levels of fish based on non-invasive water measurements. The researchers hypothesize that the strength of the guppies’ physiological stress response (cortisol) will vary with apparent predation risk, and they intend to eventually build on this pilot study by using the developed non-invasive protocol to compare guppies from populations the are adapted to varying intensities of predation.
Why we funded this project
This project will develop a protocol for inferring the cortisol levels of fish based on non-invasive water measurements, which should allow researchers seeking to use cortisol as a metric of physiological stress to avoid needing to kill fish in order to measure the chemical in their tissues. In terms of broader wild animal welfare theory, we also appreciate the project’s focus on the indirect effects of predator-induced fear, which are likely ubiquitous. This project is also intended as a pilot for a larger project that would investigate the impact of evolutionary adaptation to avoid predation on the stress response to the presence of predators.