Developing a consensus profile of wild animal welfare: integrating non-invasive monitoring of the gut microbiome with stress physiology and behavior

Grantee: Sam Sonnega

Institution: University of Massachusetts Dartmouth, United States

Grant amount: $29,130

Grant type: Small grants

Focal species: White-footed mice (Peromyscus leucopus)

Conservation status: Least concern

Disciplines: Physiology, animal welfare science, animal behavior

Research location: United States

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Publications

Sonnega, S. and Sheriff, M.J. (2024). Harnessing the gut microbiome: a potential biomarker for wild animal welfare. Frontiers in Veterinary Science, 11. https://doi.org/10.3389/fvets.2024.1474028

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Project summary

This project will characterize the gut microbiome of wild white-footed mice (Peromyscus leucopus) and investigate its relationship with their stress physiology and behavior, including how it changes in response to ecological pressures. While a growing literature from lab-based studies has demonstrated the link between the gut microbiome and regulation of host physiology and behavior, the generality of these findings in ecological contexts remains largely untested. As part of this project, mice will be trapped during different seasons and fecal samples will be collected from which to measure both glucocorticoid concentrations and gut microbiome composition. Concurrently, open-field trials will be conducted to assess individual variation in cognitive bias towards optimism or pessimism (a well-established behavioral indicator of affective state). The mice’s perception of predation risk will also be experimentally manipulated by exposing free-living mice to playbacks of predator noises. By correlating the gut microbiome with both behavioral and endocrine metrics, a consensus profile of the mice’s welfare will be developed that reflects the complexity of their responses to both predictable and unpredictable environmental perturbations, and how those responses can scale up to population and ecosystem level changes via the demographic effects of stress in a so-called “landscape of fear.”

Why we funded this project

We are interested in the development and validation of the gut microbiome as a welfare indicator. Every additional indicator strengthens the interpretation of others, but understanding the gut microbiome may be especially important because it is part of the causal chain linking what is going on in the animal’s brain to fecal metabolites, which are often analyzed as a non-invasive and time-integrated record of physiological stress. This project also links and builds on other gut microbiome research we have funded (by Melissa Bateson, Pablo Capilla-Lasheras, and Davide Dominoni).

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Assessing the Welfare of Wild Olive Baboons (Papio anubis) at the Uaso Ngiro Baboon Project, Laikipia, Kenya

Grantee: Monica Wakefield

Institutions: Northern Kentucky University and Iowa State University, United States

Grant amount: $29,800

Grant type: Small grants

Focal species: Wild olive baboon (Papio anubis)

Conservation status: Least concern

Disciplines: Animal welfare science, animal behavior, primatology

Research location: Kenya, United States

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Project summary

This project aims to assess the welfare of wild baboons using a holistic approach. The study takes advantage of almost 40 years of long-term ecological, demographic, health, and behavioral information on >170 individually known baboons, and will examine how various factors such as age, sex, and social rank correlate with individual welfare measures such as incidence of injury and disease, body mass, and pro-social or agonistic behaviors. The annual scale of the dataset will also enable the researchers to test how events such as droughts have affected welfare during specific periods, and how these effects may have varied according to individual animals’ demographic profiles and biographies.

Why we funded this project

We are excited by this project’s analysis of a long-term longitudinal dataset because of the importance of understanding how wild animals’ welfare varies with demographic factors such as age and sex, as these groups often face different challenges and have different ecological and behavioral requirements, and negative welfare impacts that fall on young individuals may also have ripple effects throughout their lives. We also appreciate this project’s holistic approach. The long-term monitoring means it is possible to consider not only the usual downstream welfare indicators based on health and behavior, but also upstream factors that might influence them, such as social interactions and exposure to predators.

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Assessing the anthropogenic impacts, long-term health, and welfare of elasmobranch species within San Francisco Bay, California

Grantee: Meghan Holst

Institution: University of California, Davis, United States

Grant amount: $19,200

Grant type: Small grants

Focal species: Shark (Selachimorpha sp.)

Conservation status: Near threatened

Disciplines: Animal welfare science, population ecology, community ecology, marine biology, ichthyology

Research location: United States

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Project summary

Individuals belonging to several elasmobranch populations use the San Francisco Bay Estuary during critical periods of their life history. For example, the broadnose sevengill shark (Notorynchus cepedianus) is an apex predator that visits seasonally to pup. Pups then appear to reside in the estuary for several years before they join the adult population that migrates from Alaska to Baja, California. The San Francisco Bay also serves as a major harbor for container and cruise ships. To allow these large vessels to enter the bay, dredging occurs continuously within San Francisco Bay in the primary channel where many of the adult elasmobranchs also reside, potentially increasing contaminant exposure. Additionally, both commercial and recreational fishing occurs on shark species and their preferred prey, posing direct physiological impacts on elasmobranchs and constraints to their prey availability. Little has been done to evaluate potential unrecognized consequences of these activities on the health and welfare of elasmobranch species and the San Francisco Bay ecosystem. To address this gap in knowledge, this project will measure stress physiology and blood contaminants to evaluate whether the health and welfare of elasmobranchs is threatened within San Francisco Bay, and evaluate dietary needs of elasmobranch species within San Francisco Bay to determine whether individuals are threatened with hunger/starvation due to fishing of their preferred prey. Stable isotope analysis of the sharks and potential prey will also be used to more precisely identify their dietary needs and sensitivities, and ultimately map ecological relationships within the ecosystem.

Why we funded this project

We funded this project primarily because it addresses our interest in understanding the welfare implications of ecological system dynamics. The project also focuses on lifestage-specific ecological differences within the focal species, focusing on juveniles, which are the most numerous and often neglected. Additionally, the lead researcher is a PhD student who has an interest in wild animal welfare and has already demonstrated an aptitude for coordinating scientific research projects. The ability to write a compelling proposal at such an early research stage is very promising for their future career prospects.

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The animal welfare of animal warfare: how inter-group interactions affect wild animal wellbeing

Grantee: Dominic Cram

Institution: University of Cambridge, United Kingdom

Grant amount: $29,965

Grant type: Small grants

Focal species: Meerkats (Suricata suricatta)

Conservation status: Least concern

Disciplines: Animal behavior, population ecology, community ecology

Research location: United Kingdom, South Africa

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Project summary

Fierce group conflicts are not uniquely human, and many group-living animals regularly engage in “animal warfare.” These inter-group interactions play an influential role in natural population regulation, yet the health and well-being consequences for those involved remain unclear. Conservation and management interventions are currently developed with little understanding of how large-scale conflict affects welfare in wild animals. Given that anthropogenic habitat loss and climate change could increase the frequency of inter-group battles, there is an urgent need to investigate the welfare cost of animal warfare. This research program will investigate the welfare consequences of intergroup interactions and fights in wild Kalahari meerkats (Suricata suricatta). The project will take advantage of an established dataset of meerkat behavior, body weight, territory use, and reproduction, covering more than 500 inter-group interactions over 14 years. Identifying the short- and long-term welfare implications of inter-group interactions in meerkats will shed light on similar animal warfare in group-living insects, fish, birds, and mammals. Clarifying the circumstances that lead to the most harmful battles will provide a first step in understanding how their frequency could be reduced, which could limit the suffering they cause and enhance the welfare of group-living wild animals.

Why we funded this project

This project addresses a neglected topic related to our research priority of understanding conflicts of interest between wild animal groups. We especially appreciate this project’s holistic approach to welfare assessment, its attention to indirect effects (collateral damage) of animal conflicts in the form of costs to orphaned juveniles and the creation of a “landscape of fear,” and the openness of the investigators to considering interventions that could elevate wild animal welfare above its natural baseline.

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Physiological and behavioral effects of nicarbazin on feral urban pigeons (Columba livia)

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

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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.

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Development of novel measures of welfare in juvenile European starlings exposed to nutritional stress

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

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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

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

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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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Development of octopus mind in the wild: a behavioral, ecological and evolutionary investigation into sentience and emotional states in Octopus insularis juveniles

Grantee: Michaella Andrade

Institution: Federal University of ABC, Brazil

Grant amount: $37,959

Grant type: Challenge grants

Focal species: Octopuses (Octopoda sp.)

Conservation status: Data deficient

Disciplines: Sentience, animal behavior

Research location: Brazil

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Publications

Andrade M.P., et al. (2023). Assessing Negative Welfare Measures for Wild Invertebrates: The Case for Octopuses. Animals, 13(19), 3021. https://doi.org/10.3390/ani13193021

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Project summary

Welfare refers to the quality of life of animals that possess sentient capacity and emotional states. Although the precursors of sentience were possibly present on the planet as early as 890 million years ago, the evolution of sentience is still poorly understood. However, cephalopods are increasingly being recognized as sentient, yet we do not know about this phenomenon in juvenile wild animals. In this sense, studies with wild animals can be beneficial for finding a wider range of ecological triggers and their relationship with behaviors.

There’s evidence that evolutionary pressures can cause behaviors with opposite meanings to eventually develop opposite forms, the way a frown is the opposite of a smile. One way to understand the expression of emotion in animals therefore may be to find pairs of behaviors that are opposites. In octopus, colors can be a signal of emotional valence during conflict and other contexts. Although researchers began to see this dimension in octopuses, no study has tested whether opposite pairs of color signals are present in octopuses. This project will produce descriptions of evolutionary and behavioral patterns that reflect the emotional states and sentience for juvenile octopuses, which may contribute to the welfare of octopuses and other invertebrates.

Why we funded this project

Although octopuses are widely assumed to be sentient at the adult stage, no studies that we are aware of have examined sentience at earlier life stages. As the vast majority of octopuses alive at any one time are juveniles, and octopuses have enormously high juvenile mortality, the question of when in their development sentience arises is particularly important. This project is also interesting because it will teach us about what the lives of juvenile octopuses are like and the extent to which welfare effects are mediated by personality traits.

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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, 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

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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, 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

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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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