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), 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

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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.

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Predicting density dependence of welfare of wild animal populations based on resource access linked to habitat availability and usage

Grantee: Ross MacLeod

Institutions: Liverpool John Moores University, United Kingdom

Grant amount: $159,744

Grant type: Challenge grants

Focal species: House sparrow (Passer domesticus)

Conservation status: Least concern

Disciplines: Ecological modeling, population ecology, animal welfare science

Research location: United Kingdom

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Project summary

This project seeks to adapt a habitat and population model to incorporate welfare and apply it to the study of an abundant and widespread avian species, the house sparrow (Passer domesticus). The researchers propose to utilize a variety of welfare metrics to validate model assumptions, which will then allow them to test assumptions related to the welfare implications of density-dependent population dynamics.

Why we funded this project

We funded this project because it addresses our proposal request very closely and proposes to investigate a key wild animal welfare question using a modeling framework. They are also planning to address their question using an abundant avian species. The project has high potential to inform future work focused on modeling total welfare in a population (i.e., combining both individual welfare and population size), and to create a model that can be replicated in other systems.

Find Ross’ other project, studying wild birds, here.

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Thermal imaging as a non-invasive welfare assessment tool for tracking the impact of environmental stressors across wild animal populations

Grantee: Ross MacLeod

Institution: Liverpool John Moores University, United Kingdom

Grant amount: $29,810

Grant type: Small grants

Focal species: Wild birds

Conservation status: Least concern

Disciplines: Physiology, animal welfare science, population ecology, ornithology

Research location: United Kingdom

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Project summary

This project aims to test and validate a standardized multi-species approach to monitoring physiological stress in wild birds by using thermal imaging cameras to measure the animals’ body surface temperature, which could enable tracking of chronic stress in wild populations facing different levels of environmental stressors. Building on pilot work, the project will focus on wild bird populations to develop a standardized thermal imaging methodology capable of monitoring surface temperature of a wide range of free-living wild animals. The methodology will be validated using bird communities visiting 54 standardized feeding and drinking stations spread across three urban-rural gradients in the UK, to quantify how changes in surface temperature are linked to starvation risk, predation risk, and human disturbance.

Why we funded this project

This approach to measuring wild animals’ physiological stress levels through thermal imaging analysis has great potential for scalable monitoring of large numbers of individuals and is usable for cross-species comparisons. We appreciated that this team was interested in addressing non-anthropogenic causes of suffering in starvation and predation, and in extending their method to other species that tend to be neglected (e.g., wild rodents). This work also relates to the project by Paul Jerem that we previously funded, creating a longer-term relationship between Wild Animal Initiative and project participants.

Find Ross’ other project, studying house sparrows, here.

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Novel epigenetic approaches to measure wild animal welfare and stress

Grantee: Dave Daversa

Institution: University of California, Los Angeles, United States

Grant amount: $30,000

Grant type: Small grants

Focal species: Western toad (Anaxyrus boreas)

Conservation status: Least concern

Disciplines: Physiology, herpetology, animal welfare science, population ecology, genetics/genomics

Research location: United States

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Project summary

A major challenge in wild animal welfare science lies in developing composite assays that consider the full breadth of factors collectively shaping the subjective experiences of animals. This project will apply epigenetic tools to develop minimally invasive and aggregate measures of wild animal welfare. Specifically, the researchers aim to demonstrate proof of concept for a DNA methylation (DNAm)-based model of wild animal welfare. DNAm joins other measurements such as telomere attrition as a biomarker of biological aging, because DNA becomes methylated as a function of both chronological age (time) and accumulated stress. This project will characterize DNAm in western toads (Anaxyrus boreas) from wild populations in southern California, testing the influence of infection with the fungal pathogen Batrachochytrium dendrobatidis (Bd) on DNAm, and its covariance with demographic factors such as age and sex, as well as with body condition, a common metric of physical health in wild animals. Captive-reared toads representing all life stages will be sampled to characterize DNAm under controlled conditions, providing a standardized profile of DNAm rates over toad life stages. The researchers will then sample toads from wild populations experiencing starkly different levels of environmental stress (Bd infection), with accelerated biological aging signaling elevated stress and impaired welfare. 

Project objectives

Objective 1: Determine the relationship between DNAm and basic risk factors linked to welfare: chronological age, sex, weight, and infection status.

Objective 2: Determine the effect of environmental stressors on epigenetic age.

Why we funded this project

We funded this project because we are interested in the potential for biological aging biomarkers to be used as very long-term, integrative metrics of animals’ lifetime welfare. DNAm is one such potential biomarker that has received relatively little attention in a welfare context. However, DNAm may potentially be easier to measure than more commonly discussed measures of biological age — or at least, be more familiar for mainstream ecological genetics researchers — because DNA methylation is already of interest for other reasons in biological science. We were particularly enthusiastic about this project because it focuses on a species belonging to a large species complex of amphibians, including both common and threatened species, offering broad transferability and potential impact. Amphibians are also relatively neglected in terms of welfare research. We appreciate that this project aims to establish baseline age-specific differences in biological aging rate in order to then assess age-specific differences attributable to different exposures (i.e., age-specific differences in welfare), which connects to the concept of “welfare expectancy” developed by Wild Animal Initiative researcher Luke Hecht.

Find Dave’s other project, studying western fence lizards, here.

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Developing an approach for assessing the welfare of wild birds through the use of bioacoustics analysis

Grantees: Luiza Figueiredo Passos

Institution: Liverpool John Moores University, United Kingdom

Grant amount: $29,060

Grant type: Small grants

Focal species: House sparrow (Passer domesticus)

Conservation status: Least concern

Disciplines: Animal welfare science, ornithology, population ecology, animal behavior

Research location: United Kingdom

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Project summary

Vocalisations carry emotional, physiological, and individual information, suggesting that they can serve as potentially useful non-invasive indicators for inferring wild animal welfare. Communication of affective states via vocalization is due to changes in emotions leading to deviations in the nervous system, causing physiological changes within the vocal production systems. Modern sound analysis techniques have provided tools to discriminate, analyze, and classify specific vocalizations, permitting them to be used for monitoring welfare of different farm and laboratory animals. However, this approach lacks validation for wild individuals. This proposal aims to use passive acoustic monitoring to record wild bird calls at different locations in urban, rural, and conservation-managed areas in the UK. This project will follow a comparative approach to identify vocal patterns and chorus characteristics related to different environmental risks (starvation risk, predation risk, human disturbance, etc.) so that these vocal signatures can be used to infer the welfare status of local bird populations across different environments. The focal species will be one of Europe’s most common species, the house sparrow (Passer domesticus). House sparrows provide an ideal first validation as the species has undergone a massive population decline in many parts of its range over the past 50 years, suggesting that its local populations are facing significant welfare challenges. Validating acoustic monitoring as a tool for non-invasive welfare monitoring in the wild for the first time will provide the basis for future application to birds in general, providing a method that could be used to monitor welfare and changes in welfare of wild birds at any location globally.

Project objectives

Objective 1: Evaluate how changes in sparrow welfare driven by changes in risk of starvation can be indicated by changes in the vocal signatures of local populations.

Objective 2: Understand relationship between predation risk driven changes in sparrows’ welfare and the vocal signatures of local populations.

Objective 3: Impact of human disturbance on sparrows’ welfare.

Why we funded this project

This project is very similar to projects by Claudia Wascher and Sam Reynolds. As stated, bioacoustic monitoring is an extremely promising approach because it is minimally invasive and inexpensive. However, it still needs to be validated, and given its potential future value, we felt that it would be best for it to be validated by at least two independent studies. This project was especially appealing because it focuses on such a ubiquitous species (the house sparrow) and is led by a researcher with a strong record in bioacoustics and an understanding of animal welfare science.

Find Luiza’s other project, studying wild newts, here.

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Assessing animal welfare from bioacoustic monitoring in red-billed choughs (Pyrrhocorax pyrrhocorax)

Grantees: Claudia Wascher

Institution: Anglia Ruskin University, United Kingdom

Grant amount: $18,679

Grant type: Small grants

Focal species: Red-billed chough (Pyrrhocorax pyrrhocorax)

Conservation status: Least concern

Disciplines: Animal welfare science, ornithology, population ecology, animal behavior

Research location: United Kingdom

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Project summary

In principle, animal vocalizations can be used to identify both positive and negative experiences. Specific vocal characteristics (e.g., mean fundamental frequency) and the rate of occurrence of certain call types can help to quantify animal welfare and are well-established in farm animals such as pigs, horses, cows, and chickens. But although bioacoustic monitoring is a well-established method in captive animals, the method has not been used in wild animals to assess positive and negative emotional states. This project will assess and validate the use of passive bioacoustic monitoring to assess welfare in a reintroduced population of red-billed choughs. The researchers will conduct a combination of automatic acoustic monitoring using “passive” acoustic recorders and direct observations (recording behavior via videos, monitoring activity during the night with night vision scopes, and “active” acoustic monitoring using high-quality directional microphone and parabolic dish). Their approach will allow them to record vocalizations and behavior during natural events expected to influence welfare, such as anthropogenic noise, predation events, intraspecific aggression, resting, or affiliative behaviors. 

Why we funded this project

This project will help to validate the use of passive acoustic monitoring to assess welfare states from variation in vocal behavior, which presents a non-invasive, cost-effective tool to assess the impact of positive and negative events on animal welfare. In theory, acoustic monitoring could be used to assess the welfare of a large number of individuals at a time, making it a particularly promising method to investigate.

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Impacts of land-use on social networks in mixed-species bird flocks, with implications for the short-term and long-term welfare of Himalayan birds

Grantee: Akshay Bharadwaj

Institutions: Indian Institute of Science, India

Grant amount: $15,000

Grant type: Small grants

Focal species: Multi-species birds

Conservation status: Least concern

Disciplines: Ornithology, physiology, community ecology, infections disease, population ecology

Research location: India

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Project summary

This project will use mist-netting and bird-banding, followed by standardized observations of behavior and body condition, to examine the relationship between individual-level social behavior, bird health, and survival within mixed-species bird flocks (MSFs) in Eaglenest Wildlife Sanctuary, Arunachal Pradesh, India. Feather corticosterone level, ectoparasite load, and other morphological parameters will be used to measure the health of each banded individual. The researcher will also take advantage of a long-term bird-banding dataset, spanning 12 years, to examine the linkages between inter-individual differences in social behavior and the survival of each individual, comparing survival rates and reproductive success in primary and logged forest. 

Why we funded this project

Understanding the importance of multi-species flocking behavior in birds is relevant to our research priority of understanding indirect welfare effects in ecological systems, which this project approaches in a cost-effective way. We were especially impressed by the quality of the proposal for this project, particularly as it is led by a beginning graduate student in India. Funding this project serves to increase the geographic diversity of our grantee community and therefore of the nascent field of wild animal welfare research.

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From rehabilitation centers to the wild: Evaluating brown bear stress using blood and scat parameters

Grantee: Morteza Naderi

Institution: Koç University, Turkey

Grant amount: $29,955

Grant type: Small grants

Focal species: Brown bear (Ursus arctos)

Conservation status: Least concern

Disciplines: Population ecology, animal welfare science, human-wildlife conflict

Research location: Turkey

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Project summary

Brown bears play a prominent role in the ecosystems of northern and eastern Turkey. However, there are serious long-term threats to their welfare and viability that are common to other large omnivores, such as habitat fragmentation and increasing contact with humans. For example, open garbage dumps are located across the bear’s distribution and affect behavioral patterns in bears, including seasonal migration habits, whereby the bears would normally move into different areas to exploit seasonal resources. This project will involve a collaboration with KuzeyDoga, one of the only nature conservation NGOs in Turkey, to monitor the behavior and stress physiology of individual free-living bears using GPS collars, camera traps, and blood and fecal glucocorticoids (GCs). The location and behavior data will allow them to document what stimuli individual bears have been exposed to (e.g. use of garbage dumps, proximity to roads), and when. This information can then be paired with the GC results to better understand the welfare implications of those exposures. The study of wild bears will also be complemented by the same physiological measurements on bears residing at a rehabilitation center in the region, which come from a similar genetic and early-life background to the free-living bears.

Why we funded this project

This project addresses our objective of validating non-invasive physiological welfare indicators (e.g. fecal GCs) against behavior and known environmental stressors. The pairing of wild and captive (rescued/rehabilitated) individuals is also notable because the captive individuals can serve as a sort of control group due to their controlled environment at the rehabilitation center. Although brown bears in Turkey are not as numerous as some other species we tend to prioritize research on, they and the threats they face are ecologically similar to those faced by most bears worldwide, especially North American black bears, who number many hundreds of thousands. Therefore, we expect the findings of this project to be at least partially generalizable to more than one million potentially long-lived individuals.

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WellSeal: Non-invasive quantification of welfare in lactating harbour seals

Grantee: Jess Harvey-Carroll

Institution: University of Gothenburg, Sweden

Grant amount: $30,000

Grant type: Small grants

Focal species: Harbour seal (Phoca vitulina)

Conservation status: Least concern

Disciplines: Population ecology, animal behavior, animal welfare science

Research location: Sweden

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Project summary

Harbor seals require locations protected from adverse weather and other disturbances during the birthing season, when vulnerable pups are left on land while mothers forage. The limited availability of such sites leads to high intraspecific competition, in which larger seals are likely to dominate more desirable locations due both to their physical strength and their lower need to forage. Mothers must choose when and for how long to forage, leading to trade-offs between maternal and offspring welfare which may lay the foundation for the welfare of younger generations. Currently, little information is available on time spent foraging during the lactation period. As harbor seals are facing unprecedented stress from overfishing, seals are swimming increasingly large distances to obtain food. It is not known how this change affects the trade-off between maternal foraging and offspring care, and the resulting welfare of the pups. This project will use camera trap footage and state-of-the-art 3D modeling to non-invasively assess the influence of maternal welfare on the time spent away from the pups. Pup welfare during periods of maternal absence will also be assessed. Welfare will be assessed in terms of the Five Domains framework, based on individual body condition (health), an index of the optimality of their haul-out position (environment), and a record of positive and negative interactions (behavior). Such welfare assessment will be aggregated at a colony level to compare welfare between colonies with more and less access to food.

Why we funded this project

We funded this project because it seeks to evaluate welfare impacts of population density — likely a common cause of welfare issues — in a relatively abundant species, using a robust approach that is only possible thanks to the species-specific knowledge of the PI and her collaborators. For example, we value their use of image analyses to identify haul-out site suitability and welfare impacts on a fine spatial scale that takes into account both environmental and social factors. We also valued the focus on juvenile welfare and the conflict of interest that may arise between parent and offspring. Improving our understanding of the fundamental relationships between population density, parental care, and juvenile welfare will allow the results of this project to extend to other contexts.

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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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