Biology subjects

Griffin, L. L.

Publications and source records attributed to Griffin, L. L..

6 recordsLinked to original sources

bioRxiv2024

Random subsamples of animal populations can reveal intrinsic differences in sociality with key implications in ecology, conservation and disease transmission

Animal populations are under mounting stress from the dual threats of climate change and rapid global human population growth, raising significant concerns about declining wildlife and the rising risk of zoonotic diseases. In many species, social interactions can be a highly plastic suite of behaviours that are responsive to these disturbances and are consequential to other processes like disease transmission and population dynamics. Studying social interactions can be challenging in that researchers often rely on wildlife population subsamples due to practical constraints and costs, which can introduce biases in the reliability of social network metrics. We investigated the extent to which subsamples can depict intrinsic characteristics of wildlife populations using data from three distinct species: peri-urban fallow deer, Alpine ibex and Angolan giraffe. We showed that random subsamples of these populations could still reveal differences in their social behaviour, indicating that, as long as researchers have a reliable estimate of population size, subsampling animal populations can be an effective and precise method to infer their sociality and offer valuable empirical data for management, conservation and zoonotic disease ecology. Furthermore, we demonstrate that non-random sampling, influenced for instance by animal personality and related trappability, can introduce significant biases in social network estimates. These findings underscore the importance of accounting for sampling biases in social network analysis and offer a robust framework for using partial networks in ecological studies and conservation management.

ecology↗

bioRxiv2024

Vulnerable caribou and moose populations display contrasting responses to mountain pine beetle outbreaks and management.

O_LIRising global temperatures and changing landscape conditions have led to widespread mountain pine beetle (MPB) outbreaks in western North America. Extensive management has been implemented in response, via forest harvesting and prescribed burning. However, the impacts of MPB and MPB-management on ungulate populations, particularly caribou and moose, remain poorly studied. Given the differing specialisations of these species (caribou are habitat specialists, moose are generalists), their responses to these disturbances may vary. This could, in turn, lead to unintended, indirect effects (e.g., disturbance-mediated apparent competition, whereby increased moose presence results in increased predator presence, with resultant caribou declines). Unravelling these responses is crucial for informing MPB management and ensuring that applied actions do not exacerbate adverse effects. C_LIO_LIWe assessed the effects of early-stage MPB-infestation, harvest, and fire, on habitat selection by caribou (boreal and central mountain designatable units) and moose in west-central Alberta. We built resource selection functions and functional response models using GPS collar data collected 3-5 years after MPB infestation and found that responses varied between species. C_LIO_LICaribou had complex seasonal responses to MPB, generally avoiding areas with more MPB disturbance in winter but using them in summer. Caribou typically avoided harvested and burned areas, though this was dependent on the overall degree of disturbance within their ranges. In contrast, moose had positive responses to both MPB and burned areas year-round. C_LIO_LIThese findings suggest that MPB may negatively impact long-term winter habitat availability for threatened caribou populations, but may have positive impacts on moose habitat. However, moose use of MPB-impacted areas could further affect caribou by contributing to disturbance-mediated apparent competition. C_LIO_LISynthesis and applications: The negative impacts of forest harvest and burning on caribou suggests that less intensive actions are required for MPB management within caribou ranges.. While moose selectively used harvested and burned areas, it is possible that they may have adverse responses to cumulative disturbance over time. As caribou and moose responded to MPB soon after infestation, ongoing monitoring is required to detect MPB early and facilitate proactive management, though further study is needed to determine the most effective actions. C_LI

ecology↗

bioRxiv2024

Fallow deer approaching humans are also more likely to be seropositive for Toxoplasma gondii.

Toxoplasma gondii (T. gondii) is a trophically-transmitted protozoan parasite that has been suggested to facilitate its transmission by altering intermediate hosts anti-predator behaviour, thus increasing the likelihood of completing the cycle inside its definitive host i.e. domestic and wild felines. T. gondii has been linked to reduced risk-aversion, slower reaction times, and more exploratory behaviours in intermediate hosts, including most famously weakened aversion to the scent of feline predators in mice. Studies examining this phenomenon, however, have almost exclusively been carried out in laboratory conditions with small mammals, whereas little is known about the role of T. gondii within more complex ecological contexts involving large mammals in the wild. Under such scenario, the goals of our study were three-fold. Firstly, to determine the prevalence of T. gondii infection in a population of free-living fallow deer (Dama dama) living in a park at the edge of a metropolis. Secondly, to find a link between deer seropositivity and space use in the park, namely proximity to buildings with domestic cats, where deer may have been more likely to contract the disease. Finally, to determine whether infection with T. gondii was linked to risk taking behaviour in these free ranging large mammals, namely likelihood to approach park visitors. To achieve our goals, we estimated seropositivity and combined it with spatial distribution and behavioural data of individually-recognizable deer ranging from those that avoid humans (risk-avoiders) to those who beg for food (risk-takers). We found T. gondii to be quite widespread in this population with a seropositive of 20% (24 out of 120 individuals). Contrary to our expectations, we found no correlation between T. gondii seropositivity and space use in the park, therefore not allowing us to engage with the dynamics of disease contraction. We did however find that fallow deer taking the risk of approaching humans were also more likely to be seropositive. Are risk taking individuals more likely to contract the disease? Or, alternatively, do they take more risk because they have contracted the disease? The causal mechanism behind our result has yet to be disentangled, opening new scenarios in research aimed at tackling host manipulation in this parasite. It is a fact, however, that those animals that were more likely to be in contact with the public were also those more likely to be seropositive, adding key empirical evidence to the study of zoonotic diseases. Our study is a significant contribution on the transmission and maintenance dynamics of T. gondii, offering new insights on the need to conduct longitudinal studies able to disentangle the causal mechanism and T. gondiis ability to manipulate its intermediate host.

animal behavior and cognition↗

bioRxiv2023

Does fear of humans predict anti-predator strategies in an ungulate hider species during fawning?

Humans are a major evolutionary force on wildlife via artificial selection. While often explored through the lens of extractive interactions (e.g., hunting) able to favour certain behavioural traits over others, the implications of non-extractive ones, such as wildlife feeding, remain under-studied. Research has recently shown that people tend to feed (and sometimes favour) a limited subset of bolder individuals within natural populations, although its dynamics and consequences are not fully clear. Using fallow deer living in a peri-urban setting as a model population, we studied whether mother deer that display reduced fear of humans and consistently approach them for food adopt weaker anti-predator strategies by selecting for fawning bedsites that are less concealed and closer to human hotspots, allowing them to take advantage of additional artificial feeding opportunities in comparison to shier mothers in this population. Our dataset encompassed 171 fawns from 109 mothers across 4 years. Contrary to our expectations, we found that mothers that regularly accepted food from humans selected for more concealed bedsites farther away from them, giving their offspring better protection while also taking advantage of additional artificial food during lactating. Our results show marked behavioural adaptation by a subset of females, making this the first time that the link between tendency to approach humans and strategies to protect offspring is explored. Given previous findings that these begging females also deliver heavier fawns at birth, our research adds a piece to the complex puzzle describing human manipulation of behaviour in natural populations and its fitness consequences.

animal behavior and cognition↗

bioRxiv2023

Fawn bedsite selection by a large ungulate living in a peri-urban area

Human-wildlife conflict in expanding peri-urban and urban areas is of increasing concern, as a result of growing human populations along with the associated anthropogenic footprint on wildlife habitats. Empirical data from wildlife research carried out within human dominated landscapes are key to understanding the effects of human pressures on wildlife ecology and behaviour, exploring wildlife behavioural flexibility (or phenotypic plasticity), and informing wildlife management decisions. Here, we explored how female fallow deer (Dama dama) responded to human and dog presence during the birthing period in the largest walled urban park in Europe. We collected data on 477 bedsites utilised by 283 neonate fawns across three consecutive fawning seasons, gathered fine-scale data on humans and dogs space use, and built Resource Selection Functions at multiple spatial scales. We found that, when choosing bedsites to give birth and leave fawns unattended, fallow deer mothers significantly avoided hotspots of park visitors on foot (and their dogs) along the hiking trail routes. Bedsites were also unlikely to be in close proximity of paved roads used by vehicle traffic. Additionally, fallow deer mothers were found to select for dense understory vegetation for bedsites, providing low visibility to conceal their offspring. Our results provide detailed insights into bedsite spatial and habitat selection by a large herbivore in response to human activities, and we provide clear indications to wildlife managers to preserve established fawning sites and alleviate human-wildlife conflict during a critical period of the deer annual biological cycle.

animal behavior and cognition↗

bioRxiv2023

Curbing zoonotic disease spread in multi-host-species systems will require integrating novel data streams and analytical approaches: evidence from a scoping review of bovine tuberculosis

BackgroundZoonotic diseases represent a significant societal challenge in terms of their health and economic impacts. One Health approaches to managing zoonotic diseases are becoming more prevalent, but require novel thinking, tools and cross-disciplinary collaboration. Bovine tuberculosis (bTB) is one example of a costly One Health challenge with a complex epidemiology involving human, domestic animal, wildlife and environmental factors, which require sophisticated collaborative approaches. ObjectiveWe undertook a scoping review of multi-host bTB epidemiology to identify recent trends in species publication focus, methodologies, scales and One Health approaches. We aimed to identify research gaps where novel research could provide insights to inform control policy, for bTB and other zoonoses. ResultsThe review included 167 articles. We found different levels of research attention across episystems, with a significant proportion of the literature focusing on the badger-cattle-TB episystem, with far less attention given to the multi-host episystems of southern Africa. We found a limited number of studies focusing on management solutions and their efficacy, with very few studies looking at modelling exit strategies. Surprisingly, only a small number of studies looked at the effect of human disturbances on the spread of bTB involving wildlife hosts. Most of the studies we reviewed focused on the effect of badger vaccination and culling on bTB dynamics with few looking at how roads, human perturbations and habitat change may affect wildlife movement and disease spread. Finally, we observed a lack of studies considering the effect of weather variables on bTB spread, which is particularly relevant when studying zoonoses under climate change scenarios. ConclusionsSignificant technological and methodological advances have been applied to bTB episystems, providing explicit insights into its spread and maintenance across populations. We identified a prominent bias towards certain species and locations. Generating more high-quality empirical data on wildlife host distribution and abundance, high-resolution individual behaviours and greater use of mathematical models and simulations are key areas for future research. Integrating data sources across disciplines, and a "virtuous cycle" of well-designed empirical data collection linked with mathematical and simulation modelling could provide additional gains for policy-makers and managers, enabling optimised bTB management with broader insights for other zoonoses.

ecology↗