Laurel Serieys - Academia.edu (original) (raw)

Papers by Laurel Serieys

Environmental Pollution

Recent studies have suggested that plastic contamination in some terrestrial and freshwater envir... more Recent studies have suggested that plastic contamination in some terrestrial and freshwater environments is estimated to be greater than that detected in marine environments. Urban wetlands are prone to plastic pollution but levels of contamination in their wildlife are poorly quantified. We collected 276 fishing cat (Prionailurus viverrinus) scat samples in Colombo, Sri Lanka for a dietary study of urban fishing cats. We used traditional dietary analysis methodology to investigate the contents of the scats by washing, isolating, and identifying prey remains; while sorting prey remains of individual scats, we unexpectedly detected macroscopic (>1 mm) plastic debris in six (2.17%) of the samples. Across all scat samples, we detected low occurrences of microplastics (0.72%), mesoplastics (1.09%) and macroplastics (1.45%). All three plastic types were found in scats containing rodent remains, while meso-, and macroplastics were found in scats with avian remains, and micro- and macroplastics in scats containing freshwater fish remains. Given that felids are obligate generalist carnivores that eat live or recently dead prey and do not consume garbage, our findings suggest that trophic transfer of plastics occurred whereby fishing cats consumed prey contaminated with plastic. Although macroscopic plastic detection was low, our findings suggest that accumulation of plastics is occurring in wetland food webs, and plastic pollution in freshwater terrestrial systems could pose a risk to predators that do not directly consume plastics but inhabit contaminated environments.

Genes

We used mitochondrial sequences and nuclear microsatellites to investigate population structure o... more We used mitochondrial sequences and nuclear microsatellites to investigate population structure of gray foxes (Urocyon cinereoargenteus) and the evolutionary origins of the endemic island fox (Urocyon littoralis), which first appeared in the northern Channel Islands <13,000 years ago and in the southern Channel Islands <6000 years ago. It is unclear whether island foxes evolved directly from mainland gray foxes transported to the islands one or more times or from a now-extinct mainland population, already diverged from the gray fox. Our 345 mitochondrial sequences, combined with previous data, confirmed island foxes to be monophyletic, tracing to a most recent common ancestor approximately 85,000 years ago. Our rooted nuclear DNA tree additionally indicated genome-wide monophyly of island foxes relative to western gray foxes, although we detected admixture in northern island foxes from adjacent mainland gray foxes, consistent with some historical gene flow. Southern California...

Mammalian Biology, 2021

Urbanisation and habitat loss are major threats to wildlife populations globally. Understanding h... more Urbanisation and habitat loss are major threats to wildlife populations globally. Understanding how species respond to anthropogenic changes is therefore crucial to mitigating threats and developing conservation management strategies. We examined the habitat use of five fishing cats ( Prionailurus viverrinus ) in Sri Lanka’s capital city, Colombo, a densely urbanised landscape with a mosaic of wetland habitats, cultivated areas, and altered open spaces. We investigated: (1) to what extent all five cats used human-impacted versus natural wetland habitat; (2) whether there were behavioural shifts to avoid human activity throughout the diel cycle; (3) the home range sizes of two resident females and one resident male, and the extent of the area used by the two translocated males; (4) whether the two translocated males would survive introduction to a new urban environment. We monitored the fishing cats for 637 days (mean = 127) and collected a total of 2278 GPS (5-h interval) collar locations. We found that all five individuals used highly urbanised areas more than we expected. Home range sizes of the three residents were smaller than fishing cat home ranges in less disturbed landscapes. Though our sample size was small, our findings suggest that fishing cats use urbanised areas in Colombo, particularly at night, likely to avoid daytime human activity. Further comprehensive ecological study is needed to explore the aspects of fishing cat ecology that facilitate their persistence, and aid in their conservation across increasingly urbanised areas.

File contains Gene Symbol, linear model coefficients and q-values, and WGCNA module assignment

File includes summaries of data processing (sequence counts data), and metadata (technical and bi... more File includes summaries of data processing (sequence counts data), and metadata (technical and biological traits) for each bobcat

This file contains the raw HT-seq read counts generated from raw fastq sequence reads after align... more This file contains the raw HT-seq read counts generated from raw fastq sequence reads after alignment to the domestic cat genome. The first two columns include the mean GC content and mean gene length for all genes, which were used for filtering and normalization

Anticoagulant rodenticides (ARs) are indiscriminate toxicants that threaten non-target predatory ... more Anticoagulant rodenticides (ARs) are indiscriminate toxicants that threaten non-target predatory and scavenger species through secondary poisoning. Accumulating evidence suggests that AR exposure may have disruptive sublethal consequences on individuals that can affect fitness. We evaluated AR-related effects on genome wide expression patterns in a population of bobcats in southern California. We identify differential expression of genes involved in xenobiotic metabolism, endoplasmic reticulum stress response, epithelial integrity, and both adaptive and innate immune function. Further, we find that differential expression of immune related genes may be attributable to AR-related effects on leukocyte differentiation. Collectively, our results provide an unprecedented understanding of the sublethal effects of AR exposure on a wild carnivore. These findings highlight potential detrimental effects of ARs on a wide variety of species worldwide that may consume poisoned rodents and indicate the need to investigate gene expression effects of other toxicants added to natural environments by humans

Animal ID with capture date, season, AR and disease status, and health parameters

Understanding how human activities influence immune response to environmental stressors can suppo... more Understanding how human activities influence immune response to environmental stressors can support biodiversity conservation across increasingly urbanizing landscapes. We studied a bobcat (Lynx rufus) population in urban southern California that experienced a rapid population decline from 2002–2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological variables was primarily associated with AR exposure and secondarily with urbanization. Use of urban habitat and AR exposure has pervasive, complex and predictable effects on biochemical markers of immune and organ function in free-ranging bobcats that include impacts on neutrophil, lymphocyte and cytokine populations, total bilirubin and phosphorus. We find evidence of both inflammatory response and immune suppression associated with urban land use and rat poison exposure that could influence susceptibility to opportunistic infections. Consequently, AR exposure may influence mortality and has population-level effects, as previous work in the focal population has revealed substantial mortality caused by mange infection. The secondary effects of anticoagulant exposure may be a worldwide, largely unrecognized problem affecting a variety of vertebrate species in human-dominated environments

The extinction vortex is a theoretical model describing the process by which extinction risk is e... more The extinction vortex is a theoretical model describing the process by which extinction risk is elevated in small, isolated populations owing to interactions between environmental, demographic, and genetic factors. However, empirical demonstrations of these interactions have been elusive. We modelled the dynamics of a small mountain lion population isolated by anthropogenic barriers in greater Los Angeles, California, to evaluate the influence of demographic, genetic, and landscape factors on extinction probability. The population exhibited strong survival and reproduction, and the model predicted stable median population growth and a 15% probability of extinction over 50 years in the absence of inbreeding depression. However, our model also predicted the population will lose 40–57% of its heterozygosity in 50 years. When we reduced demographic parameters proportional to reductions documented in another wild population of mountain lions that experienced inbreeding depression, extinction probability rose to 99.7%. Simulating greater landscape connectivity by increasing immigration to greater than or equal to one migrant per generation appears sufficient to largely maintain genetic diversity and reduce extinction probability. We provide empirical support for the central tenet of the extinction vortex as interactions between genetics and demography greatly increased extinction probability relative to the risk from demographic and environmental stochasticity alone. Our modelling approach realistically integrates demographic and genetic data to provide a comprehensive assessment of factors threatening small populations

Science of The Total Environment, 2022

Wildlife around cities bioaccumulate multiple harmful environmental pollutants associated with hu... more Wildlife around cities bioaccumulate multiple harmful environmental pollutants associated with human activities. Exposure severity can vary based on foraging behaviour and habitat use, which can be examined to elucidate exposure pathways. Carnivores can play vital roles in ecosystem stability but are particularly vulnerable to bioaccumulation of pollutants. Understanding the spatial and dietary predictors of these contaminants can inform pollutant control, and carnivores, at the top of food webs, can act as useful indicator species. We test for exposure to toxic organochlorines (OCs), including dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), in a medium-sized felid, the caracal (Caracal caracal), across the peri-urban and agricultural landscapes of the city of Cape Town, South Africa. Concentrations in both blood (n = 69) and adipose tissue (n = 25) were analysed along with detailed spatial, dietary, demographic, and physiological data to assess OC sources and exposure risk. The analysis revealed widespread exposure of Cape Town's caracals to organochlorines: detection rate was 100% for PCBs and 83% for DDTs in blood, and 100% for both compounds in adipose. Caracals using human-transformed areas, such as vineyards and areas with higher human population and electrical transformer density, as well as wetland areas, had higher organochlorine burdens. These landscapes were also highly selected foraging areas, suggesting caracals are drawn into areas that co-incidentally increase their risk of exposure to these pollutants. Further, biomagnification potential was higher in individuals feeding on higher trophic level prey and on exotic prey. These findings point to bioaccumulation of OC toxicants and widespread exposure across local food webs. Additionally, we report possible physiological effects of exposure, including elevated white blood cell and platelet count, suggesting a degree of immunological response that may increase disease susceptibility. Cape Town's urban fringes likely represent a source of toxic chemicals for wildlife and require focused attention and action to ensure persistence of this adaptable mesocarnivore.

Regression plots for select parameters significantly associated with land use.

Animal Conservation, 2021

As natural habitat is progressively transformed, effective wildlife conservation relies on unders... more As natural habitat is progressively transformed, effective wildlife conservation relies on understanding the phenotypic traits that allow select species to persist outside of protected areas. Through behavioural flexibility such species may trade off abundant resources with risks, both real and perceived. As highly adaptable mesocarnivores, caracals (Caracal caracal) provide an opportunity to examine development of successful foraging strategies in high‐risk developed areas. Here we investigated caracal resource selection of both anthropogenic and environmental factors relative to availability at varying levels of urbanization in and around the city of Cape Town, South Africa, using GPS cluster‐located feeding events (n = 326 prey remains, n = 384 scat). We also examined spatial and temporal risk mitigation strategies by assessing behaviours at feeding clusters. We find that, within home ranges, caracals living in the urban‐dominated region (n = 14; 548 feeding events) select for the urban edge, while caracals in the wildland‐dominated region (n = 3; 162 feeding events) avoid it. Adults selected more strongly for foraging at the urban edge than juveniles and may competitively exclude them from resources. By including back‐traced scat feeding event locations, we were able to improve model resolution. We argue that caracals foraging on the edge of a large metropole mitigate risk of detection by remaining cryptic, prolonging handling time, and maintaining high feeding site fidelity where cover was available. Along with the strong functional response to the urban edge, this strategy suggests that carnivores are being drawn into, and stay longer in, areas with potentially increased prey availability despite higher risk. While behavioural plasticity clearly enables carnivore coexistence with humans in urban ecosystems, it can also be maladaptive if it reduces fitness and leads the population into an ecological trap. We provide mitigative recommendations to promote the conservation of this predator in a spatially isolated and rapidly urbanizing landscape.

Wildlife populations are increasingly challenged by human activities that disrupt landscape conne... more Wildlife populations are increasingly challenged by human activities that disrupt landscape connectivity, animal movement, population dynamics and population persistence. Yet modified habitats may provide resource subsidies for generalist species resulting in increased selection of disturbed areas. Understanding how species adjust their space use and activity in human-modified landscapes is fundamental to conserving wildlife populations globally. To test three competing hypotheses explaining spatiotemporal responses to human activity, we investigated coarse (3 hour)- and fine (20 minute)- scale habitat selection, activity patterns, and measured home ranges in a human-dominated landscape. We GPS-collared 25 adults and subadult caracals (Caracal caracal) from three contiguous subpopulations in urban and wildland-dominated regions. Caracals in the wildland-dominated region avoided proximity to urban areas while caracals in the urban-dominated region selected for close proximity to urba...

Virology, 2021

Anellovirus infections are highly prevalent in mammals, however, prior to this study only a handf... more Anellovirus infections are highly prevalent in mammals, however, prior to this study only a handful of anellovirus genomes had been identified in members of the Felidae family. Here we characterise anelloviruses in pumas (Puma concolor), bobcats (Lynx rufus), Canada lynx (Lynx canadensis), caracals (Caracal caracal) and domestic cats (Felis catus). The complete anellovirus genomes (n = 220) recovered from 149 individuals were diverse. ORF1 protein sequence similarity network analysis coupled with phylogenetic analysis, revealed two distinct clusters that are populated by felid-derived anellovirus sequences, a pattern mirroring that observed for the porcine anelloviruses. Of the two-felid dominant anellovirus groups, one includes sequences from bobcats, pumas, domestic cats and an ocelot, and the other includes sequences from caracals, Canada lynx, domestic cats and pumas. Coinfections of diverse anelloviruses appear to be common among the felids. Evidence of recombination, both within and between felid-specific anellovirus groups, supports a long coevolution history between host and virus.