Dataset Information

Conservation of genetic uniqueness in remaining populations of red squirrels (Sciurus vulgaris L.) in the South of England.

ABSTRACT: The Eurasian red squirrel (Sciurus vulgaris) is an emblematic species for conservation, and its decline in the British Isles exemplifies the impact that alien introductions can have on native ecosystems. Indeed, red squirrels in this region have declined dramatically over the last 60 years due to the spread of squirrelpox virus following the introduction of the gray squirrel (Sciurus carolinensis). Currently, red squirrel populations in Britain are fragmented and need to be closely monitored in order to assess their viability and the effectiveness of conservation efforts. The situation is even more dramatic in the South of England, where S. vulgaris survives only on islands (Brownsea Island, Furzey Island, and the Isle of Wight). Using the D-loop, we investigated the genetic diversity and putative ancestry of the squirrels from Southern England and compared them to a European dataset composed of 1,016 samples from 54 populations. We found that our three populations were more closely related to other squirrels from the British Isles than squirrels from Europe, showed low genetic diversity, and also harbored several private haplotypes. Our study demonstrates how genetically unique the Southern English populations are in comparison with squirrels from the continental European range. We report the presence of four private haplotypes, suggesting that these populations may potentially harbor distinct genetic lineages. Our results emphasize the importance of preserving these isolated red squirrel populations for the conservation of the species.

SUBMITTER: Hardouin EA

PROVIDER: S-EPMC6580283 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Conservation of genetic uniqueness in remaining populations of red squirrels (Sciurus vulgaris L.) in the South of England.

Hardouin Emilie A EA Baltazar-Soares Miguel M Schilling Anna-Katarina AK Butler Helen H García-Rodríguez Oxala O Crowley Eloise E Liang Wei-Jun WJ Meredith Anna A Lurz Peter W W PWW Forster Jane J Kenward Robert E RE Hodder Kathy H KH

Ecology and evolution 20190524 11

The Eurasian red squirrel (Sciurus vulgaris) is an emblematic species for conservation, and its decline in the British Isles exemplifies the impact that alien introductions can have on native ecosystems. Indeed, red squirrels in this region have declined dramatically over the last 60 years due to the spread of squirrelpox virus following the introduction of the gray squirrel (Sciurus carolinensis). Currently, red squirrel populations in Britain are fragmented and need to be closely ...[more]

PMID: 31236243

Similar Datasets

Project description:BackgroundIn September 2014, there was sudden upsurge in the number of Eurasian red squirrels (Sciurus vulgaris) found dead in the Netherlands. High infection levels with the parasite Toxoplasma gondii were demonstrated, but it was unclear what had caused this increase in cases of fatal toxoplasmosis. In the present study, we aimed to gain more knowledge on the pathology and prevalence of T. gondii infections in Eurasian red squirrels in the Netherlands, on the T. gondii genotypes present, and on the determinants of the spatiotemporal variability in these T. gondii infections. The presence of the closely related parasite Hammondia hammondi was also determined.MethodsEurasian red squirrels that were found dead in the wild or that had died in wildlife rescue centres in the Netherlands over a period of seven years (2014-2020) were examined. Quantitative real-time polymerase chain reaction was conducted to analyse tissue samples for the presence of T. gondii and H. hammondi DNA. Toxoplasma gondii-positive samples were subjected to microsatellite typing and cluster analysis. A mixed logistic regression was used to identify climatic and other environmental predictors of T. gondii infection in the squirrels.ResultsA total of 178 squirrels were examined (49/178 T. gondii positive, 5/178 H. hammondi positive). Inflammation of multiple organs was the cause of death in 29 squirrels, of which 24 were also T. gondii polymerase chain reaction positive. Toxoplasma gondii infection was positively associated with pneumonia and hepatitis. Microsatellite typing revealed only T. gondii type II alleles. Toxoplasma gondii infection rates showed a positive correlation with the number of days of heavy rainfall in the previous 12 months. Conversely, they showed a negative association with the number of hot days within the 2-week period preceding the sampling date, as well as with the percentage of deciduous forest cover at the sampling site.ConclusionsToxoplasma gondii infection in the squirrels appeared to pose a significant risk of acute mortality. The T. gondii genotype detected in this study is commonly found across Europe. The reasons for the unusually high infection rates and severe symptoms of these squirrels from the Netherlands remain unclear. The prevalence of T. gondii in the deceased squirrels was linked to specific environmental factors. However, whether the increase in the number of dead squirrels indicated a higher environmental contamination with T. gondii oocysts has yet to be established.

Project description:Conservation translocations, including reintroductions, are practices that are vital to restoring biodiversity and ecosystem function within conservation schemes globally. Sadly, population translocations have had a poor success rate historically. At a time where biodiversity is constantly decreasing, improving translocation success is vital for future conservation schemes. Often, to improve success, the selection of individuals is based on genetic characteristics and behaviours linked directly to survival. Further development to improve selection is proposed within this paper using animal personality. The study took place opportunistically to test how personality, in particular an animal's boldness/timidness, may influence a population restoration of red squirrels into the Ogwen Valley, North Wales. Despite frequent translocations, data on how boldness and timidness may affect the establishment of this species are low. Testing was performed on key survival behaviours and boldness/timidness pre-release. This was performed via video data collection and identification of key behaviours that could be used to identify boldness or behaviours that could be linked to reduced fitness once released. Encounters at different distance intervals were monitored post-release via camera trapping to identify if boldness/timidness may change the furthest encounter distance of focal animals away from their release site. Relationships between the period for an individual to reappear post-threat was significantly linked to boldness, with other behavioural results and the encounter distance also showing trends of a potential relationship. Our results indicate that bolder individuals have a higher chance of expressing behavioural traits that will increase exposure to risks and, therefore, reduce the likelihood of successfully establishing populations. However, the small sample size of this study means that further research is needed. We suggest that during early stages of conservation translocation programmes, personality testing for boldness should become common practice, and we recommend selecting timid individuals for an initial release to improve population establishment, with bolder individuals utilised later to expand population distribution.

Project description:Effective methods for monitoring animal populations are crucial for species conservation and habitat management. Motion-activated cameras provide an affordable method for passively surveying animal presence across the landscape but have mainly been used for studying large-bodied mammals. This paper explores the relative abundance and habitat preferences of red squirrels (Sciurus vulgaris) in coniferous forests using cameras and live trapping. The study was conducted in two forests (Newborough and Pentraeth) on Anglesey, North Wales, with a total of 50 sampling locations across four habitat categories. Detailed woodland structure and composition data were gathered around each sampling location. We found a strong positive correlation between the number of individual red squirrels live trapped over 10 days with the number of camera images of squirrels recorded during a previous 5-day period. The time interval between camera deployment and the first recorded image of a red squirrel showed a significant negative correlation with the number of individuals live trapped. Red squirrel relative abundance was negatively related to forest canopy openness, while the presence of Scots pine and increased tree species diversity were positively associated with the relative abundance of squirrels. There was also a strong site difference with lower relative abundance at Newborough compared with Pentraeth, which likely reflects the heavy thinning of mature forest at Newborough reducing tree crown connectivity. The results show that remotely activated cameras are an effective method for monitoring red squirrel populations across varying animal densities. The cameras also provided crucial information on red squirrel habitat preferences that can aid in woodland management and conservation efforts. Cameras have great potential to collect data on the population status of other small mammals, but it is essential that these methods are validated on a species-by-species basis.

Dataset Information

Conservation of genetic uniqueness in remaining populations of red squirrels (Sciurus vulgaris L.) in the South of England.

Publications

Conservation of genetic uniqueness in remaining populations of red squirrels (<i>Sciurus vulgaris</i> L.) in the South of England.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets