Significant differences in the caecal bacterial microbiota of red and grey squirrels in Britain.

Introduction. Red squirrel populations have declined in the UK since the introduction of the grey squirrel, due to resource competition and grey squirrels carrying a squirrelpox virus that is fatal to red squirrels.Hypothesis/Gap Statement. It is not known if the gut microbiota of the two species is similar and if this could impact the survival of red squirrels.Aim. The aim of this study was to profile the caecal microbiota of red and grey squirrels obtained opportunistically from a conservation programme in North Wales.Methodology. Bacterial DNA was extracted from ten red and ten grey squirrels and sent for 16S rRNA sequencing. Three samples from red squirrels returned less than 5000 reads, and so were not carried forward for further analyses.Results. Samples taken from the caeca of red squirrels had significantly lower bacterial diversity and a higher percentage of Bacilli bacteria when compared to samples from grey squirrels. When the abundance of bacterial groups across all levels of phylogenetic classifications was compared between the two groups of squirrels, grey squirrels had a higher abundance of bacteria belonging to the families S24-7, RF39 and Rikenellaceae. Escherichia coli with resistance to amoxicillin/clavulanic acid was identified in all samples. Cefotaxime resistance was identified in two samples from grey squirrels along with sulfamethoxazole/trimethoprim in one of these samples.Conclusion. Clear differences between the caecal microbiota of the two species of squirrel were identified, which could potentially impact their overall health and ability to compete for resources.

Capturing red squirrels (Sciurus vulgaris) on camera: A cost-effective approach for monitoring relative abundance and habitat preference.

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.

Opportunistic viral surveillance confirms the ongoing disease threat grey squirrels pose to sympatric red squirrel populations in the UK.

BACKGROUND: Red Squirrels United was a UK landscape-scale grey squirrel management programme undertaken between 2016 and 2020. METHODS: A total of 11034 grey squirrels were removed by culling, with 1506 necropsied and 1405 suitable for adenovirus (AdV) or squirrelpox virus (SQPV) quantitative PCR (qPCR) analysis. Spleen, lip or hair were extracted, and DNA was isolated, with samples tested in duplicate by qPCR. RESULTS: Of 1378 tissue samples, 43% were positive for AdV and 10% for SQPV. Of 1031 hair samples, 11% were positive for AdV and 10% for SQPV. Overall, 762 of 1405 (54%) animals were positive for one or both viruses. LIMITATIONS: Ad hoc sampling was undertaken from limited geographical areas but provided the only dataset from that period, instead of extrapolating from historical data. CONCLUSIONS: The grey squirrel is an asymptomatic reservoir host for AdV and SQPV. Interspecific infection transmission potential is demonstrated. Grey squirrel management by culling is essential for mainland red squirrel viability until other suitable management tools are available.

An Opportunistic Assessment of the Impact of Squirrelpox Disease Outbreaks upon a Red Squirrel Population Sympatric with Grey Squirrels in Wales.

Native red squirrels (Sciurus vulgaris) persisted in the coastal mainland woodlands of northern Gwynedd whilst sympatric with an invasive grey squirrel (Sciurus carolinensis) population suppressed by culling. Squirrelpox disease in the red squirrel population was recorded in 2017 and 2020/21. An autumn 2020 outbreak was associated with only 17.4% of animals caught and marked in the preceding June known to be present in March 2021. Despite an opportunistic data collection lacking the rigour of empirical experimental design, we observed low local survival rates similar to previously published accounts reported during major squirrelpox outbreaks. The use of a conservation dog to detect red squirrel carcasses resulted in positive detection and confirmation of a temporal and spatial expansion of one disease outbreak. The study is the first in Wales to use conservation dogs and the findings reinforce the vital strategic importance of geographical isolation reducing sympatry of red with grey squirrels in European regions where the introduced congener is a source of the squirrelpox infection.

Do Differing Levels of Boldness Influence the Success of Translocation? A Pilot Study on Red Squirrels (Sciurus vulgaris).

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.

Deconstructing compassionate conservation.

Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.

Deconstrucción de la Conservación Compasiva Resumen La conservación compasiva se enfoca en cuatro principios: no causar daño; los individuos importan; la integración de los animales individualmente; y la coexistencia pacífica entre los humanos u los animales. Recientemente, la conservación compasiva ha sido promovida como una alternativa a la filosofía convencional de la conservación. Creemos que los ejemplos presentados por los conservacionistas compasivos han sido elegidos arbitraria o deliberadamente por estar enfocados en los mamíferos; por ser inherentes y no compasivos; y por ofrecer soluciones de conservación poco efectivas. La conservación compasiva se enfoca arbitrariamente en las especies carismáticas, principalmente los grandes depredadores y los megaherbívoros. La filosofía no es compasiva cuando deja que los depredadores invasores dentro del ambiente causen daño a un vasto número de individuos nativos o usa el miedo al daño por superdepredadores para aterrorizar a los mesodepredadores. El entorpecimiento del control de especies exóticas (megafauna, depredadores) in situ no mejorará las condiciones de conservación de la mayoría de la biodiversidad, incluso si los conservacionistas compasivos no dañan a los individuos exóticos. Las posiciones que toman los llamados conservacionistas compasivos sobre especies particulares y sobre las acciones de conservación podrían extenderse para entorpecer otros tipos de conservación, incluyendo las reubicaciones, el encercado para la conservación y el control de la fertilidad. El bienestar animal es increíblemente importante para la conservación e irónicamente, la conservación compasiva no ofrece los mejores resultados de bienestar para los animales y comúnmente es poco efectiva en el logro de los objetivos de conservación. Como consecuencia, la conservación compasiva puede poner en peligro el apoyo público y del gobierno que tiene la conservación debido al entendimiento poco limitado que tiene el público general sobre los problemas de conservación.

British Red Squirrels Remain the Only Known Wild Rodent Host for Leprosy Bacilli.

Eurasian red squirrels (Sciurus vulgaris) in the British Isles are the most recently discovered animal reservoir for the leprosy bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. Nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (Siberian chipmunk [Tamias sibiricus], and Thirteen-lined ground squirrel [Ictidomys tridecemlineatus]) having been reported to be susceptible to experimental infection with M. leprae. Rats, a food-source in some countries where human leprosy occurs, have been suggested as potential reservoirs for leprosy bacilli, but no evidence supporting this hypothesis is currently available. We screened 301 squirrel samples covering four species [96 Eurasian red squirrels, 67 Eastern gray squirrels (Sciurus carolinensis), 35 Siberian chipmunks, and 103 Pallas's squirrels (Callosciurus erythraeus)] from Europe and 72 Mexican white-throated woodrats (Neotoma albigula) for the presence of M. leprae and M. lepromatosis using validated PCR protocols. No DNA from leprosy bacilli was detected in any of the samples tested. Given our sample-size, the pathogen should have been detected if the prevalence and/or bacillary load in the populations investigated were similar to those found for British red squirrels.

The large-scale removal of mammalian invasive alien species in Northern Europe.

Numerous examples exist of successful mammalian invasive alien species (IAS) eradications from small islands (<10 km2 ), but few from more extensive areas. We review 15 large-scale removals (mean area 2627 km2 ) from Northern Europe since 1900, including edible dormouse, muskrat, coypu, Himalayan porcupine, Pallas' and grey squirrels and American mink, each primarily based on daily checking of static traps. Objectives included true eradication or complete removal to a buffer zone, as distinct from other programmes that involved local control to limit damage or spread. Twelve eradication/removal programmes (80%) were successful. Cost increased with and was best predicted by area, while the cost per unit area decreased; the number of individual animals removed did not add significantly to the model. Doubling the area controlled reduced cost per unit area by 10%, but there was no evidence that cost effectiveness had increased through time. Compared with small islands, larger-scale programmes followed similar patterns of effort in relation to area. However, they brought challenges when defining boundaries and consequent uncertainties around costs, the definition of their objectives, confirmation of success and different considerations for managing recolonisation. Novel technologies or increased use of volunteers may reduce costs. Rapid response to new incursions is recommended as best practice rather than large-scale control to reduce the environmental, financial and welfare costs. © 2016 Crown copyright. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.