Systematic assessment of the impact of adenovirus infection on a captive reintroduction project for red squirrels (Sciurus vulgaris).

PCR was used to amplify adenoviral DNA, and transmission electron microscopy (TEM) to detect adenovirus particles in tissue and intestinal content samples from red squirrels (Sciurus vulgaris) associated with a reintroduction study on Anglesey (North Wales), from other populations on the island and from stock held at the Welsh Mountain Zoo, 38 km to the east. Samples were collected during the routine surveillance postmortem examinations of all 60 red squirrels with carcases retrieved in a suitable condition between 2004 and 2010, including 29 captive and 31 free-living animals. Following significant clusters of mortality in captive red squirrels, adenovirus was identified retrospectively in faecal material from 12 of 13 (92 per cent) examined carcases from squirrels captive on Anglesey, and 14 of 16 (88 per cent) from the Welsh Mountain Zoo. Virus was identified in 13 of 31 (42 per cent) free-living wild animals, with evidence of both subclinical and clinically significant enteric adenoviral infections in wild squirrels. Without ancillary PCR and TEM testing, the extent of adenovirus infection in such populations would have been underestimated. Screening protocols that include examinations for adenovirus should, therefore, be part of the routine biosecurity measures protecting reintroduction or captive breeding programmes for red squirrels.

Identifying governance strategies that effectively support ecosystem services, resource sustainability, and biodiversity.

Conservation scientists, national governments, and international conservation groups seek to devise, and implement, governance strategies that mitigate human impact on the environment. However, few studies to date have systematically investigated the performance of different systems of governance in achieving successful conservation outcomes. Here, we use a newly-developed analytic framework to conduct analyses of a suite of case studies, linking different governance strategies to standardized scores for delivering ecosystem services, achieving sustainable use of natural resources, and conserving biodiversity, at both local and international levels. Our results: (i) confirm the benefits of adaptive management; and (ii) reveal strong associations for the role of leadership. Our work provides a critical step toward implementing empirically justified governance strategies that are capable of improving the management of human-altered environments, with benefits for both biodiversity and people.

On the replacement of the red squirrel in Britain: a phytotoxic explanation.

Diffusion modelling has shown that conservative demographic traits combined with feeding competition could explain red squirrel replacement by grey squirrels. We used field data from seven separate red and grey squirrel populations, in oak-hazel woods and Scots pines, to reject the hypothesis that red squirrel density and breeding is intrinsically poorer than that of grey squirrels. In oak-hazel woods, grey squirrel foraging, density and productivity were related to oak and acorn abundance. In contrast, red squirrels foraged where hazels were abundant; their relatively low density and breeding success were related to the abundance of hazel nuts. Red squirrels failed to exploit good acorn crops, although acorns were more abundant than hazels, but in Scots pines had densities and breeding success as high as grey squirrels in deciduous woods. Captive grey squirrels thrived on a diet of acorns, but red squirrels had a comparative digestive efficiency of only 59%, apparently because they were much less able than grey squirrels to neutralize acorn polyphenols. A model with simple competition for the autumn hazel crop, which was eaten by grey squirrels before the acorn crop, shows that red squirrels are unlikely to persist with grey squirrels in woods with more than 14% oak canopy. With oaks in most British deciduous woods giving grey squirrels a food refuge which red squirrels fail to exploit, replacement of red squirrels can be explained by feeding competition alone, exacerbated by the post-war decline in coppiced hazel.

A survey of the bacterial flora of the feet of free-living goshawks (Accipiter gentilis).

The feet of goshawks (Accipiter gentilis) were swabbed. Bacteriological examination demonstrated that the feet were colonised by organisms from many genera some of which were recognised avian pathogens.