Is it Advisable to Rehabilitate and Release Owls with Monocular Vision?

Defective vision is frequent in owls presented to rehabilitation centers. While there is a common consensus that completely blind owls should not be released, there is less certainty when considering owls with monocular vision. To address this issue, surveys of rehabilitation centers and veterinarians were conducted regarding their opinion and experience on the feasibility and ethics of rehabilitating and releasing owls with only one functional eye. Results show conflicting opinions between rehabilitation centers and also veterinarians, with a lack of agreement on what would be best in terms of welfare. This research also compared flight and landing behaviour of four barn owls, of which two had lens opacities to differing degrees and one had only one eye. No significant differences were found between the one-eyed barn owl and the three birds with two eyes in any of the aspects analyzed, namely flight trajectory and time and landing ability on a perch or a handler’s glove. Finally, from a literature review and reports from the centers surveyed, successful cases of rehabilitation and release of owls with monocular vision were documented. The findings of our research suggest that new UK guidelines which describe the prerequisites for release of owls with monocular vision should be develope

The risk from SARS-CoV-2 to bat species in england and mitigation options for conservation field workers

The newly evolved coronavirus, SARS-CoV-2, which has precipitated a global COVID-19 pandemic among the human population, has been shown to be associated with disease in captive wild animals. Bats (Chiroptera) have been shown to be susceptible to experimental infection and therefore may be at risk from disease when in contact with infected people. Numerous conservation fieldwork activities are undertaken across the United Kingdom bringing potentially infected people into close proximity with bats. In this study, we analysed the risks of disease from SARS-CoV-2 to free-living bat species in England through fieldworkers undertaking conservation activities and ecological survey work, using a qualitative, transparent method devised for assessing threats of disease to free-living wild animals. The probability of exposure of bats to SARS-CoV-2 through fieldwork activities was estimated to range from negligible to high, depending on the proximity between bats and people during the activity. The likelihood of infection after exposure was estimated to be high and the probability of dissemination of the virus through bat populations medium. The likelihood of clinical disease occurring in infected bats was low, and therefore, the ecological, economic and environmental consequences were predicted to be low. The overall risk estimation was low, and therefore, mitigation measures are advisable. There is uncertainty in the pathogenicity of SARS-CoV-2 in bats and therefore in the risk estimation. Disease risk management measures are suggested, including the use of personal protective equipment, good hand hygiene and following the existing government advice. The disease risk analysis should be updated as information on the epidemiology of SARS-CoV-2 and related viruses in bats improves. The re-analysis may be informed by health surveillance of free-living bats

A Comparison of Disease Risk Analysis Tools for Conservation Translocations

Conservation translocations are increasingly used to manage threatened species and restore ecosystems. Translocations increase the risk of disease outbreaks in the translocated and recipient populations. Qualitative disease risk analyses have been used as a means of assessing the magnitude of any effect of disease and the probability of the disease occurring associated with a translocation. Currently multiple alternative qualitative disease risk analysis packages are available to practitioners. Here we compare the ease of use, expertise required, transparency, and results from, three different qualitative disease risk analyses using a translocation of the endangered New Zealand passerine, the hihi (Notiomystis cincta), as a model. We show that the three methods use fundamentally different approaches to define hazards. Different methods are used to produce estimations of the risk from disease, and the estimations are different for the same hazards. Transparency of the process varies between methods from no referencing, or explanations of evidence to justify decisions, through to full documentation of resources, decisions and assumptions made. Evidence to support decisions on estimation of risk from disease is important, to enable knowledge acquired in the future, for example from translocation outcome, to be used to improve the risk estimation for future translocations. Information documenting each disease risk analysis differs along with variation in emphasis of the questions asked within each package. The expertise required to commence a disease risk analysis varies and an action flow chart tailored for the non-wildlife health specialist are included in one method but completion of the disease risk analysis requires wildlife health specialists with epidemiological and pathological knowledge in all three methods. We show that disease risk analysis package choice may play a greater role in the overall risk estimation of the effect of disease on animal populations involved in a translocation than might previously have been realised

Molecular identification of Sarcocystis wobeseri-like parasites in a new intermediate host species, the white-tailed sea eagle (Haliaeetus albicilla)

A reintroduced white-tailed sea eagle (Haliaeetus albicilla) in moderate body condition was found dead and submitted for post-mortem examination. There were no signs of disease on gross pathological examination. Histopathological examination however revealed the presence of encysted protozoan parasites in pectoral and cardiac muscle sections. Polymerase chain reaction amplification of extracted genomic DNA and sequencing of four regions: the 18S rDNA, 28S rDNA, internal transcribed spacer (ITS) 1, and RNA polymerase B (rpoB) loci, confirmed the presence of a Sarcocystis species in pectoral and cardiac muscle which appeared phylogenetically similar to Sarcocystis wobeseri. This is the first report of S. wobeseri-like infection in a white-tailed sea eagle revealing a new intermediate host species for this parasite

Protecting Free-Living Dormice: Molecular Identification of Cestode Parasites in Captive Dormice (Muscardinus avellanarius) Destined for Reintroduction

The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding. Using PCR sequencing of a range of genes, we tested whether the same species of tapeworm(s) were present in captive and free-living dormice. Whilst only Rodentolepis straminea were identified in free-living dormice, cestode ova found in a captive individual produced a molecular match closely related to Hymenolepis microstoma and a previously unrecorded Rodentolepis species. To prevent putting at risk the free-living population, we recommended the continued treatment of dormice showing tapeworm infection before release. Our work demonstrates how molecular techniques can be used to inform reintroduction programmes, reduce risk from disease and increase chances of reintroduction success

Using Qualitative Disease Risk Analysis for Herpetofauna Conservation Translocations Transgressing Ecological and Geographical Barriers

Through the exploration of disease risk analysis methods employed for four different UK herpetofauna translocations, we illustrate how disease hazards can be identified, and how the risk of disease can be analysed. Where ecological or geographical barriers between source and destination sites exist, parasite populations are likely to differ in identity or strain between the two sites, elevating the risk from disease and increasing the number and category of hazards requiring analysis. Simplification of the translocation pathway through the avoidance of these barriers reduces the risk from disease. The disease risk analysis tool is intended to aid conservation practitioners in decision making relating to disease hazards prior to implementation of a translocation

Scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM-EDX) confirms shooting of a hen harrier (Circus cyaneus)

The hen harrier (Circus cyaneus) remains severely restricted as a breeding species in England despite sufficient habitat for over 300 breeding pairs. Human persecution is the main limiting factor and in the UK, there have been 45 confirmed incidents of shooting of hen harriers since records began (Royal Society for the Protection of Birds unpublished data). The authors report the pathological examination of a hen harrier, the detection of suspected ballistic fragments by radiograph and explain how scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM-EDX) was used to confirm (i) the composition of one ballistic remnant and (ii) that the remnant had been projected into and had damaged the bone. The authors report the use of post-analysis software to discriminate apparent anomalies produced by the proprietary SEM-EDX software package and discuss broader uses of SEM-EDX for wildlife crime investigation

Squirrelpox virus: assessing prevalence, transmission and environmental degradation

Red squirrels (Sciurus vulgaris) declined in Great Britain and Ireland during the last century, due to habitat loss and the introduction of grey squirrels (Sciurus carolinensis), which competitively exclude the red squirrel and act as a reservoir for squirrelpox virus (SQPV). The disease is generally fatal to red squirrels and their ecological replacement by grey squirrels is up to 25 times faster where the virus is present. We aimed to determine: (1) the seropositivity and prevalence of SQPV DNA in the invasive and native species at a regional scale; (2) possible SQPV transmission routes; and, (3) virus degradation rates under differing environmental conditions. Grey (n = 208) and red (n = 40) squirrel blood and tissues were sampled. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR) techniques established seropositivity and viral DNA presence, respectively. Overall 8% of squirrels sampled (both species combined) had evidence of SQPV DNA in their tissues and 22% were in possession of antibodies. SQPV prevalence in sampled red squirrels was 2.5%. Viral loads were typically low in grey squirrels by comparison to red squirrels. There was a trend for a greater number of positive samples in spring and summer than in winter. Possible transmission routes were identified through the presence of viral DNA in faeces (red squirrels only), urine and ectoparasites (both species). Virus degradation analyses suggested that, after 30 days of exposure to six combinations of environments, there were more intact virus particles in scabs kept in warm (25°C) and dry conditions than in cooler (5 and 15°C) or wet conditions. We conclude that SQPV is present at low prevalence in invasive grey squirrel populations with a lower prevalence in native red squirrels. Virus transmission could occur through urine especially during warm dry summer conditions but, more notably, via ectoparasites, which are shared by both species