The Recovery of the Polecat Mustela putorius in Great Britain

Many carnivore species are experiencing declines due to anthropogenic factors such as direct killing, habitat loss, secondary exposure to chemical control agents, and depletion of prey resources. Due to their top-down effects on the structure and function of ecosystems, carnivores are, however, increasingly the focus of efforts towards ecological restoration. To enable such restoration to take place, wildlife managers need to understand both the ecological processes and the social-ecological factors that may affect carnivore recovery and establishment. In this thesis, I use the European polecat Mustela putorius, which is currently recolonising Great Britain following near extirpation in the nineteenth century, as a case study through which to explore the processes of carnivore recovery. I investigate social and ecological risks to the polecat’s continuing range and population expansion, which may also be pertinent to the wider challenges of carnivore conservation. In my introduction, I outline the importance of carnivores to ecosystem function and review the wide-ranging and cascading effects their reinstatement can have. I provide an overview of human-carnivore interactions and the anthropogenic processes that directly or indirectly lead to carnivore declines. I give a historical context to human-carnivore relations in Great Britain, introduce polecats, their biology and changing status and provide an overview of my research objectives and thesis structure. I then carry out a detailed literature review of the changing status of the eight terrestrial mammalian carnivores native to Great Britain. I summarise the anthropogenic processes that have influenced their status. I find that polecats have recolonised Great Britain less quickly than otters Lutra lutra but more quickly than pine martens Martes martes. Badgers Meles meles have increased in abundance. Foxes Vulpes vulpes are experiencing a decline and wildcat are imperilled by hybridisation with domestic cats. Stoats Mustela erminea and weasels Mustela nivalis are data deficient, but evidence suggests that stoats may be increasing in number relative to weasels. Next, I explore polecat resource use during a period of ecological change by analysing the stable isotopes of carbon and nitrogen from a museum collection of polecat whiskers. I find that variation in isotope ratios and isotopic niches indicate differences in resource use between polecats collected from the leading edge of the range compared to the established parts of the range and that this effect was greatest in the 1960s when rabbits Oryctolagus cuniculus—an important prey for polecats—were in low abundance. I also find that female polecats show greater variation in resource use than males, indicating that they may have different needs as part of conservation efforts. Next, I carry out a study of polecat diets to assess responses to fluctuating abundance of rabbits. I analyse the stomach contents from polecat carcasses collected between 2013 and 2016. I compare my results with those from earlier polecat dietary studies and find that the proportion of lagomorphs increased in polecat diet between the 1960s and 1990s. Although rabbit populations have been declining since the 1990s, I find no difference in the proportion of lagomorphs in polecat diet between the 1990s and 2010s. Secondary exposure to second generation anticoagulant rodenticides is a contemporary risk to polecat recovery that is also related to their diet, as polecats are likely exposed to rodenticides by eating contaminated rodents. In Chapter 5, I analyse the livers from polecat carcasses collected between 2013 and 2016 to measure current levels of secondary exposure and explore factors that may affect exposure. I find that the frequency of exposure to rodenticides was 79% in polecats and that this represents a 1.7 fold increase in exposure frequency over 25 years. I find that the probability of exposure increases with age and with increasing values of ẟ15N, suggesting that resource use influences polecat exposure to rodenticides. I then explore the principles underpinning modern gamekeeping practices, by carrying out interviews with gamekeepers to find out what they do and why. In this qualitative study, I analyse gamekeepers’ conception of The Balance, which is an overarching narrative that they have adopted to explain their approach to wildlife management. Although The Balance includes echoes of the heuristic of the ‘balance-of-nature’, it is most often employed in the context of maximising shootable game surpluses while providing opportunities to other wildlife that do not conflict with this objective. I find that keeping The Balance requires a ritualised, highly interventionist approach to producing game that presents both risks and rewards to predators. The multiplicity of The Balance—in which gamekeepers are stewards of both game and the countryside—creates an ambiguity that, when associated with the regular culling of predators and negative perceptions of sport shooting, may cause misunderstandings between gamekeepers and other publics. In conclusion, I find that polecats have been able to recolonise most of southern Britain despite the risks of fluctuating rabbit populations, increasing exposure to rodenticides and predator controls. Polecat recovery has occurred with minimal direct conservation effort. It has also taken a long time: one hundred years after their population nadir, polecats are yet to fully recolonise their former range. More broadly, a low-intervention approach is unlikely to succeed, or be desirable, for all carnivores. In particular, those that are slower to mature, have lower reproductive rates, more specialised resource requirements and greater impact on anthropogenic practices, or where the potential ecological benefits that may be derived from a species’ restoration necessitate an expedited recovery.People's Trust for Endangered SpeciesVincent Wildlife TrustVincent Wildlife TrustVincent Wildlife TrustVincent Wildlife Trus

Incapacity Benefit Reforms Pilot: Findings from a longitudinal panel of clients

The Incapacity Benefit reforms were introduced in October 2003 and aim to increase the number of incapacity benefit recipients who move towards and into paid work. The package of measures that comprise the reforms is being Piloted in seven areas of England, Scotland and Wales. This report is based on research conducted by the Social Policy Research Unit, the National Centre for Social Research and the Policy Studies Institute in 2004/05 and presents findings from the first cohort of a longitudinal qualitative study of the views and experiences of incapacity benefit recipients who have taken part in the Pilots

Design of a large scale experiment for measuring effects of fishing on the Great Barrier Reef

There is considerable concern about the effects of fishing on the GBR. Two types of fishing may have substantial effects over large areas: (1) "line" fishing (recreational and commercial) for larger species such as coral trout, and (2) commercial "trawl" fishing for prawns and scallops in inter-reef areas and in the GBR lagoon inshore of the midshelf reef complex. Besides directly affecting the abundance of target species, line fishing may have a variety of indirect effects by altering the trophic structure (predator-prey interactions, competition) of reef communities. Trawling may affect benthic communities used by reef species for functions such as feeding, dispersal, and juvenile rearing. There may be important "interaction effects" between line and trawl fishing, particularly if trawling affects dispersal of fish among reefs and hence the immigration component of recruitment to reef populations subject to line fishing (ie, line fishing effects may be larger in areas where trawling is present, due to reduced replenishment of heavily fished reef populations by dispersal from areas where less fishing occurs)

AN INVESTIGATION OF THE ACTIVATION OF THE SUBDIVISIONS OF GLUTEUS MEDIUS DURING ISOMETRIC HIP CONTRACTIONS

Gluteus medius is involved in movement and stability of the hip and gluteus medius dysfunction is commonly implicated in many lower limb pathologies (Fredericson et al 2000). It is proposed that functional subdivisions exist within the gluteus medius muscle (Conneely and O’Sullivan 2008). There is however a lack of empirical evidence examining the role of the subdivisions of gluteus medius. This study compared the muscle activation of these subdivisions (anterior, middle and posterior) during isometric contractions of hip abduction, internal and external rotation in normal subjects

Some explorations of the life history ratios to describe length composition, spawning-per-recruit, and the spawning potential ratio

Evaluating the status of data-poor fish stocks is often limited by incomplete knowledge of the basic life history parameters: the natural mortality rate (M), the von Bertalanffy growth parameters (L∞ and k), and the length at maturity (Lm). A common approach to estimate these individual parameters has been to use the Beverton–Holt life history invariants, the ratios M/k and Lm/L∞, especially for estimating M. In this study, we assumed no knowledge of the individual parameters, and explored how the information on life history strategy contained in these ratios can be applied to assessing data-poor stocks. We developed analytical models to develop a relationship between M/k and the von Bertalanffy growth curve, and demonstrate the link between the life history ratios and yield- and spawning-per-recruit. We further developed the previously recognized relationship between M/k and yield- and spawning-per-recruit by using information on Lm/L∞, knife-edge selectivity (Lc/L∞), and the ratio of fishing to natural mortality (F/M), to demonstrate the link between an exploited stock's expected length composition, and its spawning potential ratio (SPR), an internationally recognized measurement of stock status. Variation in length-at-age and logistic selectivity patterns were incorporated in the model to demonstrate how SPR can be calculated from the observed size composition of the catch; an advance which has potential as a cost-effective method for assessing data-poor stocks. A companion paper investigates the effects of deviations in the main assumptions of the model on the application of the analytical models developed in this study as a cost-effective method for stock assessment [Hordyk, A. R., Ono, K., Valencia, S., Loneragan, N. R., and Prince, J. D. this issue. A novel length based empirical estimation method of spawning potential ratio (SPR), and tests of its performance, for small-scale, data-poor fisheries.

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