Exclusions for resolving urban badger damage problems: Outcomes and consequences

Increasing urbanisation and growth of many wild animal populations can result in a greater frequency of human-wildlife conflicts. However, traditional lethal methods of wildlife control are becoming less favoured than non-lethal approaches, particularly when problems involve charismatic species in urban areas. Eurasian badgers (Meles meles) excavate subterranean burrow systems (setts), which can become large and complex. Larger setts within which breeding takes place and that are in constant use are known as main setts. Smaller, less frequently occupied setts may also exist within the social group's range. When setts are excavated in urban environments they can undermine built structures and can limit or prevent safe use of the area by people. The most common approach to resolving these problems in the UK is to exclude badgers from the problem sett, but exclusions suffer a variable success rate. We studied 32 lawful cases of badger exclusions using one-way gates throughout England to evaluate conditions under which attempts to exclude badgers from their setts in urban environments were successful. We aimed to identify ways of modifying practices to improve the chances of success. Twenty of the 32 exclusion attempts were successful, but success was significantly less likely if a main sett was to be excluded in comparison with another type of sett and if vegetation was not completely removed from the sett surface prior to exclusion attempts. We recommend that during exclusions all vegetation is removed from the site, regardless of what type of sett is involved, and that successful exclusion of badgers from a main sett might require substantially more effort than other types of sett

Xirp Proteins Mark Injured Skeletal Muscle in Zebrafish

Myocellular regeneration in vertebrates involves the proliferation of activated progenitor or dedifferentiated myogenic cells that have the potential to replenish lost tissue. In comparison little is known about cellular repair mechanisms within myocellular tissue in response to small injuries caused by biomechanical or cellular stress. Using a microarray analysis for genes upregulated upon myocellular injury, we identified zebrafish Xin-actin-binding repeat-containing protein1 (Xirp1) as a marker for wounded skeletal muscle cells. By combining laser-induced micro-injury with proliferation analyses, we found that Xirp1 and Xirp2a localize to nascent myofibrils within wounded skeletal muscle cells and that the repair of injuries does not involve cell proliferation or Pax7+ cells. Through the use of Xirp1 and Xirp2a as markers, myocellular injury can now be detected, even though functional studies indicate that these proteins are not essential in this process. Previous work in chicken has implicated Xirps in cardiac looping morphogenesis. However, we found that zebrafish cardiac morphogenesis is normal in the absence of Xirp expression, and animals deficient for cardiac Xirp expression are adult viable. Although the functional involvement of Xirps in developmental and repair processes currently remains enigmatic, our findings demonstrate that skeletal muscle harbours a rapid, cell-proliferation-independent response to injury which has now become accessible to detailed molecular and cellular characterizations

Factors affecting bait uptake by the grey squirrel (Sciurus carolinensis) and the future delivery of oral contraceptives

Context: Invasive species negatively affect natural communities and human activities. The grey squirrel is an invasive species in the UK, causing damage to forestry and the decline of the native red squirrel. Oral contraceptives have the potential to reduce numbers of grey squirrels; however, to be effective a sufficient proportion of a population must consume a bait containing contraceptives. Aims: The objective of this study was to estimate the efficacy of delivering baits via feeders to grey squirrels and to determine the factors most important to bait uptake. Methods: Bait uptake was measured using the bait marker Rhodamine B mixed with 100% hazelnut butter and delivered to grey squirrels via purpose-designed feeders. Different concentrations of Rhodamine B were first trialled on captive grey squirrels for their palatability and detectability in the hair. Bait-uptake field trials were then conducted in 10 UK woodlands by using the preferred concentration. Key results: In captive trials, it was found that a concentration of 0.18% Rhodamine B mixed in hazelnut butter was palatable to grey squirrels and that individuals needed to consume only small amounts (<5 g) for it to be detected in the flank hair by using an ultraviolet microscope. It was possible to deliver bait to the majority of grey squirrels in 6 of 10 woods within 4 days. Season, feeder density and squirrel density were important factors affecting bait uptake, with more squirrels consuming bait in summer than in winter and from three feeders per hectare rather than from one per hectare. Conclusions: This study demonstrated that baits delivered via feeders can target the majority of grey squirrels in woodland environments. Implications: Oral contraceptives could offer a cost-effective tool to reduce numbers of grey squirrels across the UK landscape and mitigate the negative impacts they have on native wildlife and tree health

A camera trap method for estimating target densities of grey squirrels to inform wildlife management applications

Effective wildlife population management requires an understanding of the abundance of the target species. In the UK, the increase in numbers and range of the non-native invasive grey squirrel Sciurus carolinensis poses a substantial threat to the existence of the native red squirrel S. vulgaris, to tree health, and to the forestry industry. Reducing the number of grey squirrels, is crucial to mitigate their impacts. Camera traps are increasingly used to estimate animal abundance, and methods have been developed that do not require the identification of individual animals. Most of these methods have been focussed on medium to large mammal species with large range sizes and may be unsuitable for measuring local abundances of smaller mammals that have variable detection rates and hard to measure movement behaviour. The aim of this study was to develop a practical and cost-effective method, based on a camera trap index, that could be used by practitioners to estimate target densities of grey squirrels in woodlands to provide guidance on the numbers of traps or contraceptive feeders required for local grey squirrel control. Camera traps were deployed in ten independent woods of between 6 and 28 ha in size. An index, calculated from the number of grey squirrel photographs recorded per camera per day had a strong linear relationship (R2 = 0.90) with the densities of squirrels removed in trap and dispatch operations. From different time filters tested, a 5 minute filter was applied, where photographs of squirrels recorded on the same camera within 5 minutes of a previous photograph were not counted. There were no significant differences between the number of squirrel photographs per camera recorded by three different models of camera, increasing the method's practical application. This study demonstrated that a camera index could be used to inform the number of feeders or traps required for grey squirrel management through culling or contraception. Results could be obtained within six days without requiring expensive equipment or a high level of technical input. This method can easily be adapted to other rodent or small mammal species, making it widely applicable to other wildlife management interventions

A PIT-tag based method for measuring individual bait uptake in small mammals

1. Rodents and other small mammals cause an increasing number of negative economic and environmental impacts worldwide. In the UK, the non-native grey squirrel has a significant impact on the forestry industry and has caused the decline of the native red squirrel. 2. Baits are used to deliver biocides and contraceptives to reduce overabundant wildlife populations and as vehicles for vaccines to control disease outbreaks. Bait-delivered contraceptives are also being developed to manage grey squirrel populations in the UK. The effectiveness of bait-delivered drugs on wildlife populations depends on the amount of bait consumed by individuals over time; therefore, it is important to understand individual level bait uptake in order to optimise delivery methods. 3. Passive Integrated Transponder (PIT) tags are increasingly used to mark and monitor animal behaviour as they are cost-effective, have minimal negative welfare impacts and have a lower tag loss rate than external tags, particularly in small animals. 4. The aim of this study was to design and test a novel bait hopper equipped with a PIT-tag reader and bait weighing device, to record bait uptake by individual grey squirrels for optimising the delivery of a contraceptive bait. The hopper was designed to overcome some of the limitations of traditional PIT-tag systems, by improving battery life and the quality and quantity of data collected in the field. 5. In captive trials, the hopper proved to be highly effective at recording feeding visits by squirrels, as 95% of the visits could be attributed to a PIT-tag record. The hoppers measured the amount of bait removed per feeding visit to an accuracy of 0.1 g, with 97% of the bait taken from six hoppers attributed to a PIT-tag ID. In a field trial, the hoppers were effective at recording the feeding visits by grey squirrels in two woods, with 47 of the 51 PIT-tagged grey squirrels entering the hoppers. 6. The adaptability of the hopper design means that it has wider applications for wildlife management; in particular, efficacy studies for bait-delivered substances in the context of wildlife disease control and/or population reduction. Keywords: feeding behaviour, grey squirrel, contraceptives, biocides, microchip, Sciurus carolinensis, wildlife management, remote sensing

Constitutive upregulations of titin-based signalling proteins in KY deficient muscles.

An increase in the expression of stretch/stress response elements in fast and slow muscles has been previously described in a transcriptional profiling of KY deficient muscles. Here, we have characterized the induction of this titin-based family of signalling proteins in ky/ky muscles at the protein level. Changes in expression of MLP, MARP2 and Xin have been related to the onset of dystrophic and adaptive changes that operate in ky/ky muscles. Our results indicate that induction of this set of genes is an early consequence of the interference caused by the absence of the KY protein. A search of muscle profiles of mouse models revealed such molecular hallmark only in muscles subjected to a single bout of eccentric contractions and specific titin mutants. Based on the role of this family as titin-based stress response molecules, it is suggested that titin structural/signalling instability is common to ky and titin mouse mutants and eccentric contractions