G. J. Wilson

Bio: G. J. Wilson is an academic researcher from Animal and Plant Health Agency. The author has contributed to research in topics: Badger & Meles. The author has an hindex of 25, co-authored 38 publications receiving 2189 citations. Previous affiliations of G. J. Wilson include Food and Environment Research Agency & Central Science Laboratory.

A review of methods to estimate the abundance of terrestrial carnivores using field signs and observation

Abstract: This paper reviews field methods for estimating and monitoring the abundance of terrestrial carnivores that do not involve capture. Effective methods of monitoring abundance are important tools for the management and conservation of many species. The development of methods for carnivores presents particular challenges, as they are often secretive and widely dispersed. Nevertheless, a variety of approaches based on direct observations and quantification of field signs have been employed. These techniques are described in relation to carnivore ecology and resource implications, and the advantages and deficiencies of each are discussed with reference to case studies. Estindasvore G.ls J W033 Ga J. Rlah

Reliable microsatellite genotyping of the Eurasian badger (Meles meles) using faecal DNA

Abstract: The potential link between badgers and bovine tuberculosis has made it vital to develop accurate techniques to census badgers. Here we investigate the potential of using genetic profiles obtained from faecal DNA as a basis for population size estimation. After trialling several methods we obtained a high amplification success rate (89%) by storing faeces in 70% ethanol and using the guanidine thiocyanate/silica method for extraction. Using 70% ethanol as a storage agent had the advantage of it being an antiseptic. In order to obtain reliable genotypes with fewer amplification reactions than the standard multiple-tubes approach, we devised a comparative approach in which genetic profiles were compared and replication directed at similar, but not identical, genotypes. This modified method achieved a reduction in polymerase chain reactions comparable with the maximum-likelihood model when just using reliability criteria, and was slightly better when using reliability criteria with the additional proviso that alleles must be observed twice to be considered reliable. Our comparative approach would be best suited for studies that include multiple faeces from each individual. We utilized our approach in a well-studied population of badgers from which individuals had been sampled and reliable genotypes obtained. In a study of 53 faeces sampled from three social groups over 10 days, we found that direct enumeration could not be used to estimate population size, but that the application of mark-recapture models has the potential to provide more accurate results.

The status of tuberculosis in European wild mammals

Abstract: The current study is a contribution to Junta de Comunidades de Castilla-La Mancha (JCCM) PPIC10-0226-0243, Ministerio de Ciencia e Innovacion (MCINN) Plan Nacional I + D + i AGL2008-03875 and Fondo Europeo de Desarrollo Regional (FEDER) and to FP7 EU TB-STEP (212414) (Strategies for the eradication of bovine tuberculosis) Studies on diseases shared between domestic animals and wildlife are also supported by Santander and Fundacion Marcelino Botin Jose Luis Saez (Ministerio de Medio Ambiente, Rural y Marino, MARM) made valuable comments on the first draft PA is currently holding a Juan de la Cierva research contract awarded by the Ministerio de Ciencia e Innovacion – Fondo Social Europeo

Bacillus Calmette-Guérin vaccination reduces the severity and progression of tuberculosis in badgers

Abstract: Control of bovine tuberculosis (TB) in cattle has proven particularly challenging where reservoirs of infection exist in wildlife populations. In Britain and Ireland, control is hampered by a reservoir of infection in Eurasian badgers (Meles meles). Badger culling has positive and negative effects on bovine TB in cattle and is difficult, costly and controversial. Here we show that Bacillus Calmette-Guerin (BCG) vaccination of captive badgers reduced the progression, severity and excretion of Mycobacterium bovis infection after experimental challenge. In a clinical field study, BCG vaccination of free-living badgers reduced the incidence of positive serological test results by 73.8 per cent. In common with other species, BCG did not appear to prevent infection of badgers subjected to experimental challenge, but did significantly reduce the overall disease burden. BCG vaccination of badgers could comprise an important component of a comprehensive programme of measures to control bovine TB in cattle.

Mating system of the Eurasian badger, Meles meles, in a high density population.

Abstract: Badgers are facultatively social, forming large groups at high density. Group-living appears to have high reproductive costs for females, and may lead to increased levels of inbreeding. The extent of female competition for reproduction has been estimated from field data, but knowledge of male reproductive success and the extent of extra-group paternity remains limited. Combining field data with genetic data (16 microsatellite loci), we studied the mating system of 10 badger social groups across 14 years in a high-density population. From 923 badgers, including 425 cubs, we were able to assign maternity to 307 cubs, with both parents assigned to 199 cubs (47%) with 80% confidence, and 14% with 95% confidence. Age had a significant effect on the probability of reproduction, seemingly as a result of a deficit of individuals aged two years and greater than eight years attaining parentage. We estimate that approximately 30% of the female population successfully reproduced in any given year, with a similar proportion of the male population gaining paternity across the same area. While it was known there was a cost to female reproduction in high density populations, it appears that males suffer similar, but not greater, costs. Roughly half of assigned paternity was attributed to extra-group males, the majority of which were from neighbouring social groups. Few successful matings occurred between individuals born in the same social group (22%). The high rate of extra-group mating, previously unquantified, may help reduce inbreeding, potentially making philopatry a less costly strategy.

Predator interactions, mesopredator release and biodiversity conservation

Abstract: There is growing recognition of the important roles played by predators in regulating ecosystems and sustaining biodiversity. Much attention has focused on the consequences of predator-regulation of herbivore populations, and associated trophic cascades. However apex predators may also control smaller 'mesopredators' through intraguild interactions. Removal of apex predators can result in changes to intraguild interactions and outbreaks of mesopredators ('mesopredator release'), leading in turn to increased predation on smaller prey. Here we provide a review and synthesis of studies of predator interactions, mesopredator release and their impacts on biodiversity. Mesopredator suppression by apex predators is widespread geographically and taxonomically. Apex predators suppress mesopredators both by killing them, or instilling fear, which motivates changes in behaviour and habitat use that limit mesopredator distribution and abundance. Changes in the abundance of apex predators may have disproportionate (up to fourfold) effects on mesopredator abundance. Outcomes of interactions between predators may however vary with resource availability, habitat complexity and the complexity of predator communities. There is potential for the restoration of apex predators to have benefits for biodiversity conservation through moderation of the impacts of mesopredators on their prey, but this requires a whole-ecosystem view to avoid unforeseen negative effects. 'Nothing has changed since I began. My eye has permitted no change. I am going to keep things like this.' From 'Hawk Roosting', by Ted Hughes.

Noninvasive genetic sampling tools for wildlife biologists: a review of applications and recommendations for accurate data collection

Abstract: Noninvasive genetic sampling provides great potential for research and management applications in wildlife biology. Researchers can obtain DNA from a variety of sources including hair, feces, urine, feathers, shed skin, saliva, and egg shells without handling or observing animals. These samples can then be used to identify the presence of rare or elusive species, count and identify individuals, determine gender, and identify diet items, or samples can be used to evaluate genetic diversity, population structure, and mating system. We review the recent advancements and techniques used for identifying species, individuals, and gender. We also address the potential pitfalls of noninvasive genetic sampling and provide recommendations for laboratory- and field-based methods to improve the reliability and accuracy of data collected from noninvasive genetic samples.

Estimating animal density using camera traps without the need for individual recognition

Abstract: Summary 1Density estimation is of fundamental importance in wildlife management. The use of camera traps to estimate animal density has so far been restricted to capture–recapture analysis of species with individually identifiable markings. This study developed a method that eliminates the requirement for individual recognition of animals by modelling the underlying process of contact between animals and cameras. 2The model provides a factor that linearly scales trapping rate with density, depending on two key biological variables (average animal group size and day range) and two characteristics of the camera sensor (distance and angle within which it detects animals). 3We tested the approach in an enclosed animal park with known abundances of four species, obtaining accurate estimates in three out of four cases. Inaccuracy in the fourth species was because of biased placement of cameras with respect to the distribution of this species. 4Synthesis and applications. Subject to unbiased camera placement and accurate measurement of model parameters, this method opens the possibility of reduced labour costs for estimating wildlife density and may make estimation possible where it has not been previously. We provide guidelines on the trapping effort required to obtain reasonably precise estimates.

The adaptive value of sociality in mammalian groups

Abstract: According to behavioural ecology theory, sociality evolves when the net benefits of close association with conspecifics exceed the costs. The nature and relative magnitude of the benefits and costs of sociality are expected to vary across species and habitats. When sociality is favoured, animals may form groups that range from small pair-bonded units to huge aggregations. The size and composition of social groups have diverse effects on morphology and behaviour, ranging from the extent of sexual dimorphism to brain size, and the structure of social relationships. This general argument implies that sociality has fitness consequences for individuals. However, for most mammalian species, especially long-lived animals like primates, there are sizable gaps in the chain of evidence that links sociality and social bonds to fitness outcomes. These gaps reflect the difficulty of quantifying the cumulative effects of behavioural interactions on fitness and the lack of information about the nature of social relationships among individuals in most taxa. Here, I review what is known about the reproductive consequences of sociality for mammals.

Microsatellite genotyping errors : detection approaches, common sources and consequences for paternal exclusion

Abstract: Microsatellite genotyping errors will be present in all but the smallest data sets and have the potential to undermine the conclusions of most downstream analyses. Despite this, little rigorous effort has been made to quantify the size of the problem and to identify the commonest sources of error. Here, we use a large data set comprising almost 2000 Antarctic fur seals Arctocephalus gazella genotyped at nine hypervariable microsatellite loci to explore error detection methods, common sources of error and the consequences of errors on paternal exclusion. We found good concordance among a range of contrasting approaches to error-rate estimation, our range being 0.0013 to 0.0074 per single locus PCR (polymerase chain reaction). The best approach probably involves blind repeat-genotyping, but this is also the most labour-intensive. We show that several other approaches are also effective at detecting errors, although the most convenient alternative, namely mother-offspring comparisons, yielded the lowest estimate of the error rate. In total, we found 75 errors, emphasizing their ubiquitous presence. The most common errors involved the misinterpretation of allele banding patterns (n = 60, 80%) and of these, over a third (n = 22, 36.7%) were due to confusion between homozygote and adjacent allele heterozygote genotypes. A specific test for whether a data set contains the expected number of adjacent allele heterozygotes could provide a useful tool with which workers can assess the likely size of the problem. Error rates are also positively correlated with both locus polymorphism and product size, again indicating aspects where extra effort at error reduction should be directed. Finally, we conducted simulations to explore the potential impact of genotyping errors on paternity exclusion. Error rates as low as 0.01 per allele resulted in a rate of false paternity exclusion exceeding 20%. Errors also led to reduced estimates of male reproductive skew and increases in the numbers of pups that matched more than one candidate male. Because even modest error rates can be strongly influential, we recommend that error rates should be routinely published and that researchers make an attempt to calculate how robust their analyses are to errors.