Factors influencing Willow Tit Poecile montanus site occupancy: a comparison of abandoned and occupied woods

The British Willow Tit Poecile montanus kleinschmidti underwent a decline of 85% between 1970 and 2003. The cause of this decline is unknown. However, several hypotheses have been put forward to account for it: competition from other tit species, predation by Great Spotted Woodpeckers Dendrocopos major and habitat change. In order to test these, woods that are currently occupied by Willow Tits were paired with woods (within 50 km) that had been abandoned by Willow Tits five or more years previously. Point counts for other tit species (potential competitors) and woodpecker species (potential predators) were carried out at ten evenly spaced points throughout each wood. Habitat variables were collected within a 50-m radius of where a Willow Tit was located (in the occupied woods) or where maps showed a Willow Tit had been located (for abandoned woods). No evidence was found for differences in numbers of potential competitor or potential predator species in abandoned and occupied woods. Soil water content was found to be higher at occupied sites. No other habitat features differed between the two categories of site. The drying up of British woods could therefore be implicated in the Willow Tit decline and this warrants further investigation.     

Growth and demography of a re‐introduced population of White‐tailed Eagles Haliaeetus albicilla

White‐tailed Eagles Haliaeetus albicilla became extinct in Britain in 1918 following prolonged persecution. Intensive conservation efforts since the 1970s have included the re‐introduction of the species to Britain through two phases of release of Norwegian fledglings in western Scotland in 1975–85 and 1993–98. Population growth and breeding success have been monitored closely to the present day, aided by the use of patagial tags to individually mark most released birds as well as a high proportion of wild‐bred nestlings. This study reviews the growth and demography of this re‐introduced population, and makes comparisons with other European populations. For the first time, we compare the demographic rates of released and wild‐bred birds in the Scottish population. Breeding success in the Scottish population has increased over time as the average age and experience of individuals in the population have increased, and success tends to be higher where one or both adults are wild‐bred. Current levels of breeding success remain low compared with some other populations in Europe, but similar to those in Norway where weather conditions and food availability are likely to be most similar. Survival rates in Scotland are similar to those recorded elsewhere, but survival rates of released birds are lower than those of wild‐bred birds, especially during the first 3 years of life. Despite the effect of lower survival rates of released birds in limiting overall population growth rate, the recent rate of growth of the Scottish population remains high relative to other recovering populations across Europe. Differences in demographic rates of wild‐bred and released birds suggest that in future re‐introduction programmes, steps to maximize the success and output of the earliest breeding attempts would help ensure the most rapid shift to a population composed largely of wild‐bred birds, which should then have a higher rate of increase.     

Identification and functional characterization of effectors in expressed sequence tags from various life cycle stages of the potato cyst nematode Globodera pallida

In this article, we describe the analysis of over 9000 expressed sequence tags (ESTs) from cDNA libraries obtained from various life cycle stages of Globodera pallida . We have identified over 50 G. pallida effectors from this dataset using bioinformatics analysis, by screening clones in order to identify secreted proteins up-regulated after the onset of parasitism and using in situ hybridization to confirm the expression in pharyngeal gland cells. A substantial gene family encoding G. pallida SPRYSEC proteins has been identified. The expression of these genes is restricted to the dorsal pharyngeal gland cell. Different members of the SPRYSEC family of proteins from G. pallida show different subcellular localization patterns in plants, with some localized to the cytoplasm and others to the nucleus and nucleolus. Differences in subcellular localization may reflect diverse functional roles for each individual protein or, more likely, variety in the compartmentalization of plant proteins targeted by the nematode. Our data are therefore consistent with the suggestion that the SPRYSEC proteins suppress host defences, as suggested previously, and that they achieve this through interaction with a range of host targets.     

Habitat use by Hen Harriers Circus cyaneus on Orkney: implications of land-use change for this declining population

The use of habitats by hunting Hen Harriers Circus cyaneus just prior to the settlement period was investigated on Orkney, where numbers have declined by 70% over the last 20 years. Both males and females hunted over areas that were closer to subsequent breeding territories. Neither sex differed in the amount of time they hunted over areas dominated by either intensive pasture, moorland or rough grazing. However, male hunting was significantly related to the amount of unmanaged grass habitat with a litter layer. Female hunting was related negatively to vegetation height, and to the prevalence of both Heather Calluna vulgaris and managed grass; after controlling for these habitat features, female hunting also tended to be associated negatively with Common Starling Sturnus vulgaris abundance. Dramatic changes in land use on Orkney have occurred over the last 40 years, with increases in the amount of intensive pasture and decreases in the amount of rough grazing. These changes, coupled with a doubling in sheep Ovis aries densities over the last 20 years, are likely to have reduced the amount of unmanaged grass. These changes will have been detrimental to hunting male Harriers by reducing the amount of food they can supply to the females prior to egg laying and during the incubation period.     

Characterization of MTNR1A gene in terms of genetic variability in a panel of subtemperate and subtropical Indian sheep breeds

Seasonality of animals is an important adaptive trait for successful survival and production during limited food availability and extreme environmental conditions. Photoperiodic changes in day length are utilized by these seasonal animals as an important environmental cue for regulating their annual rhythms of reproduction cycles. Melatonin is an important hormone which is secreted by the pineal gland in proportion to darkness and its effect is mediated by melatonin receptor subtypes, principally MTNR1A. In the present study, polymorphism in the coding sequence at two important SNPs (C606T and G612A), known to be markers for out of season breeding in sheep were studied by PCR-RFLP in a panel of four breeds of sheep from subtemperate and subtropical arid conditions, respectively. The frequencies of ‘G’ and ‘A’ alleles with reference to G612A SNP did not differ considerably among all the breeds of sheep. Frequency of ‘T’ allele of the C606T SNP was found to be dominantly higher in subtemperate sheep breeds in comparison to subtropical sheep breeds. Identified SNPs in the coding region were mostly synonymous and did not lead to any change in conformation of the MTNR1A receptor protein.     

Hybridization between distant lineages increases adaptive variation during a biological invasion: stickleback in Switzerland

The three‐spined stickleback is a widespread Holarctic species complex that radiated from the sea into freshwaters after the retreat of the Pleistocene ice sheets. In Switzerland, sticklebacks were absent with the exception of the far northwest, but different introduced populations have expanded to occupy a wide range of habitats since the late 19th century. A well‐studied adaptive phenotypic trait in sticklebacks is the number of lateral plates. With few exceptions, freshwater and marine populations in Europe are fixed for either the low plated phenotype or the fully plated phenotype, respectively. Switzerland, in contrast, harbours in close proximity the full range of phenotypic variation known from across the continent. We addressed the phylogeographic origins of Swiss sticklebacks using mitochondrial partial cytochrome b and control region sequences. We found only five different haplotypes but these originated from three distinct European regions, fixed for different plate phenotypes. These lineages occur largely in isolation at opposite ends of Switzerland, but co‐occur in a large central part. Across the country, we found a strong correlation between a microsatellite linked to the high plate ectodysplasin allele and the mitochondrial haplotype from a region where the fully plated phenotype is fixed. Phylogenomic and population genomic analysis of 481 polymorphic amplified fragment length polymorphism loci indicate genetic admixture in the central part of the country. The same part of the country also carries elevated within‐population phenotypic variation. We conclude that during the recent invasive range expansion of sticklebacks in Switzerland, adaptive and neutral between‐population genetic variation was converted into within‐population variation, raising the possibility that hybridization between colonizing lineages contributed to the ecological success of sticklebacks in Switzerland.