Understanding the drivers underlying fluctuations in the size of animal populations is central to ecology, conservation biology, and wildlife management. Reliable estimates of survival probabilities are key to population viability assessments, and patterns of variation in survival can help inferring the causal factors behind detected changes in population size. We investigated whether variation in age- and sex-specific survival probabilities could help explain the increasing trend in population size detected in a small, discrete population of bottlenose dolphins off the east coast of Scotland.
View Article and Find Full Text PDFWe studied the prevalence and genetic diversity of malaria parasites in the poorly investigated spotless starling (Sturnus unicolor) breeding in central Spain, aiming to describe the phylogenetic relationships among them and with other haemosporidians infecting the genus Sturnus. A total of 180 nestlings and 180 adult individuals from four different breeding seasons were screened for haemosporidian parasites using a nested PCR approach for the genera Plasmodium and Haemoproteus. Although the malaria prevalence ranged between years, the overall prevalence was 6.
View Article and Find Full Text PDFIdentifying the processes that drive changes in the abundance and distribution of natural populations is a central theme in ecology and evolution. Many species of marine mammals have experienced dramatic changes in abundance and distribution due to climatic fluctuations and anthropogenic impacts. However, thanks to conservation efforts, some of these species have shown remarkable population recovery and are now recolonizing their former ranges.
View Article and Find Full Text PDFGenetic data can provide a powerful tool for those interested in the biology, management and conservation of wildlife, but also lead to erroneous conclusions if appropriate controls are not taken at all steps of the analytical process. This particularly applies to data deposited in public repositories such as GenBank, whose utility relies heavily on the assumption of high data quality. Here we report on an in-depth reassessment and comparison of GenBank and chromatogram mtDNA sequence data generated in a previous study of Baltic grey seals.
View Article and Find Full Text PDFReproduction in opportunistically breeding bird species has traditionally been considered non-seasonal with individuals taking advantage of favourable environmental conditions as they arise. However, some studies imply that this opportunistic breeding may be superimposed on an underlying seasonality, which has effects on the readiness to breed when conditions are favourable. The zebra finch (Taeniopygia guttata) is the classic opportunistic breeder and widely used as such in studies.
View Article and Find Full Text PDFWe describe polymerase chain reaction primers and amplification conditions for 13 microsatellite DNA loci isolated from two bisexual species of whiptail lizards Aspidoscelis costata huico and Aspidoscelis inornata. Primers were tested on either 16 or 48 individuals of A. c.
View Article and Find Full Text PDFMany studies have demonstrated influences of climatic variation on a variety of ecological processes, however, its impact on the potent evolutionary force of sexual selection has largely been ignored. The intensity of sexual selection is a fundamental parameter in animal populations, which depends upon the degree of polygamy and will probably be influenced by the impact of local climatic variation upon 'environmental potential for polygamy'. Here, we provide evidence of a direct effect of local climatic variation on the intensity of sexual selection, by showing a clear correlation between local weather conditions and inter-annual changes in the degree of polygamy in a long-term study of colonially breeding grey seals (Halichoerus grypus).
View Article and Find Full Text PDFWrens of the genus Thryothorus comprise over a third of the species diversity in the family Troglodytidae. In addition to this species diversity, these wrens vary in a number of behavioral characteristics, in particular in the presence and structure of vocal duets, which makes them an interesting target for comparative evolutionary ecological and behavioral study. However, no phylogenetic hypothesis for this group-which would provide a sound basis for comparative analysis-is currently available.
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