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European Rabbits (european + rabbits)
Selected AbstractsHerbivory and plant growth rate determine the success of El Niño Southern Oscillation-driven tree establishment in semiarid South AmericaGLOBAL CHANGE BIOLOGY, Issue 12 2006MILENA HOLMGREN Abstract While climatic extremes are predicted to increase with global warming, we know little about the effect of climatic variability on biome distribution. Here, we show that rainy El Niño Southern Oscillation (ENSO) events can enhance tree recruitment in the arid and semiarid ecosystems of north-central Chile and northwest Peru. Tree-ring studies in natural populations revealed that rainy El Niño episodes have triggered forest regeneration in Peru. Field experiments indicate that tree seedling recruitment in Chile is much less successful than in Peru due mostly to larger mortality caused by herbivores. The dramatic impact of herbivores in Chile was derived from the combined result of slower plant growth and the presence of exotic herbivores (European rabbits and hares). The interplay of herbivory and climatic effects we demonstrated implies that rainy ENSO events may represent ,windows of opportunity' for forest recovery if herbivore pressure is minimized at the right moment. [source] The inadvertent introduction into Australia of Trypanosoma nabiasi, the trypanosome of the European rabbit (Oryctolagus cuniculus), and its potential for biocontrolMOLECULAR ECOLOGY, Issue 10 2005P. B. HAMILTON Abstract Wild rabbits (Oryctolagus cuniculus) in Australia are the descendents of 24 animals from England released in 1859. We surveyed rabbits and rabbit fleas (Spilopsyllus cuniculi) in Australia for the presence of trypanosomes using parasitological and PCR-based methods. Trypanosomes were detected in blood from the European rabbits by microscopy, and PCR using trypanosome-specific small subunit ribosomal RNA (SSU rRNA) gene primers and those in rabbit fleas by PCR. This is the first record of trypanosomes from rabbits in Australia. We identified these Australian rabbit trypanosomes as Trypanosoma nabiasi, the trypanosome of the European rabbit, by comparison of morphology and SSU rRNA gene sequences of Australian and European rabbit trypanosomes. Phylogenetic analysis places T. nabiasi in a clade with rodent trypanosomes in the subgenus Herpetosoma and their common link appears to be transmission by fleas. Despite the strict host specificity of trypanosomes in this clade, phylogenies presented here suggest that they have not strictly cospeciated with their vertebrate hosts. We suggest that T. nabiasi was inadvertently introduced into Australia in the 1960s in its flea vector Spilopsyllus cuniculi, which was deliberately introduced as a potential vector of the myxoma virus. In view of the environmental and economic damage caused by rabbits in Australia and other islands, the development of a virulent or genetically modified T. nabiasi should be considered to control rabbits. [source] Density-dependent reproduction in the European rabbit: a consequence of individual response and age-dependent reproductive performanceOIKOS, Issue 3 2004Heiko G. Rödel Density dependence of reproduction has generally been proposed to be caused by habitat heterogeneity and by the individual response of reproductive output. However, a further mechanism might generate density dependence of average reproductive rates. High density situations might be associated with a high proportion of first-season breeders which often show a principally lower reproductive performance. We tested for the existence of the latter mechanism as well as for density-dependent individual changes of reproductive effort in a population of European rabbits living in a homogeneous grassland habitat. The study was conducted over a period of eleven years. Overall, a strong relationship between mean reproductive rates and the breeding density of females was apparent. All necessary conditions for the presence of a density-dependent effect caused by age-dependent reproduction were fulfilled: Fluctuations of breeding density were paralleled by variations in the proportion of one-year-old females. These one-year-old, first-season breeders showed a consistently lower reproductive performance than older females, which might be caused by their lower body mass and their lower social rank. However, we also found strong evidence for density-dependent response of individual reproductive effort: Individual changes in fecundity over successive years were explained by changes in the breeding density of females. The results suggest that density dependence of reproduction in European rabbits is due to an interaction of age-dependent reproductive performance together with short-term fluctuations in breeding density, and a density-dependent, individual based response of reproductive rates. We further conclude that the lower reproductive performance of first-season breeders in age-structured animal populations may contribute substantially to interannual, and under particular circumstances to density-dependent variations of mean reproductive rates. [source] Improving predictions of the location and use of warrens in sensitive rabbit populationsANIMAL CONSERVATION, Issue 5 2009I. C. Barrio Abstract The location and use of warrens is a key factor in the population dynamics of the European rabbit Oryctolagus cuniculus L., which can influence stability and persistence in the long term. Within the species' original distribution range, its numbers have declined sharply in recent decades, which is a serious problem for the conservation of Mediterranean ecosystems. Artificial warrens are commonly used to bolster rabbit populations and the characterization of natural warrens in those areas might improve their efficiency. In this study, we use binomial generalized linear models to identify the factors associated with the location and use of warrens in a low-density area and we evaluate the effect of including the spatial structure of the data in the model. In addition, we generate a map that predicts the most suitable areas for artificial warrens. Contrary to what was expected, habitat variables are only secondary factors, and the location and use of warrens is influenced mainly by spatial factors, such as proximity to nearby warrens. Furthermore, the aggregated spatial pattern of warrens suggests that, at the local scale, for example, the hunting estate, intra-specific interactions might be playing a primary role in these low-density populations. To identify the most suitable sites for artificial warrens and, thereby, improve the efficiency of artificial warren building for conservation purposes, information about spatial structures should be included in models predicting natural warrens of European rabbits. [source] Origin of rabbit (Oryctolagus cuniculus) in China: evidence from mitochondrial DNA control region sequence analysisANIMAL GENETICS, Issue 2 2003J.-R. Long Summary A fragment of mitochondrial DNA (mtDNA) control region (,700 bp) was sequenced in 104 individuals from 20 breeds (three Chinese domestic breeds, five recently derived breeds and 12 introduced breeds) of domestic rabbits, Oryctolagus cuniculus. Nineteen sites were polymorphic, with 18 transitions and one insertion/deletion, and eight haplotypes (A1, A2, A3, A4, A5, A6, A7 and A8) were identified. Haplotype A1 was the most common and occurred in 89 individuals. In the 25 Chinese rabbits, only haplotype A1 was observed, while four haplotypes (A1, A3, A5 and A6) were found in 26 recently derived individuals. Haplotype A2 was shared by seven individuals among three introduced strains. The other six haplotypes accounted for 0.96,1.92% of the animals. Combined with the published sequences of European rabbits, a reduced median-joining network was constructed. The Chinese rabbit mtDNAs were scattered into two clusters of European rabbits. These results suggest that the (so-called) Chinese rabbits were introduced from Europe. Genetic diversity in Chinese rabbits was very low. [source] | ||||||||||