Invasion and eradication of the American mink in the Atlantic Islands National Park (NW Spain) a retrospective analysis

Alien predators exert severe effects on island ecosystems, and their eradication from island habitats may therefore be necessary to conserve the native biota. Efforts are being made to eradicate the American mink (Neovison vison) from the Atlantic Islands of Galicia National Park (NW Spain), a protected site inhabited by vulnerable island fauna. We applied a molecular genetic approach to elucidate the source of the invaders and to evaluate the effectiveness of the trapping programme. We collected mink scats in the field and obtained tissue samples from culled mink. Populations of feral mink were known to be present in coastal areas close to the National Park archipelagos in the 1980–1990s. However, the molecular findings suggest that these populations were not the main source of the mink populations that colonized the islands during the 2000s. Recent releases from farms directly on to the islands are a more likely source of these invaders. Genetic analysis suggested that mink reproduced successfully on the islands and were relatively isolated from other mainland populations. The findings also suggest that most of the culled mink were juveniles, probably because it was more difficult to catch adults. Since mink are short-lived animals, it seems that eradication may also be achieved when a large proportion of juveniles are culled in isolated and small populations. © 2016, Springer International Publishing Switzerland

Low persistence in nature of captive reared rabbits after restocking operations

© 2015, Springer-Verlag Berlin Heidelberg. The use of restocking of animals is common practice in the management of populations subject to hunting or recreational fishing. This practice encompasses the release of large numbers of individuals in an area where the species already exists, and thus it can have detrimental genetic impacts on the target populations, especially when captive-reared animals are involved. To better understand this practice and its conservation implications, we chose as a model the wild rabbit (Oryctolagus cuniculus), a species of high economic and ecological importance, and often under intense management for hunting or conservation purposes, particularly after the large decline caused by rabbit hemorrhagic disease in the 90′s. We studied the genetics of rabbit populations in an area where restocking with captive, wild–domestic hybrids was common. We collected a total of 503 samples from 15 hunting estates that had experienced differing restocking levels, as well as from five locations with no historical restocking and five game farms. All samples were analyzed to determine the mitochondrial DNA (mtDNA) lineage typical of the two European wild rabbit subspecies and domestic rabbit. Game farms and never restocked populations were very different in their haplotypic composition. In restocked areas, the proportion of the domestic lineage was higher when releases were recent and repeated, but this declined rapidly over time, in part due to selective removal by hunting. The extended use of this practice, considering the pronounced genetic and genotypic differences between domestic and wild rabbits, represents a potential danger to natural populations, especially given the marked decrease in wild rabbit numbers experienced in recent years in its original distribution range

European rabbit hunting: Management changes and inertia in the governance system in a period of population fluctuations

The recreational use of natural resources requires the implementation of sustainable management systems. However, the existence of socioeconomic interests and the difficulty involved in applying evidence-based criteria often hinder this implementation. The European wild rabbit (Oryctolagus cuniculus) is an appropriate case with which to study the recreational hunting governance systems. This species has, in recent decades, undergone important population changes in its native area, the Iberian Peninsula, where it plays a triple role as a game, pest and key ecological species. The rabbit is consequently intensively managed for hunting purposes, for the conservation of rabbit-dependent predators and in order to mitigate damage to crops. In this paper, we study the governance system of rabbit hunting through the use of questionnaire surveys distributed to managers working for Spanish regional governments. We repeated the survey in 2001 and 2016 in order to evaluate how the system had evolved over a 15-year period of important changes in rabbit population abundance. We found two different responses to these changes. The growth of rabbit populations in provinces in which rabbits cause crop damage in farmland areas has been dealt with an increase in hunting pressure, derived from both administrative decisions and hunters’ management. However, in provinces where rabbit populations have sharply declined in natural vegetation (non-farmland) areas, the management seems to be driven mostly by inertia, with a high influence of tradition and little use of evidence on administrative decisions. Hunters in these provinces have changed their management practices to little or no extent, where even the high importance of rabbit hunting and its (moderate) economic importance do not appear to provide an incentive for the change required.This study is a contribution of the CGL2013-43197-R project (I + D National Plan), funded by the Spanish Ministry of Science and Innovation

The paradox of endangered European rabbits regarded as pests on the Iberian Peninsula: Trends in subspecies matter

The European rabbit Oryctolagus cuniculus faces a paradoxical situation in its native range on the Iberian Peninsula. While many populations have declined sharply due to a new variant of the rabbit haemorrhagic disease virus (RHDV-b), others remain healthy. The latter populations, which flourish mostly on farmland, cause significant crop damage. We explored if this difference could be related to the existence of the 2 rabbit subspecies (O. c. algirus and O. c. cuniculus) that coexist allopatrically on the Iberian Peninsula. Potential differences in population trends between rabbit subspecies may also be relevant in assisting the conservation of endangered rabbit-dependent predators which mainly occur in the distribution area of O. c. algirus. To test this, we assessed rabbit trends after the outbreak of RHDV-b by an online questionnaire to the senior administrative officers of all provincial official game departments throughout peninsular Spain (n = 47). A generalized negative trend was reported by officers in the distribution area of O. c. algirus, while a more stable or even positive trend was reported in the distribution area of O. c. cuniculus. We point to the need for establishing a long-term rabbit population monitoring programme on the Iberian Peninsula to further confirm the observed patterns, but also to contribute to evidence-based management decision-making. Our results suggest a need to apply different management systems for each rabbit subspecies.P.H.V. was supported by a grant (FPU17/04821) from the Spanish Ministry of Science, Innovation and Universities. This study was partially funded by Projects 201810I026 and 202010E004 financed by CSIC