RESUMO
Identifying the environmental factors that determine the occurrence of invasive species is essential in defining and implementing effective control campaigns. Here, we applied multi-season occupancy models to analyze American mink (Neogale vison) track data collected using 121 floating rafts, as a function of factors occurring at multiple spatial scales. Our overall aim was to identify those factors that determine the use, colonization or abandonment of rafts by free ranging individuals found in western Macedonia, Greece. We found that increasing values of shrubs and rock cover at the micro-habitat scale were positively associated with the species' probability of raft use, as was the density of medium-sized rivers at the landscape scale. Colonization was found to increase with increasing amounts of shrub and reed cover; however, both variables were not informative. Conversely, the distance from the nearest fur farm was highly informative in predicting raft abandonment by the species. Effective control actions may require removal by trapping along rocky or densely vegetated riverbanks or lake shores located in the vicinity of the established fur farms in the area. Habitat management, although possible, may be difficult to implement due to the ability of the species to adapt. Finally, fur farms should maximize security and establish an early warning and rapid eradication system in case of future escapes.
Assuntos
Ecossistema , Espécies Introduzidas , Vison , Animais , Grécia , Vison/fisiologia , Dinâmica Populacional , Estações do AnoRESUMO
The Eurasian Black Vulture is a globally threatened raptor that in Southeast Europe only occurs in an isolated population in Greece. We examined the population viability for the species under demographic fluctuations and conservation scenarios. The current population showed no possibility of extinction for the next 100 years. However, simulated scenarios showed that the most important factor affecting the viability of the species was medium and high poisoning, leading to 94.8% and 100% probability of extinction, respectively. Furthermore, high reduction of supplementary feeding highlighted an 18.6% extinction possibility. Also, a high increase of wind farms in the area may result in 17.4% extinction possibility. Additionally, the non-establishment of the feeding station in 1987 in the study area would have resulted in an extinction risk of 7%. The species can be translocated to the Olympus National Park by releasing 80 juveniles over 10 years. The implementation of the conservation scenarios concerning the establishment of a supplementary feeding site network, and the reintroduction of the Eurasian Black Vulture in its historic range, along with the elimination of threats posed by poisoning, low food availability, and wind farms would increase the probability of the species persistence and allow the population to become a source for dispersal across Southeast Europe.