Lack of detectable genetic isolation in the cyclic rodent Microtus arvalis despite large landscape fragmentation owing to transportation infrastructures

Abstract Although roads are widely seen as dispersal barriers, their genetic consequences for animals that experience large fluctuations in population density are poorly documented. We developed a spatially paired experimental design to assess the genetic impacts of roads on cyclic voles (Microtus arvalis) during a high-density phase in North-Western Spain. We compared genetic patterns from 15 paired plots bisected by three different barrier types, using linear mixed models and computing effect sizes to assess the importance of each type, and the influence of road features like width or the age of the infrastructure. Evidence of effects by roads on genetic diversity and differentiation were lacking. We speculate that the recurrent (each 3–5 generations) episodes of massive dispersal associated with population density peaks can homogenize populations and mitigate the possible genetic impact of landscape fragmentation by roads. This study highlights the importance of developing spatially replicated experimental designs that allow us to consider the large natural spatial variation in genetic parameters. More generally, these results contribute to our understanding of the not well explored effects of habitat fragmentation on dispersal in species showing “boom-bust” dynamics

Selección del hábitat y permeabilidad del territorio para el lince ibérico ("Lynx pardinus") en Andalucía: influencia del estado de comportamiento y de la resolución cartográfica

Los esfuerzos de conservación sobre las poblaciones del amenazado lince ibérico (Lynx pardinus) y la reintroducción de ejemplares para expandir las poblaciones hacia sus áreas de distribución histórica hacen necesario evaluar la potencialidad del territorio para albergar poblaciones estables y para facilitar el movimiento de individuos entre ellas. Con este objetivo, se han analizado 43 897 localizaciones proporcionadas por collares GPSGSM de 48 linces en Andalucía. Las localizaciones se clasificaron en dos grupos según el estado de comportamiento de los animales (territorial/dispersivo), aplicando a cada grupo una función de selección de recursos para determinar la probabilidad de selección de cubiertas forestales y no forestales, caracterizadas mediante el Sistema de Información de Ocupación del Suelo para Andalucía (escala 1:10 000) y el Mapa Forestal de España (escala 1:50 000). Los resultados indican mayor plasticidad de individuos dispersivos en el uso de las cubiertas respecto a los ejemplares territoriales. Permiten identificar áreas con elevada calidad del hábitat fuera de zonas de distribución actual, así como una permeabilidad al movimiento relativamente baja alrededor de la población Doñana-Aljarafe. La cartografía empleada no mejora sin embargo el ajuste de modelos similares con cartografías de menor resolución espacial y temática. Los análisis realizados muestran la influencia del estado de comportamiento de los individuos en el uso del territorio y la importancia de seleccionar cartografía adecuada a los objetivos del estudio. Al tiempo sugieren áreas preferentes para establecer medidas de gestión del territorio ocupado por las actuales y posibles futuras poblaciones y de los paisajes heterogéneos que las separan

Feral American mink (Neogale vison) continues to expand its European range: time to harmonize population monitoring and coordinate control

1. The American mink Neogale vison is an invasive alien species in Europe that threatens endemic biodiversity and can transmit zoonotic diseases, including the SARS-CoV-2 virus. The last attempt to map the geographic range of this species in Europe, at continental scale, dates back to 2007. 2. We aimed to update the distribution map of the feral American mink and assess its temporal trends. The information we collected was critically analysed with the aim of improving future monitoring protocols and data collection. 3. We gathered and standardised data from 34 databases, covering 32 countries. Through 3 five-year periods from 2007 to 2021, changes in range size, hunting bags and capture statistics were analysed. We also reviewed the current situation of mink farming in the different European countries and recorded population control schemes. 4. The American mink is now widespread in the Baltic States, France, Germany, Iceland, Ireland, Poland, Scandinavia, Spain and the UK. The species is reported to be absent in some areas (e.g. parts of the UK, Iceland and Norway). Data are deficient for several countries, mainly in south-eastern Europe. These findings indicate that, during the last 15 years, the species has continued to spread across the continent, increasing its potential extent of occurrence in most countries. Our effort to collect and harmonise data across international borders highlighted information gaps and heterogeneity in data quality. 5. Updated distribution data on the species provided here will aid risk assessment and risk management policies. These actions require a coordinated effort for population monitoring at continental level. Monitoring effort and data collection should be intensified in south-eastern Europe to improve data on the current distribution of this invasive species.This work was made possible thanks to the ENETWILD project (www.enetwild.com) funded by EFSA (www.efsa.europa.eu) (“Wildlife: collecting and sharing data on wildlife populations, transmitting animal disease agents”, contract number: OC/EFSA/ALPHA/2016/01). This study also benefited from the Invasion Dynamics Network (InDyNet), the AlienCSI CA17122 COST Action funded by the European Cooperation in Science and Technology and the hunting associations of the German Federal States within WILD. Project reference PID2019-111699RB-I00 (National Research Program of Spain).Peer reviewe