Southwestern Water Vole

The southwestern water vole or southern water vole (Arvicola sapidus) is a large amphibious vole native to most of France and southwestwards through Spain and Portugal. It is listed on the IUCN Red List as a Near Threatened species. == Reproductive cycle == The reproductive cycle of the southwestern water vole varies seasonally and geographically, with the most intense reproductive activity occurring from March through October, peaking between April and June. Although reproduction occurs year-round, a distinct reduction in reproductive activity occurs from November through February, coinciding with lower temperatures and shorter day lengths. Females become sexually mature when they reach a weight of around 140 grams (4.9 oz), with larger individuals typically having higher reproductive success. On average, females produce litters of about four offspring (range 1–7). Litter size is directly correlated with maternal body weight, with heavier females tending to have larger litters. Gestation occurs throughout nearly the entire year, though the frequency varies significantly, with fewer pregnancies observed during the winter months. Intrauterine mortality affects about 5% of embryos and is more common in older females. The reproductive life of adult females may include multiple litters annually, with some individuals potentially having up to six litters over…