Relatedness dynamics and sex-biased dispersal in a seasonal cycle of corn mice from intensively managed agroecosystems

Abstract

The sex-biased dispersal and kinship dynamics are important factors shaping the spatial distribution of individuals and are key parameters affecting a variety of ecological and evolutionary processes. Here, we studied the spatial distribution of related individuals within a population of corn mice Calomys musculinus in a seasonal cycle to infer dispersal patterns. The sampling was carried out from spring 2005 to winter 2006 in field borders of intensively managed agroecosystems. Genotyping data from 346 individuals with 9 microsatellites showed spatial genetic structure (SGS) was weak for males, but not for females. The results indicate a complex spatial kinship dynamic of related females across all seasons. Which, contrary to our expectations, dispersal distances decrease with the increase of the population abundance. Meanwhile, male dispersal distances were greater when population abundance increased and thus the availability of active females. Males disperse greater distances to mate and sire offspring with distant females as a possible inbreeding avoidance mechanism. This study shows that C. musculinus is capable of much greater scattering distances than previously reported and that dispersal occurs fluidly and without barriers across the agroecosystem. The indirect benefit of dispersal on individual fitness could be related to relaxing the competition in the natal area and increasing the mating rate. Our study highlights the value of combining genetic relatedness, fieldwork observations, and behavioural data to estimate dispersal at a fine geographical scale.

Shifting human-rodent interfaces under climate change: modeling the distribution of the reservoir for Junin virus and associated drivers

“…Argentina, covering a land area of 2,780,400 km 2 and 3,694 km north-south span, has fertile lands, mainly in the central and the eastern pampas plains and irrigated valleys at the base of the Andes Mountains [29]. Agriculture is one of its principal economic activities, consisting of monocultures of corn, soybean, sunflower, and wheat [18]. The human population is predicted to grow from the current 46 million to 73.4 million by 2100 [30,31].…”

“…The abundance of C. musculinus changes seasonally, driven by natural climatic variations and land-use practices that affect resource availability [18]. Moreover, corn crops and land-surface temperature are positive predictors of the rodents' abundance.…”

“…It occupies a wide variety of habitats, like natural grasslands, shrub steppes, crop field borders, and human-disturbed peri- domestic environments such as wastelands, railroads, and urban garbage dumps [16,17]. The abundance of C. musculinus changes seasonally, driven by natural climatic variations and land-use practices that affect resource availability [18]. Moreover, corn crops and land-surface temperature are positive predictors of the rodents’ abundance.…”