Developmental instability and body condition in rodents: industrialized agriculture disturbances in anthromes from central Argentina

Abstract

Among human activities agriculture is one of the main drivers of biodiversity loss worldwide in recent decades. The effects of agricultural intensification on vertebrate populations may vary depending on their habitat requirements. The effect of environmental and/or genetic stress on populations can be assessed using fluctuating asymmetry and body condition of animals. We implemented both linear and geometric morphometric methods to assess the influence of agricultural intensification on three native rodent species. For this, we evaluated different stress indicators on skulls and mandibles (fluctuating asymmetry, centroid size and scaled mass index) of three species of small mammals at borders of rural roads in agroecosystems in central Argentina. We explored the impact of intensification using variables at different scales: landscape level, assessing complexity through functional and structural heterogeneity; and local level, through vegetal volume of the border. We found species-specific responses, where the most sensitive species was Calomys venustus, which showed individuals with lower developmental stability and body condition in simple landscapes and low-quality habitats. Akodon azarae responded in an intermediate manner to both size and mass index indicators, while the species Calomys musculinus was the least affected, with changes only in body condition observed, with larger individuals in more complex landscapes. Our results suggest that the impact of agricultural intensification on small mammals varies according to their habitat requirements and the landscape heterogeneity. This study shows the importance of considering both local and landscape variables to propose management measures for biodiversity conservation in cropland anthromes.