Seasonal Drought and Habitat Disturbance Shaping Foraging Efficiency and Social Behavior in Small Grassland Mammals

Abstract

The grasslands are facing increasing threats from seasonal droughts and anthropogenic disturbances to habitat, which significantly affect the behavioral ecology of small mammals. The objective of this study was to determine the effects of both seasonal drought and anthropogenic disturbances in habitats on the foraging efficiency and social behavior of small grassland mammals in natural or semi-natural grassland ecosystems. Disturbances were classified into undisturbed, moderately disturbed, and highly disturbed areas based on vegetation density, grazing levels, soil disturbance, and human activities. Data collection involved behavioral observations using methods such as focal sampling, direct observation, and use of camera traps. Various parameters were considered, including food-searching time, feeding duration, movement distance, aggressive territoriality, vigilance behavior, group cohesion, and grooming behavior. The results indicate that there were notable changes in animal behavior under high levels of environmental stress. For example, mammals from highly stressed ecosystems showed increased foraging effort, taking an average of 13.5 ± 1.7 minutes and covering an average of 58.8 ± 4.4 meters, with a lower frequency of food consumption, averaging 7 events per day. Regarding social behavior, it was noted that animals from such habitats were less tolerant, engaging in higher levels of territory defense (9.7 ± 0.8 events per day) and higher vigilance levels (12.6 ± 1.1 events per hour), while group bonding (3.4 ± 0.4) and grooming activity (3.1 ± 0.4 per day) dropped significantly. According to statistical analysis, there was a negative correlation between drought intensity and foraging efficiency, and a positive correlation between habitat stress and stress-related social behavior.