Sloth bears help shape India’s dry forests as unlikely seed dispersers

Sloth bears, often overlooked, play a vital role in shaping India's dry deciduous forests, according to a recent study published by Mongabay India. These foraging mammals, which roam the mountainous regions of Rajasthan, help disperse seeds and influence plant regeneration. Researchers from the Wildlife Institute of India, Mohanlal Sukhadia University, and the Department of Zoology at Udaipur conducted a study on the impact of sloth bears on forest dynamics.

In their investigation, the team analyzed 180 droppings or scats of sloth bears (Melursus ursinus) to understand the animals' dietary habits. The findings revealed that the bears' diet changed significantly between winter and summer. During the winter months, ants dominated the bears' diet, appearing in over 80% of the scats. In contrast, termites were the most prevalent food source during the summer season.

The most critical food sources for sloth bears were donkey berry (Grewia flavescens) throughout the year, with Ziziphus nummularia preferred during the winter and Cassia fistula favored in the summer. This strong shift in diet was a surprising revelation for the researchers, as previous studies in semi-arid regions indicated that sloth bears consumed a significant amount of fruits during summer.

Study co-author Vijay Kumar Koli from Mohanlal Sukhadia University further emphasized the adaptability of these bears, stating that their dietary changes were a response to the availability of food sources. To test whether sloth bears helped in seed dispersal, the researchers monitored the germination of eight plant species most important in the bears' diet. The study demonstrated that sloth bears significantly contribute to seed dispersal and influence the regeneration of plant species in India's dry deciduous forests.