Livestock grazing influences insect populations in the Himalayas

by Ranjini Raghunath, Indian Institute of Science
Feb. 20, 2025

Domestic grazers are increasingly replacing wild herbivores in ecosystems around the world, leading to insidious changes in soil characteristics and vegetation patterns. A long-term study carried out in the Spiti valley of the Himalayas shows that this replacement can drastically influence the numbers of ground-dwelling arthropods like spiders, as well as that of ticks and mites that can spread vector-borne diseases.

The study found that areas grazed by livestock had greatly reduced spider populations, and larger numbers of grasshoppers and disease carriers like ticks and mites.

“Spiders are predators; their ecological roles are similar to wolves, lions, and tigers. A low abundance of spiders can release grasshoppers from predator control, and lead to many downstream changes in an ecosystem. Together, these effects alter material and energy flow,” says Sumanta Bagchi, Associate Professor at the Centre for Ecological Sciences (CES), Indian Institute of Science (IISc) and corresponding author of the study published in Ecological Applications.

Bagchi and his team have been studying the effects of replacing wild herbivores like the yak and ibex with livestock like cattle and sheep in the Spiti valley for more than 15 years. “Wild herbivores were once ubiquitous across the Earth. Now, they are restricted to a few parks and reserves. Everywhere else, domesticated animals are now dominant,” Bagchi adds.

Keep reading: https://iisc.ac.in/events/livestock-grazing-influences-insect-populations-in-the-himalayas/

Read the Ecological Applications paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.3091