Widespread Occurrence of Foot Trembling Behaviour Among Wintering Shorebirds in a Degraded Coastal Ecosystem

Abstract

This study examines foot trembling behaviour in shorebirds at an important wintering ground along the west coast of India, challenging the traditional notion that this behaviour is limited to visual foragers. The research was carried out in two primary habitats within the Kadalundi-Vallikkunnu Community Reserve: mudflats and mangroves. The investigation focused on seven migratory shorebird species, including visual foragers (Tibetan Sand Plover, Greater Sand Plover, and Pacific Golden Plover), tactile foragers (Sanderling and Terek Sandpiper), and opportunistic foragers (Common Redshank and Common Greenshank). Shorebird monitoring was conducted during low tide using direct visual counts and video recording. The findings demonstrate that foot trembling is prevalent across all species studied, regardless of their foraging strategy, and is closely linked to habitat conditions affecting prey availability. Moreover, the study indicates that tactile foragers are particularly reliant on foot trembling, suggesting significant habitat degradation that impacts prey availability for species with specialized evolutionary adaptations.