Investigating Foraging Behaviour Patterns of Porphyrio poliocephalus (Grey-Headed Swamphen)

Abstract

The Grey-headed Swamphen, Porphyrio poliocephalus is a species of the recently reclassified “Supertramp” superspecies, Porphyrio. It has been observed that the foraging behaviours of Grey- headed Swamphens are affected by behavioural responses to unrelated stimuli, the specifics of which have not been studied after its reclassification as a species in 2015. This study qualitatively investigates the energetic profitability of foraging behaviours, as well as the effects of unrelated behavioural responses on the foraging behaviours of Grey-headed Swamphens. Observations were made at a site within the Talangama wetland, in the Western Province of Sri Lanka. Observations were made through focal sampling and scan sampling, utilizing videography captured from a significant distance to avoid the Hawthorne effect. It was concluded that their foraging patterns were primarily influenced by the type and abundance of food, as well as food preference. Surprisingly, rainy weather had only a minimal impact on their foraging frequency, as they seemed adapted to forage efficiently even during rain. Morning and evening foraging behaviours did not significantly differ, but during the breeding season, adult swamphens displayed increased territoriality and vigilance due to the presence of young ones. However, their choice of nesting sites suggested an effort to optimize foraging even during breeding seasons. When faced with predators, the swamphens typically engaged in laboured flight or running with open wings and avoided the area for some time. They also exhibited social relationships with White Breasted Waterhens while foraging, even during breeding seasons. In summary, these factors collectively contribute to optimizing the swamphens' foraging behaviours and help them achieve a net positive energy gain.

Keywords: Grey-headed swamphen, Foraging behaviour, Porphyrio poliocephalus