Foraging strategies of three co-occurring ibis species (Black-headed, Glossy and Red-naped) in a semi-arid landscape of western India

It has been considered that the coexistence of similar species is facilitated by the differentiation in their foraging habits. We sought to test this hypothesis by evaluating the foraging behavior and factors influencing the foraging success of three coexisting ibis species – Black-headed ibis ( Threskiornis melanocephalus), Red-naped ibis ( Pseudibis papillosa), and Glossy ibis ( Plegadis falcinellus) – in the semi-arid landscape of western India from January 2020 to April 2022. Overall, foraging parameters were similar among the species, except for inter-individual parameters (P < 0.05) and for the number of locomotion turns each species performed. Probing and the number of nearby wading birds significantly and positively influenced the foraging success of all the Ibis species studied. Seasonal variations affected the foraging success only for the Red-naped Ibis and within a season, the foraging success was significantly different between species. All species showed different water depth utilization for foraging. Red-naped Ibis used habitats other than wetlands without impacting its foraging success. Also, the foraging success differed between adults and juveniles of the Red-naped ibis but remained consistent for the Black-headed ibis. These findings can aid the future development of hypotheses related to how similar species coexist and help in management and conservation efforts for these species.