Diet of Parrots in an Urban Area of São Paulo, Southeast Brazil

Although some species of parrots have adapted to urbanised environments, studies on this subject remain scarce. This study aimed to quantify the diet of parrots within an urban area of São Paulo city, Brazil, encompassing trophic niche breadth and dietary overlap. Observations were conducted on the University of São Paulo campus along a 6-km transect over three years (June 2022-May 2025), totalling 933.4 h of observation. Feeding events were documented exclusively via photography, ensuring accuracy in the identification of the involved species and their interactions. A total of 2929 feeding events were recorded, involving six parrot species and 83 food items, of which 79 were plant species - predominantly trees (74). Brotogeris tirica, Diopsittaca nobilis, and Amazona aestiva accounted for 97% of the events. Trophic niche breadths were low for the species with the highest number of records, with a predominance of seeds, fruits, and nectar from few plant species. Dietary overlap was low, except for both species of the genus Brotogeris. The parrots exploit a wide variety of food resources from both native and exotic plants. However, 59.5% of the consumed plant species were native, corresponding to 67.7% of the feeding events, suggesting the relevance of regional species in urban greening schemes. The utilisation of exotic plants suggests parrot adaptive plasticity. The seasonal exploitation of flowers during dry periods suggests behavioural flexibility in response to temporal resource availability. This study contributes to the understanding of parrot feeding ecology in cities and provides a foundation for urban green space planning.