Citizen Science for the Study of Birds in Distinct Biomes: Diet of the Rufous-Tailed Jacamar (Galbula ruficauda) (Aves, Galbulidae) in Brazil

Abstract

Data obtained by citizen scientists have been used by researchers to study the natural history of tropical birds in several countries. For example, this approach has been increasing the knowledge about their feeding ecology, as many photographs show birds holding prey with their foot and/or bill. Due to this, the diet of numerous bird species can be examined with citizen science data. The Rufous-tailed Jacamar (Galbula ruficauda) is a forest bird species widely distributed throughout the Neotropics, and its diet was scarcely quantified in a few localities. This study aimed to investigate the diet of the Rufous-tailed Jacamar in three Brazilian biomes: the Caatinga, the Cerrado and the Atlantic Forest. Searches for photographs with evidence of feeding activities were done in February 2021 in the WikiAves and eBird databases, the major citizen science projects regarding birds found in Brazil. For each selected record, the captured prey was tentatively identified to the taxonomic Order level, and the date of obtention was classified as part of dry or rainy periods. The chi-square test was used to compare the numbers of prey of distinct insect orders in different periods and biomes. A total of 283 feeding records were obtained by citizen scientists in the Caatinga (12%) and surrounding portions of the Cerrado (45%) and the Atlantic Forest (43%). Captured prey comprised seven insect orders, and 15% of them could not be identified. In the Cerrado, the most numerous prey in its diet were those of the orders Lepidoptera and Odonata, followed by Hymenoptera and Hemiptera, in both the dry and rainy periods. On the other hand, substantial seasonal variation was observed in the Atlantic Forest. Records with Lepidoptera were more numerous than those with other insects in the dry period, while Hymenoptera had more records than other orders in the rainy period. In the Caatinga, prey with more records were those of the orders Odonata, Lepidoptera and Hymenoptera. This study suggests that photographic records available in citizen science databases, such as WikiAves and eBird, can be used to improve our knowledge about the diet of birds found in the Neotropics.