Diet of the Bobolink (Dolichonyx oryzivorus) in rice fields on its wintering grounds in Argentina

LORENZON, RODRIGO; ANTONIAZZI, CAROLINA; FABRE, FRANCO; QUIROGA, VIRGINIA ; REGNER, SILVIA; RONCHI VIRGOLINI, ANA LAURA; OLGUÍN, PAMELA; LEON, EVELINA; BELTZER, ADOLFO

ARARAJUBA: REVISTA BRASILEIRA DE ORNITOLOGIA

SOC BRASILEIRA ORNITOLOGIA

Lugar: Pelotas, RS; Año: 2019 vol. 27 p. 10 - 16

0103-5657

Winter diet of Bobolinks (Dolichonyx oryzivorus), a bird considered a pest of rice fields, is known to consist primarilyof seeds. However, it is not yet possible to establish the extent to which non-rice plants and animal components contribute to its diet.To contribute to these issues, we studied the diet of the Bobolink found in rice fields on its wintering grounds in Santa Fe, Argentina,to provide information on (i) the composition of the diet and (ii) the relative importance of plant and animal components in the dietand of the different prey categories. We captured Bobolinks with mist nets and obtained samples of stomach contents by warm waterand emetic-based regurgitation to determine the composition of the diet (n = 46 samples) and the importance of the different prey(n = 25 samples), mainly during March, just prior to northbound migration. We confirmed that the Bobolink´s diet in this regionduring this period is predominantly herbivorous (97%) and rice-based (55%), although it also consumes a large number of seeds ofnon-cultivated plants that represented 42% of the diet. Invertebrates, although of less importance than plant components (3%), hadbeen consumed by 97% of captured individuals. Our results document the importance of non-cultivated plants and animal prey inthe diet of Bobolinks in addition to rice.