BREEDING BIOLOGY OF Vanellus chilensis (AVES: CHARADRIIDAE) IN A PERI-URBAN AREA OF SOUTHERN BRAZIL

Abstract

The neotropical species Vanellus chilensis, known as Southern Lapwing, is found in grassland environments, in rural and urban open areas. The species is considered a social Bird, which aggregates in pairs or small groups during the breeding period, in austral spring and summer. During the reproductive period, the cooperative breeding behavior is common among individuals of the species, when a non-breeding individual, called “helper”, assists the breeding pair in parental care activities. We monitored a total of 11 social breeding unities of V. chilensis between august 2014 and january 2015 in the Universidade do Vale do Rio dos Sinos campus, in São Leopoldo, Rio Grande do Sul. We conducted nest observations, by evaluating the breeding success of individuals regarding eggs and chick’s loss, with and without helpers’ presence, as well as behavioral aspects. We recorded the laying of 65 eggs, of which 10.7% achieved breeding success, regarding the number of viable chicks. In this study, helpers’ presence in the nests did not influence the breeding success of individuals, thus, dismissing the hypothesis that helpers’ assistance improves breeding success of the species. Our findings contribute to the knowledge on the breeding biology of V. chilensis in peri-urban areas.