A methodology to obtain adults? blood samples in nests of the cattle egret, Bubulcus ibis (Ardeidae)

ELAINE DANTAS DE SOUZA; VERA LÚCIA CORTIÇO CÔRREA RODRIGUES; EMANUEL MORALEZ-SILVA; CAROLINA ISABEL MIÑO; SÍLVIA NASSIF DEL LAMA

Foz do Iguazú, PR,

Congreso; 58° Congreso brasileño de Genética; 2012

Sociedade Brasileira de Genetica

Obtaining DNA from offspring and parents is essential for better conducting parentage studies in natural populations. In some groups of birds, including egrets of the Ardeidae family, capturing adults at nests is not an easy task. On the other hand, handling nestlings at nest is relatively easy at the beginning of their developmental cycle. The present study aimed to apply a method, already tested in seabirds, to obtain samples of incubating adults of the cattle egret (Bubulcus ibis)using fake fiberglass eggs containing living and starving blood sucking insects. We distributed false eggs in 17 nests in a breeding colony located in Rio Claro city, São Paulo State, Brazil. False eggs mimicked natural dimensions and coloration of natural eggs and were placed inside nests together with natural clutches. The blood sucking insects were able to project their feeding apparatuses through holes made in the eggs. Holes in the eggs were not big enough to let insects escape. We tested the following hematophagous insects: Triatoma phyllosoma picturata, Triatoma pallidipennis, Panstrongylus megistus and Triatoma costalimai, obtained from Superintendência de Controle de Endemias (SUCEN). Sampling of adult blood was performed during the incubating period, about a week after egg-laying. As female and male cattle egrets switch turns when incubating eggs, false eggs were placed within nests 3-6 times along the day, at different hours, to increase the chance of sampling both adults. Eggs were removed from nests after having remained there for 20-30 min; insects were removed from eggs and about 0.10ul of blood were obtained from their abdomen using sterilized syringes. Blood samples from six of this 17 nests were sexed and genotyped at eight species-specific polymorphic microsatellite loci (Bi01, Bi15, Bi18, Bi20, Bi26, Bi28, Bi29 e Bi30). Molecular sexing confirmed that adults of both sexes were sampled. Analyses of genotypes showed that the obtained samples were useful for further parentage assignment studies