BEHAVIORAL RESPONSES OF FREE RANGING BOTTLENOSE
Transcrição
BEHAVIORAL RESPONSES OF FREE RANGING BOTTLENOSE
BEHAVIORAL RESPONSES OF FREE RANGING BOTTLENOSE DOLPHINS, Tursiops truncatus, TO BIOPSY SAMPLING IN SOUTHERN BRAZIL. Fruet, Pedro F. 1,3 , Dalla Rosa, L. 1,2 & Freitas, T.R.O 3 1 - Laboratório de Mamíferos Marinhos, Museu Oceanográfico de Rio Grande, RS, Brazil. 2 - Marine Mammal Research Unit, University of British Columbia, Canada. 3 – Departamento de Genética, Universidade Federal do Rio Grande do Sul, RS, Brazil [email protected] In this work we present a preliminary analysis on the reactions of bottlenose dolphin to biopsy sampling in the Patos Lagoon estuary, southern Brazil. Biopsying was conducted from a motorboat, using a crossbow and darts. To evaluate behavioral responses, we collected data on behavior (traveling, feeding, socializing and resting) and group size before each attempt. We defined four reaction categories: no reaction, low-level reaction (slight change in behavior, for a few seconds), moderate (more forceful reaction, like a tail slap, but not prolonged) and strong reaction (dolphins modified its behavior in a forceful and prolonged manner). Seventy-six attempts were made during 2003-2004. Fifty-seven attempts were miss and nineteen hit the dolphins. No strong reactions were observed in the present study. Low-level reactions were the most observed response in both hits or misses, representing 68.42% and 63.15%, respectively. Moderate reactions were observed in 26.3% (n=5) of the hits and 10.5% (n=6) of the misses, while 26.3% (n=15) and 5.2% (n=1) represented no reaction to misses and hits, respectively. Prior behavior state seems to be related with the dolphins reactions, as feeding behavior represented 72.7% of the moderate reactions, followed by 27.3% of socializing. We did not observe moderate reaction in dolphins that were traveling, just low-level reaction in the hits (n=5) and no reaction (n=5) and low-level reaction (n=8) to misses. The type of reaction and prior behavior to biopsying attempts (independent of hit or miss) was significantly different (G=7.94, P=0,01). When we tested group size versus behavior reaction, there was no significant difference (G=6.60, P=0,16). These results show that biopsy sampling of bottlenose dolphins at the Patos Lagoon estuary may be conducted without long lasting behavioral changes to the dolphins.
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