Dear colleagues:
The following manuscript (with abstract attached) was recently published. PDf requests with Julia Oshima ([email protected]).
Oshima, J. E. F.; Santos, M.C. de O. ; Bazzalo, M. ; Flores, P. A. C. ; Pupim, F.N. 2010. Home ranges of Guiana dolphins (Sotalia guianensis) (Cetacea: Delphinidae) in the Cananéia estuary, Brazil. Journal of the Marine Biological Association of the United Kingdom (Print), v. 90, p. 1641-1647.
Home ranges of seven Guiana dolphins (Sotalia guianensis) (Van Beneden, 1864) were studied in the Cananeia estuary (25°03′S 47°55′W), south-eastern Brazil. Boat-based observations were conducted from May 2000 to July 2003 in 132 km2 of protected inner waters. The photo-identification technique was used to follow naturally marked individuals through time and space. From a total of 138 catalogued individuals, five males and two females presented 20+ sightings and were used for home range estimation. Sightings were plotted and analysed in a Geographic Information System (GIS). With the ‘Home Range Tools’ extension the fixed kernel density estimator with band width (smoothing parameter) chosen via least squares cross-validation was performed for each individual. The fixed kernel method wa s used to estimate the non-parametric utility distribution of each dolphin, keeping band width (h) constant for a data set. The first polygons created by these parameters had an amoeboid shape and in some cases more than one centre of activity. The 95% home range estimated outlines varied from 1.6 to 22.9 km2 (7.9 +8.3 km2). This large interval shows strong evidences on individual variation in S. guianensis’ home ranges. Several individuals showed small home ranges when compared to other cetacean species. An overlap of home ranges of different sizes and shapes were observed for Guiana dolphins with large range movements. Centres of activity were concentrated in the main entrance of the Cananeia estuary. This was a first attempt to understand the way S. guianensis uses the Cananeia estuary and such data are essential for conservation and management purposes.Best regards,
Julia Emi de Faria Oshima
Departamento de Zoologia, Instituto de Biociências,
Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Campus Rio Claro
Av 24-A, 1515, Bela Vista, Rio Claro, SP, Brasil, 13506-900.
Telefone/Phone: 55-19-35578115
Fax: 55-19-3526-4300
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