Seasonal variations in spatial usage by the estuarine dolphin, Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) at its southern limit of distribution.
Braz J Biol
; 67(1): 1-8, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17505744
The use of space by the resident population of estuarine dolphins (Sotalia guianensis) in Norte Bay, southern Brazil was studied by boat surveys between 2000 and 2003. Data such as the geographical position and group size was collected at 5-minute intervals using focal-group sampling. The distribution and seasonal and daily group home-ranges were estimated using a GIS (Geographic Information System) environment. The dolphins did not use the area homogeneously, restricting their activities to a well-defined area located in the western part of the bay, while the use of the eastern part was not observed. A discrepancy between the Environment Protection Area of Anhatomirim, created especially to protect this population and the distribution of the dolphins was observed. Seasonal group home-range varied both qualitatively and quantitatively among the four consecutive seasons analyzed. The dolphins tended to use a larger area in cold seasons, when apparently the abundance of major prey items is lower. Core areas of intense use were identified, and also varied seasonally. These core areas may be regarded as critical habitats and require special legislation and control. The mean daily group home-range did not differ statistically among seasons. The present study corroborates a spatially strict residency pattern of the estuarine dolphin in highly productive coastal ecosystems.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estações do Ano
/
Golfinhos
Tipo de estudo:
Qualitative_research
Limite:
Animals
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Braz J Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil