Residence and site fidelity of Sotalia guianensis in the Caravelas River Estuary, eastern Brazil
Rossi-Santos, M.R.; Wedekin, L.L.; Monteiro-Filho, E.L.A. (2007). Residence and site fidelity of Sotalia guianensis in the Caravelas River Estuary, eastern Brazil. J. Mar. Biol. Ass. U.K. 87(1): 207-212. https://dx.doi.org/10.1017/S0025315407055683
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154; e-ISSN 1469-7769, more
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| Authors | | Top |
- Rossi-Santos, M.R.
- Wedekin, L.L.
- Monteiro-Filho, E.L.A.
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| Abstract |
Between April 2002 and April 2005, 210 estuarine dolphin groups were sighted, with 58 animals individually identified. Fifteen dolphins were photo-identified just once, while only two animals were sighted in 15 different months. Some individuals showed long-term residence (more than 3 y). Residence rates showed heterogeneity in the dolphin's permanence of the estuary, with 60% of the individuals with low numbers (<10) and only 7% showing high values for residence (maximum=45.9). Continued resightings of some dolphins support the regular use of the study area by the animals, despite some individuals that, after a long time without resightings were registered again. Individual range analysis showed that dolphins shared the same common area, the Caravelas River Estuary. A marked fluctuation in the number of photo-identified dolphins was observed in the study area, revealed by the high number of individuals with just a few resightings. The majority of the dolphins (60%) present a yearly residence pattern, as observed in other areas, suggesting that a few individuals show high fidelity for the area, while many other dolphins move constantly between different areas for unknown reasons. |
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