Ecology and conservation status of tucuxi (<i>Sotalia fluviatilis</i>) in the Pacaya-Samiria Reserve, Peru
DOI:
https://doi.org/10.5597/lajam00158Abstract
The distribution, relative abundance, group size, reproductive seasonality, and conservation status of tucuxi (Sotalia fluviatilis) were investigated in Peru’s Pacaya-Samiria National Reserve from 1996 to 2000. Data collection consisted of boat-based surveys of dolphins and habitat, necropsies, photo-identification of individual dolphins, and interviews with local people. Mean encounter rates were between 0.01-0.80 tucuxi/km in rivers, and 0.05-2.17 tucuxi/km2 in lakes, and were within the ranges reported for riverine tucuxi throughout their distribution. Encounter rates were highest in confluences, intermediate in lakes, and lowest in rivers. Encounter rates increased with river width. Most tucuxis were seen within 100m from shore in large rivers, and large groups were associated with confluence areas and mid-channel islands. Within lakes, tucuxis were associated with areas of deeper water. Tucuxis were not found in waters <3m depth in rivers, or <1.8m depth in lakes. Seasonal differences in encounter rates did not exist in lakes and rivers. In confluences tucuxis occurred in highest densities during low water, and lowest densities during high water. Diurnal patterns of occurrence were not observed. Tucuxis were seen most often as singles or pairs, although groups as large as 13 were observed. Significant seasonal differences in group size were not detected. Neonate tucuxi were observed in all seasons, with a slight peak in encounter rates during high water. Abundance estimates were affected by survey methods, and strengths and weaknesses of various methods are discussed. Photo-identification rates were low, and this method did not yield information about tucuxi site fidelity, movement patterns, social structure, or population size. Local people in the Reserve did not seem to have the same myths and general apprehension about tucuxis as for the other sympatric dolphin, Inia. There was no evidence that tucuxi were poisoned by fishermen, unlike Inia. Potential threats to tucuxi in this region were entanglement in fishing gear, mercury in migratory fish from gold mining elsewhere, oil spills, ship strikes, and disturbance from boats. Only one dead tucuxi was encountered, and had been entangled in a turtle net. Tucuxi teeth were found for sale in local markets.Downloads
How to Cite
McGuire, T. L. (2010). Ecology and conservation status of tucuxi (<i>Sotalia fluviatilis</i>) in the Pacaya-Samiria Reserve, Peru. Latin American Journal of Aquatic Mammals, 8(1-2), 103-110. https://doi.org/10.5597/lajam00158
Issue
Section
Articles
License
Authors who publish with this journal agree to the following terms:- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).