No abstract

Nature-based tourism is an important part of the global tourism industry, and its

No abstract

Intervals between sampling are a major concern in studies of behaviour. Objective choices compromise accurate definition, collection of enough data and avoidance of time dependence between samples. This paper tests whether significant differences occur in the proportion of activities of Sotalia guianensis when the protocols of observation using different intervals between registers are varied. The study was carried out at Formosa Bay, south coast of Rio Grande do Norte over a period of 40 days (251 hours). The results show that the use of different intervals of data registering result in non-significant differences in the quantification of behaviour. However, a tendency to over-estimate forage and under-estimate travel at 2 minutes relative to 8 minutes intervals was detected. This warns of the need to define a proper interval between behavioural sampling and addresses the question of the adoption of a common protocol for fast and continuous assessment of different estuarine dolphin populations throughout the Brazilian coast.

The coloration pattern of the estuarine dolphin, Sotalia guianensis, does not display variations in its distribution and the colour grey, as its common name suggests, is predominant. On the coast of the state of Rio Grande do Norte a dolphin was sighted with atypical coloration in relation to animals from that region. After observing its morphological characteristics, it was verified that the animal was a white specimen of S. guianensis. Although photographic recordings were made, the reddish coloration of the eye cannot be confirmed, a characteristic that would identify the animal as an albino dolphin. Despite not being very frequent, cases of coloration anomalies such as albinism have been previously recorded in 20 species of cetaceans. However, there have been no cases recorded for the estuarine dolphin.