No abstract

There is great difficulty in maintaining aquatic mammals in captivity, since the attempt to replicate the environment they live in poses an enormous challenge. Poor captivity facilities without environmental enrichment can lead to different consequences for animal health, including the appearance of stereotypical movements. The aim of this study was to identify these behaviours in three groups of animals, one group of manatees inhabiting a reintroduction oceanarium in Pernambuco (PE) state, and two other groups confined in corrals constructed in natural areas (estuaries), one located in Paraiba state and the other in Alagoas state, all in north-eastern Brazil. Observations were conducted using the focal animal sampling method. It was found that the animals inhabiting the reintroduction oceanarium with no environmental enrichment showed stereotypical behaviour such as ‘Back-and-forth’ movements, ‘Hitting head against the limiting structure’ and ‘Hitting the muzzle’, while animals constrained within estuaries did not. The ‘circle swimming’ behaviour was present in a higher percentage of the animals captive in the reintroduction oceanarium, although no significant difference between the sites was found. The number and frequency of occurrence of stereotypical behaviours was significantly higher in animals kept in the reintroduction oceanarium in PE than in those of other locations. Based on these results we recommend the use of appropriate environmental enrichment and the reduction of time manatees stay confined in the reintroduction oceanarium.

The aim of this work was to analyze whether there are differences between the development pattern of Antillean manatee (Trichechus manatus) calves born in captivity and those rescued and kept under rehabilitation. Biometrics data were collected from 1990 to 2010 from 38 calves, 29 of which still had the remnants of the umbilical cord and had been rescued from the Brazilian northeastern coastline (Group I), and nine individuals that were born in captivity and remained with their mothers (Group II). Among the measures obtained through biometry, the total length and weight of the animal were recorded. Given that the breastfeeding of calves occurs approximately until the age of 2 yr, data obtained until the 24th month of life of each individual were evaluated. An average increase in weight of 53.50 +/- 38.54 kg (mean +/- standard deviation [SD]) was detected in Group I and a gain of 106.87 +/- 47.21 kg (mean +/- SD) in Group II. From months 13 to 24, no significant difference in the weight increment was observed. A similar pattern occurred with regard to the increase in the overall length during the first year, where animals from Group I grew 34.81 +/- 17.94 cm (mean +/- SD) and from Group II grew 83.83 +/- 28.21 cm, a statistically significant difference. The growth was not significantly different from 13 to 24 mo. The results found in this study identified the need for a review of the nutritional diet offered to orphaned calves rescued and kept in captivity. The results also support the need for a better adequacy of facilities for these animals as a way to encourage the management strategies adopted for manatee calves maintained in captivity.