Comportamento do peixe-boi (Trichechus manatus manatus) nos oceanÃrios de ItamaracÃ: manejo e condiÃÃes abiÃticas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The aim of this study was to observe and describe the behavior of marine manatees, kept in captivity for rehabilitation and further release on their natural environment. To define the behavior pattern of these animals, their affiliate courtship activities and agonistic conducts were observed, verifying the presence of associations among group members, during the containment, besides possible abiotic influences. Due to the fact that the marine manatee is the most threatened aquatic mammal in Brazil, ethological studies, which contribute to future conservation, are fundamental to avoid extinction. Therefore, seven animals (two females and five males) were observed in captivity, at the National Center for Research, Conservation and Management of Aquatic Mammals, Aquatic Mammals Center/Ibama (CMA/ Ibama), ItamaracÃ, Pernambuco, Brazil. The qualitative and quantitative behaviors were registered, using âAd libitumâ, permitting the preparation of an ethogram. The method âall occurrencesâ were also used to evaluate the intraspecific interactions, from December 2006 to March 2007, totalizing 240 hours of monitoring. The manatees performed 60.88% of the behaviors in an individual manner, of which essential ones were developed, such as resting locomotion, feeding and drinking water. The similary way, the habit of ingesting feces was registered (coprophagy) and also some patterns that reveal captivity stereotype, such as hitting the head against the wall and spinning in circles inside the pool. Also, the animals presented low aggressive levels and associations that could be considered in the moment of the animalsâ release in their natural environment. These aggregations made by group individuals were not necessarily targeted at the opposite sex. The social categories were prevailing in the males which presented higher agonistic (75.9%) and affiliative (50.3%) categories and were responsible for a higher frequency of courtship behavior (62.5%). The females presented a higher frequency the captivity stereotype (65.5%) and shyness in social behaviors. On the interspecific interactions between manatees and humans, the animals remained indifferent in 78% of the total encounters, being observed that they are not disturbed by human activities. The abiotic factors did not exibit significant differences during the study period, except for the temperature, although the Spearman correlation has not shown any significant association between such abiotic factor and the animalsâ behavior. In summary, during the management of individuals, a series of criteria must be considered when selecting which animal is able to be released, and the affinity between animals and the low habituation must also be evaluated. Therefore ethological studies in captivity, focusing the associations, may contribute to a higher release success, due to the fact that animals of opposite sex, able to be released and with high affinity could help on the population increment of the species. It is important to consider that the habituation presented by the animals whit the humans presence may make them vulnerable in their natural environment, since they can become docile and then domesticated

ASSUNTO(S)

peixe-boi trichechus manatus manatus oceanÃrios comportamento pernambuco oceanografia biologica

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