Comparações etárias quanto ao tempo de apneia e uso de estratégias de forrageio, e alterações comportamentais em golfinhos sotalia fluviatilis (gervais, 1853) provocadas por embarcações de turismo

Abstract

The inlet of dolphins is situated in Pipa, in the south Coastal of Rio Grande do Norte State (6°13’36,7”W e 35°3’36,7”S). It was divided in six imaginary squares that went possible to map de animal displacement. Also it had been registered the age bands, the submersion time, behavior, direction in which the animal went up to the ; surface and in occasions in with embarkations was approaching, we estimate the distance between both and measure the submerse time and the cohesion behavior.We observe the submersion time is directly proportional to corporal mass and behavior. During rest, we found the highest means. We could verify the use of standards of displacement in the bay before the start of the pursuits. These standards had been compared between juveniles and adults, and associates with three tactics of foragíng: ambush, search for in a restricted area and search for in a broad area. Since, after the first attack, adults immediately initiate a new pursue less frequently than juveniles, used a bigger area to attack its prey and that the capacity of remain submerse is proportional to the corporal size, we consider that the adults are more effícient hunters. We found that the ambush tactic is the more effícient but it is not the more used probably because of the prey distribution form in the environment. The differences in the proportion of use of the others tactics between adults and juveniles it is probably limited by aerobic capacities. Adults delayed more to recuperate the breath mean, because showed the same recuperate pattem ofjuveniles and had a respiratory frequency lower than juveniles. The direction of the body of the animais during the ascents to the surface ‘ showed specific standards in some behaviors. The majority of the attacks it was happened in the south direction, the subsequent ascents in the north direction and during the others activities, the animal remained positioned preferential in the , positions of north until least. We relate this to the fact that this locality indicates where in the inlet there would be more prey. Regarding the approach of the boats to the animais, we verify that there were a tendency in animais stays more time submerse and staying in a cohesion form.