Spatial and temporal distribution of manatees (trichechus manatus) reintroduced in the northeastern coast of Brazil

Abstract

Many West Indian manatees (Trichechus manatus) that strand along the northeast Brazilian coast are calves, which are often rescued and carried to the Peixe-Boi Project rehabilitation facilities in Itamaracá, Pernambuco State where they are prepared to reintroduction. During the ten years period of October 1994 to December 2004, thirteen captive manatees were radio tagged, released and tracked in three main northeast coastal areas as part of the Brazilian Manatee Reintroduction Program. All individuals were monitored locally with VHF transmitters, during brief periods, four were also tracked remotely with satellite-monitored radio tags. Five manatees (39.5%) had long-term tracks over 14 months or 420 days (Total= 10166 days; Maximum=2663 days; Mean=2031 days; SD=1572 days) that met criteria for inclusion in analyses of spatial and seasonal movement patterns. Manatees were tracked from Praia do Forte, Bahia (12.538ºS/38.474ºW) to Macau, Rio Grande do Norte (5.084ºS/36.682ºW), covering around 1200 km and six states along the northeast coast. Three manatees occupied large home ranges, with each containing a few sites of high fidelity where they spent considerable time, while two used restrict home range having only one site with high fidelity. Others two manatees not showed movements along coast and occupied a restrict area like their fidelity site. Two manatees with short tracking histories showed visible weight loss soon after release and were re-captured after having moved long distances, including offshore movements into deep waters. The high rate of survival for released manatees, their adaptation to areas within the former range of wild manatees, and birth of a calf to a released captive manatee are indicators of the success of the Brazilian Manatee Reintroduction Program.