Influence of sex and home range on released Antillean manatees’ behavior in Brazil

Abstract

The Antillean manatee is a threatened aquatic mammal subspecies which inhabits the northern and northeastern Brazilian coasts and estuarine areas. In this study we analyzed behavior data from rehabilitated and released manatees, to evaluate if sex and home range affect behavior richness and activity budget. Behavioral data from 29 manatees (15 females and 14 males) of northeastern Brazil was analyzed from 2006 to 2018. The animals were monitored by trained staff, who followed the animals using satellite and VHF telemetry systems. Six behavior states and 17 behavior events were recorded. The data was analyzed using GLM, ANOVA, and regression statistical tests. Behavior richness varied from three to 14 and activity budget indicated that individuals spent more time engaged in behaviors such as moving slowly and feeding in the bottom of the water body, but neither behavior richness nor activity budget were affected by sex. Behavior richness related to home range varied from five to 14 behaviors. Behavior richness and the activity budget for two social behaviors events - touch and interaction with wild manatees - were positively influenced by home range size, highlighting the importance of the use of space on behavior expression in manatees.