Presentation Title
Female Productivity and Calf Survivorship of Bottlenose Dolphins (Tursiops truncatus) in Bocas, Panama
Abstract
The resident bottlenose dolphins of the Archipelago of Bocas del Toro are regularly exposed to intense interactions with dolphin-watching boats. Despite these intense interactions the dolphins remain in the area for two reasons: the bay’s safety from predators and its abundance in food resources. However, ongoing studies indicate that while the preferred food source, sardines, is abundant, they provide low caloric gain. This means that the dolphins must eat regularly. Previous research has shown that Bocas dolphin foraging behavior is disrupted throughout the day by tour boats. This has created concerns about the health of the population, particularly lactating mothers and the potential effects on calf survival. In this study we used mark-recapture data from 2004 to 2014 to infer dolphin female reproductivity and calf mortality rates. A total of 35 females were identified from 140 dolphins in the current catalogue. 23 of the 35 females have Dolphin Bay as a key part of their home range where they regularly interact with dolphin watching boats. Each female in this population had between one and three calves during the study period, with an average calving cycle of 62 months (SD: 21.91 months, Range: 24-97 months), longer than many known populations. Furthermore, calf mortality was estimated to be 0.46 which is higher than other populations at risk. The survival rate for this population was 0.54. Understanding female reproductive success in this local population of dolphins may provide a quantifiable measure of health and individual fitness, which are essential to protect this population.
Primary Faculty Mentor Name
Laura May-Collado
Status
Undergraduate
Student College
College of Agriculture and Life Sciences
Program/Major
Biological Sciences, Integrated
Primary Research Category
Biological Sciences
Female Productivity and Calf Survivorship of Bottlenose Dolphins (Tursiops truncatus) in Bocas, Panama
The resident bottlenose dolphins of the Archipelago of Bocas del Toro are regularly exposed to intense interactions with dolphin-watching boats. Despite these intense interactions the dolphins remain in the area for two reasons: the bay’s safety from predators and its abundance in food resources. However, ongoing studies indicate that while the preferred food source, sardines, is abundant, they provide low caloric gain. This means that the dolphins must eat regularly. Previous research has shown that Bocas dolphin foraging behavior is disrupted throughout the day by tour boats. This has created concerns about the health of the population, particularly lactating mothers and the potential effects on calf survival. In this study we used mark-recapture data from 2004 to 2014 to infer dolphin female reproductivity and calf mortality rates. A total of 35 females were identified from 140 dolphins in the current catalogue. 23 of the 35 females have Dolphin Bay as a key part of their home range where they regularly interact with dolphin watching boats. Each female in this population had between one and three calves during the study period, with an average calving cycle of 62 months (SD: 21.91 months, Range: 24-97 months), longer than many known populations. Furthermore, calf mortality was estimated to be 0.46 which is higher than other populations at risk. The survival rate for this population was 0.54. Understanding female reproductive success in this local population of dolphins may provide a quantifiable measure of health and individual fitness, which are essential to protect this population.