Date of Completion

2021

Document Type

Honors College Thesis

Department

Biology

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

Dr. Laura J May-Collado

Second Advisor

Dr.Sara Helms Cahan

Third Advisor

Dr. Krista Jones

Keywords

Boat Compliance, Dolphin Watching, Tour Boats, Photo Identification, Reproductive Rate, Fecundity

Abstract

Inshore bottlenose dolphins (Tursiops truncatus) show high levels of site fidelity that have enabled the establishment of dolphin watching activities worldwide. Bottlenose dolphins in Bocas del Toro, Panama live in a small and genetically isolated population. Dolphins, whose home ranges are primarily found within Dolphin Bay, are exposed to high levels of harassment by tour boats. Previous research shows that Dolphin Bay is a stressful environment for these dolphins. During encounters with tour boats, dolphin foraging and social activities are interrupted, mother-calf pairs are separated, and dolphins are sometimes injured by these interactions. As a result, the International Whaling Commission has repeatedly expressed concerns about the impacts of tourism activities on this dolphin population. This Honors thesis studies the group behavior, female reproduction, and calf survivorship of bottlenose dolphins in the archipelago of Bocas del Toro, Panama from 2004 to 2019. In my first chapter, I introduce this population. In chapter 2, I review the population characteristics of bottlenose dolphins in Bocas del Toro and compare them to other well-known populations that experience similar levels of harassment by tour boats. In chapter 3, I describe bottlenose dolphin group composition and behavioral activities in the context of calves from behavior data. Finally in chapter 4, I calculate female dolphin reproduction productivity and calf survivorship rates using photo-identification data (photos of natural marks on the dorsal fins of dolphins). My results show that groups with calves were larger in habitats where there is more tour-boat activity and when dolphins were engaged in social activities. Females in Bocas del Toro had a mean interbirth interval (IBI) of 54.96 months and a calf survivorship rate of 41.3%. Together, my results suggest a potential impact of tour-boat interactions, directly and indirectly, on the health of this dolphin population. The results will inform ongoing efforts by the government to protect these dolphins’ critical habitat which will lead to stronger regulations on boat activity.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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