Foraging habits in a generalist predator: Sex and age influence habitat selection and resource use among bottlenose dolphins (Tursiops truncatus). Issue 1 (30th May 2014)

• Record Type: Journal Article
• Authors: Rossman, Sam; Berens McCabe, Elizabeth; Barros, Nélio B.; Gandhi, Hasand; Ostrom, Peggy H.; Stricker, Craig A.; Wells, Randall S.
• Is Part Of: Marine mammal science. Volume 31:Issue 1(2015)
• Page Start: 155
• Page End: 168
• Publication Date: 2014-05-30
• Subjects: Marine mammals -- Congresses; Marine mammals -- Periodicals; Marine mammals, Fossil -- Periodicals; Mammifères marins -- Périodiques; 599.5
• DOI: 10.1111/mms.12143
• Languages: English
• ISSNs: 0824-0469

Abstract

<abstract abstract-type="main" id="mms12143-abs-0001"> <title>Abstract</title> <p>This study examines resource use (diet, habitat use, and trophic level) within and among demographic groups (males, females, and juveniles) of bottlenose dolphins (<italic>Tursiops truncatus</italic>). We analyzed the δ¹³C and δ¹⁵N values of 15 prey species constituting 84% of the species found in stomach contents. We used these data to establish a trophic enrichment factor (TEF) to inform dietary analysis using a Bayesian isotope mixing model. We document a TEF of 0‰ and 2.0‰ for δ¹³C and δ¹⁵N, respectively. The dietary results showed that all demographic groups relied heavily on low trophic level seagrass‐associated prey. Bayesian standard ellipse areas (SEA_b) were calculated to assess diversity in resource use. The SEA_b of females was nearly four times larger than that of males indicating varied resource use, likely a consequence of small home ranges and habitat specialization. Juveniles possessed an intermediate SEA_b, generally feeding at a lower trophic level compared to females, potentially an effect of natal philopatry and immature foraging skills. The small SEA_b of males reflects a high degree of specialization on seagrass associated prey. Patterns in resource use by the demographic groups are likely linked to differences in the relative importance of social and ecological factors.</p> </abstract>