[MARMAM] New publication: Reproductive parameters and factors influencing calf survival of bottlenose dolphins that engage in a unique foraging cooperation with fishermen (Carolina Bezamat)

Carolina Bezamat de Abreu carolinabezamat at gmail.com
Mon Feb 10 11:23:58 PST 2020

Dear Members,

On behalf of my co-authors, I am pleased to share our recent publication:

Bezamat C, Castilho PV, Simões-Lopes PC, Ingram SN, Daura-Jorge FG (2020)
Reproductive parameters and factors influencing calf survival of bottlenose
dolphins that engage in a unique foraging cooperation with fishermen.
Marine Biology 167:5. doi: 10.1007/s00227-019-3611-4

A subset of the bottlenose dolphin *Tursiops truncatus gephyreus*
population in Laguna, southern Brazil, specialize in foraging cooperatively
with fishermen. In this study, we describe reproductive parameters for
these dolphins and investigate whether this specialized tactic generates
reproductive advantages for females that frequently engage in this unusual
behavior. We analyzed photo-identification data collected during 233
boat-based surveys during 2007–2009 and 2013–2017. From 27,808 high-quality
photographs, we identified and tracked the fate of 24 reproductive females
and 45 of their calves. Calving was found to be seasonal, with most births
occurring in late spring/summer. The average crude birth rate was 0.09, and
estimated fecundity was 0.17. The mean inter-birth interval was 2.09 (for
all calves) or 2.43 years (for surviving calves only). Survival to 1 and 2
years estimated by the Kaplan–Meier method was 0.78 (95% CI 0.65–0.92) and
0.65 (95% CI 0.51–0.83), respectively—which represents a survival rate in
the second year of 0.83. We investigated the potential influence of birth
timing, resource availability, and maternal foraging tactic, home range
size and frequency of interaction with fishermen on calf survival. Timing
of birth was a significant predictor of calf survival. Giving birth close
to the local mullet season would provide lactating females with increased
seasonal prey resources, leading to increased calf survival. Due to our
sample size (n = 9 cooperative and 15 non-cooperative females), we could
not conclude whether or not the cooperative foraging tactic influences calf
survival and female reproductive success. We emphasize the importance of
long-term monitoring of populations to understand regional life history
characteristics and provide accurate information for viability analyses.

The paper can be accessed using the following link:

If you have any questions, or would like me to send you a PDF copy of the
paper, please do not hesitate to contact me (carolinabezamat at gmail.com).

Best regards,

Carolina Bezamat
Universidade Federal de Santa Catarina, Brazil
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