TY - JOUR
T1 - Sex steroid hormones and behavior reveal seasonal reproduction in a resident fin whale population
AU - Carone, Erica
AU - Pardo, Mario A.
AU - Atkinson, Shannon
AU - Mashburn, Kendall
AU - Pérez-Puig, Héctor
AU - Enríquez-Paredes, Luis
AU - Gendron, Diane
N1 - Publisher Copyright:
© 2019 The Author(s). Published by Oxford University Press and the Society for Experimental Biology.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Fin whales in the Gulf of California constitute a resident population genetically isolated from the rest of the North Pacific Ocean. Its small population size and the scarce information available about its dynamics in a semi-enclosed sea underline the importance of conducting studies about its reproduction. Given the monsoonal regime that dominates the oceanographic habitat of this region, we hypothesized seasonality in the population's reproductive activity. To test this, we validated and assayed testosterone and progesterone from blubber biopsies of free-ranging individuals. Lactating females exhibited low progesterone concentrations, whereas a group of females of unknown reproductive stage, but with extremely high progesterone concentrations, showed strong evidence of separation and were considered to be likely ovulating or pregnant. A seasonal model of testosterone concentrations showed a high peak during the late summer. This trend was supported by the first documentation of courtship events and by the recording of a female with high progesterone concentration during summer and re-sighted with a calf 1 year later. Therefore, the breeding in this resident population would be seasonal, as it is in migratory baleen whales, but occurring during the summer/autumn, which is the least productive season in the Gulf of California. Our study represents an important input to assist in future management policies of this protected population.
AB - Fin whales in the Gulf of California constitute a resident population genetically isolated from the rest of the North Pacific Ocean. Its small population size and the scarce information available about its dynamics in a semi-enclosed sea underline the importance of conducting studies about its reproduction. Given the monsoonal regime that dominates the oceanographic habitat of this region, we hypothesized seasonality in the population's reproductive activity. To test this, we validated and assayed testosterone and progesterone from blubber biopsies of free-ranging individuals. Lactating females exhibited low progesterone concentrations, whereas a group of females of unknown reproductive stage, but with extremely high progesterone concentrations, showed strong evidence of separation and were considered to be likely ovulating or pregnant. A seasonal model of testosterone concentrations showed a high peak during the late summer. This trend was supported by the first documentation of courtship events and by the recording of a female with high progesterone concentration during summer and re-sighted with a calf 1 year later. Therefore, the breeding in this resident population would be seasonal, as it is in migratory baleen whales, but occurring during the summer/autumn, which is the least productive season in the Gulf of California. Our study represents an important input to assist in future management policies of this protected population.
KW - Blubber
KW - fin whale
KW - progesterone
KW - seasonal reproduction
KW - testosterone
UR - http://www.scopus.com/inward/record.url?scp=85083771028&partnerID=8YFLogxK
U2 - 10.1093/conphys/coz059
DO - 10.1093/conphys/coz059
M3 - Artículo
C2 - 31687140
AN - SCOPUS:85083771028
SN - 2051-1434
VL - 7
JO - Conservation Physiology
JF - Conservation Physiology
IS - 1
M1 - coz059
ER -