Mystic Aquarium & Institute for Exploration

Beluga whales live in an extreme environment, moving from deep water areas with heavy ice cover in the winter to shallow, relatively ice free estuaries in the summer.  Reproductive events coincide with these migrations; breeding occurs in the spring and calving occurs 15 months later in the following summer.  While this seasonal pattern of reproduction is well documented, very little information exists regarding male seasonality.

In this study, we hope to determine if male belugas undergo physiological changes that correlate with the observed reproductive seasonality in this species.  Several male belugas in the US and Canada have been trained to voluntarily participate in this project.  Twice a month, ultrasounds are performed to measure testes size.  Blood samples are also collected, and we hope to relate any seasonal changes in testes size to seasonal variation in testosterone levels in the blood.  This information will benefit the beluga breeding cooperative in zoological facilities and improve our understanding of beluga reproduction.