Progesterone levels and reproductive status of white whales (De/phinapterus leucas) from the Canadian Arctic

Abstract

Serum progesterone levels were compared to the presence and size of ovaries, corpora lutea and fetuses in white whales sampled at three sites in the eastern Canadian Arctic. Generally, a progesterone level greater than 3.00 ng/ml indicated a pregnancy although there was some overlap in the range of values with mature, nonpregnant whales. This overlap may be an artifact of sample management or may indicate failed or failing pregnancies. Data are not available to test these hypothesis. Progesterone concentration was not significantly correlated with ovarian mass, corpus luteum mass or fetus mass. Ovaries of immature whales were significantly smaller than those of mature-but-notpregnant and pregnant whales.