Evidence that bears are induced ovulators.
The objective of this study was to determine if black bears are induced ovulators. We conducted a single experiment with two replicates; each replicate was divided into two arms: females exposed to male bears and females without male exposure. We used laparoscopy to examine ovaries for corpora lutea and measured serum progesterone concentrations. Six of the seven isolated females failed to ovulate, while seven of the eight females exposed to males produced one to four corpora lutea. Furthermore, isolated females had significantly lower progesterone concentrations than females exposed to males. Thus, our data suggest that the American black bear is an induced ovulator. These results may aid biologists in their efforts to reproduce ursids in controlled environments.
Boone
William R
WR
Reproductive Endocrinology & Infertility, Greenville Hospital System, 890 W Faris Road, Suite 470, Greenville, SC 29605, USA. bboone@ghs.org
Keck
Becky B
BB
Catlin
Jeffery C
JC
Casey
Kevin J
KJ
Boone
Edna T
ET
Dye
Penny S
PS
Schuett
Randy J
RJ
Tsubota
Toshio
T
Bahr
Janice C
JC
D000818:Animals; D003338:Corpus Luteum; D005260:Female; D010535:Laparoscopy / Q000662:veterinary; D008297:Male; D010060:Ovulation / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D012726:Sexual Behavior, Animal; D001503:Ursidae / Q000502:physiology*
D011374:Progesterone