title: Evidence that bears are induced ovulators.
abstract: 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.
authors.affiliation: Reproductive Endocrinology & Infertility, Greenville Hospital System, 890 W Faris Road, Suite 470, Greenville, SC 29605, USA. bboone@ghs.org
authors.forename: William R
authors.initials: WR
authors.lastname: Boone
authors.forename: Becky B
authors.initials: BB
authors.lastname: Keck
authors.forename: Jeffery C
authors.initials: JC
authors.lastname: Catlin
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Casey
authors.forename: Edna T
authors.initials: ET
authors.lastname: Boone
authors.forename: Penny S
authors.initials: PS
authors.lastname: Dye
authors.forename: Randy J
authors.initials: RJ
authors.lastname: Schuett
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsubota
authors.forename: Janice C
authors.initials: JC
authors.lastname: Bahr
mesh_terms: 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*
chemical_list: D011374:Progesterone