title: Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana).
abstract: Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland, 8127 Regents Dr., College Park, MD 20742, USA; Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Brown
authors.affiliation: U.S. Geological Survey, Patuxent Wildlife Research Center, 12100 Beech Forest Road, Laurel, MD 20708, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Converse
authors.affiliation: U.S. Geological Survey, Patuxent Wildlife Research Center, 12100 Beech Forest Road, Laurel, MD 20708, USA.
authors.forename: Jane N
authors.initials: JN
authors.lastname: Chandler
authors.affiliation: U.S. Geological Survey, Patuxent Wildlife Research Center, 12100 Beech Forest Road, Laurel, MD 20708, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Shafer
authors.affiliation: Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA.
authors.forename: Janine L
authors.initials: JL
authors.lastname: Brown
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland, 8127 Regents Dr., College Park, MD 20742, USA.
authors.forename: Carol L
authors.initials: CL
authors.lastname: Keefer
authors.affiliation: Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA. Electronic address: songsasenn@si.edu.
authors.forename: Nucharin
authors.initials: N
authors.lastname: Songsasen
mesh_terms: D000818:Animals; D001717:Birds; D001947:Breeding; D005260:Female; D042341:Gonadal Hormones; D043762:Reproductive Behavior
chemical_list: D042341:Gonadal Hormones
keywords: Behavior; Egg laying; Endocrinology; Glucocorticoids; Reproduction; Whooping crane