title: The physiology of cooperative breeding in a rare social canid; sex, suppression and pseudopregnancy in female Ethiopian wolves.
abstract: Ethiopian wolves, Canis simensis, differ from other cooperatively breeding canids in that they combine intense sociality with solitary foraging, making them a suitable species in which to study the physiology of cooperative breeding. The reproductive physiology of twenty wild female Ethiopian wolves (eleven dominant and nine subordinate) in Ethiopia's Bale Mountains National Park was studied non-invasively through the extraction and assaying of estradiol, progesterone and glucocorticoids in collected fecal samples using enzyme and radioimmunoassays. All dominant females showed increased estradiol concentrations and/or mating behavior during the annual mating season. In contrast, none of the subordinate females showed increased estradiol concentrations or mating behavior during the mating season. However, two subordinate females came into estrus outside of the mating season. Both dominant and subordinate females had higher average progesterone concentrations during the dominant female's pregnancy than at other times of the year, and two subordinate females allosuckled the dominant female's pups. No statistically significant differences in glucocorticoid concentrations were found between dominant and subordinate females. These results suggest that subordinate females are reproductively suppressed during the annual mating season, but may ovulate outside of the mating season and become pseudopregnant. No evidence was found to suggest that reproductive suppression in subordinate females was regulated through aggressive behaviors, and no relationship was found between fecal glucocorticoids and dominance status.
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney OX13 5QL, UK; Ethiopian Wolf Conservation Programme, PO Box 215, Robe, Bale, Ethiopia; Institute for Breeding Rare and Endangered African Mammals (IBREAM), Mammal Research Institute, University of Pretoria, Lynnwood Road, Pretoria 0028, South Africa. Electronic address: freyavankesteren@gmail.com.
authors.forename: Freya
authors.initials: F
authors.lastname: van Kesteren
authors.forename: Monique
authors.initials: M
authors.lastname: Paris
authors.forename: David W
authors.initials: DW
authors.lastname: Macdonald
authors.forename: Robert
authors.initials: R
authors.lastname: Millar
authors.forename: Kifle
authors.initials: K
authors.lastname: Argaw
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Johnson
authors.forename: Wenche
authors.initials: W
authors.lastname: Farstad
authors.forename: Claudio
authors.initials: C
authors.lastname: Sillero-Zubiri
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D003299:Cooperative Behavior; D004958:Estradiol / Q000032:analysis; D005243:Feces / Q000737:chemistry; D005260:Female; D005938:Glucocorticoids / Q000032:analysis; D011247:Pregnancy; D011374:Progesterone / Q000032:analysis; D011555:Pseudopregnancy; D012098:Reproduction / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D019596:Wolves / Q000502:physiology*
chemical_list: D005938:Glucocorticoids; D011374:Progesterone; D004958:Estradiol
keywords: Dominance rank; Estradiol; Ethiopian wolves; Glucocorticoids; Progesterone; Reproductive suppression