Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition

ABSTRACT Evaluating how management practices influence the population dynamics of ungulates may enhance future management of these species. For example, in mule deer (Odocoileus hemionus), changes in male/female ratio due to male‐biased harvest may alter rates of pregnancy, timing of parturition, an...

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Main Authors: Eric D. Freeman, Randy T. Larsen, Mark E. Peterson, Charles R. Anderson Jr., Kent R. Hersey, Brock R. Mcmillan
Format: Article
Language:English
Published: Wiley 2014-12-01
Series:Wildlife Society Bulletin
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Online Access:https://doi.org/10.1002/wsb.450
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author Eric D. Freeman
Randy T. Larsen
Mark E. Peterson
Charles R. Anderson Jr.
Kent R. Hersey
Brock R. Mcmillan
author_facet Eric D. Freeman
Randy T. Larsen
Mark E. Peterson
Charles R. Anderson Jr.
Kent R. Hersey
Brock R. Mcmillan
author_sort Eric D. Freeman
collection DOAJ
description ABSTRACT Evaluating how management practices influence the population dynamics of ungulates may enhance future management of these species. For example, in mule deer (Odocoileus hemionus), changes in male/female ratio due to male‐biased harvest may alter rates of pregnancy, timing of parturition, and synchrony of parturition if inadequate numbers of males are present to fertilize females during their first estrous cycle. If rates of pregnancy or parturition are influenced by decreased male/female ratios, recruitment may be reduced (e.g., fewer births, later parturition resulting in lower survival of fawns, and a less synchronous parturition that potentially increases susceptibility of neonates to predation). Our objectives were to compare rates of pregnancy, synchrony of parturition, and timing of parturition between exploited mule deer populations with a relatively high (Piceance, CO, USA; 26 males/100 females) and a relatively low (Monroe, UT, USA; 14 males/100 females) male/female ratio. We determined rates of pregnancy via ultrasonography and timing of parturition via vaginal implant transmitters. We found no differences in rates of pregnancy (98.6% and 96.6%; z = −0.821; P = 0.794), timing of parturition (estimate = 1.258; SE = 1.672; t = 0.752; P = 0.454), or synchrony of parturition (F = 1.073 P = 0.859) between Monroe Mountain and Piceance Basin, respectively. The relatively low male/female ratio on Monroe Mountain was not associated with a protracted period of parturition. This finding suggests that relatively low male/female ratios typical of heavily harvested populations do not influence population dynamics because recruitment remains unaffected. © 2014 The Wildlife Society.
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spelling doaj-art-02055356a35d4c7b849fa09e14ff03ea2025-08-20T02:49:20ZengWileyWildlife Society Bulletin2328-55402014-12-0138480681110.1002/wsb.450Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturitionEric D. Freeman0Randy T. Larsen1Mark E. Peterson2Charles R. Anderson Jr.3Kent R. Hersey4Brock R. Mcmillan5Department of Plant and Wildlife SciencesBrigham Young University275 WIDBProvoUT84602USADepartment of Plant and Wildlife SciencesThe Monte L. Bean Life Science MuseumBrigham Young University275 WIDBProvoUT84602USADepartment of FishWildlifeand Conservation BiologyColorado State University1474 Campus DeliveryFort CollinsCO80523USAColorado Parks and Wildlife711 Independent AvenueGrand JunctionCO81505USAUtah Division of Wildlife Resources1594 W North TempleSalt Lake CityUT84114USADepartment of Plant and Wildlife SciencesBrigham Young University275 WIDBProvoUT84602USAABSTRACT Evaluating how management practices influence the population dynamics of ungulates may enhance future management of these species. For example, in mule deer (Odocoileus hemionus), changes in male/female ratio due to male‐biased harvest may alter rates of pregnancy, timing of parturition, and synchrony of parturition if inadequate numbers of males are present to fertilize females during their first estrous cycle. If rates of pregnancy or parturition are influenced by decreased male/female ratios, recruitment may be reduced (e.g., fewer births, later parturition resulting in lower survival of fawns, and a less synchronous parturition that potentially increases susceptibility of neonates to predation). Our objectives were to compare rates of pregnancy, synchrony of parturition, and timing of parturition between exploited mule deer populations with a relatively high (Piceance, CO, USA; 26 males/100 females) and a relatively low (Monroe, UT, USA; 14 males/100 females) male/female ratio. We determined rates of pregnancy via ultrasonography and timing of parturition via vaginal implant transmitters. We found no differences in rates of pregnancy (98.6% and 96.6%; z = −0.821; P = 0.794), timing of parturition (estimate = 1.258; SE = 1.672; t = 0.752; P = 0.454), or synchrony of parturition (F = 1.073 P = 0.859) between Monroe Mountain and Piceance Basin, respectively. The relatively low male/female ratio on Monroe Mountain was not associated with a protracted period of parturition. This finding suggests that relatively low male/female ratios typical of heavily harvested populations do not influence population dynamics because recruitment remains unaffected. © 2014 The Wildlife Society.https://doi.org/10.1002/wsb.450male/female ratiomule deerOdocoileus hemionusrates of pregnancysex ratiosynchrony, timing of parturition
spellingShingle Eric D. Freeman
Randy T. Larsen
Mark E. Peterson
Charles R. Anderson Jr.
Kent R. Hersey
Brock R. Mcmillan
Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
Wildlife Society Bulletin
male/female ratio
mule deer
Odocoileus hemionus
rates of pregnancy
sex ratio
synchrony, timing of parturition
title Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
title_full Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
title_fullStr Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
title_full_unstemmed Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
title_short Effects of male‐biased harvest on mule deer: Implications for rates of pregnancy, synchrony, and timing of parturition
title_sort effects of male biased harvest on mule deer implications for rates of pregnancy synchrony and timing of parturition
topic male/female ratio
mule deer
Odocoileus hemionus
rates of pregnancy
sex ratio
synchrony, timing of parturition
url https://doi.org/10.1002/wsb.450
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