Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem

Abstract For various temperate ungulate species, recent research has highlighted the potential for spring vegetation phenology (“green‐up”) to influence individual condition, with purported benefits to population productivity. However, few studies have been able to measure the benefit on vital rates...

Full description

Bibliographic Details
Main Authors: Owen R. Bidder, Thomas Connor, Juan M. Morales, Gregory J. M. Rickbeil, Jerod A. Merkle, Rebecca K. Fuda, Jared D. Rogerson, Brandon M. Scurlock, William H. Edwards, Eric K. Cole, Douglas E. McWhirter, Alyson B. Courtemanch, Sarah Dewey, Matthew J. Kauffman, Daniel R. MacNulty, Johan T. duToit, Daniel R. Stahler, Arthur D. Middleton
Format: Article
Language:English
Published: Wiley 2023-12-01
Series:Ecosphere
Subjects:
Online Access:https://doi.org/10.1002/ecs2.4694
_version_ 1827397259375935488
author Owen R. Bidder
Thomas Connor
Juan M. Morales
Gregory J. M. Rickbeil
Jerod A. Merkle
Rebecca K. Fuda
Jared D. Rogerson
Brandon M. Scurlock
William H. Edwards
Eric K. Cole
Douglas E. McWhirter
Alyson B. Courtemanch
Sarah Dewey
Matthew J. Kauffman
Daniel R. MacNulty
Johan T. duToit
Daniel R. Stahler
Arthur D. Middleton
author_facet Owen R. Bidder
Thomas Connor
Juan M. Morales
Gregory J. M. Rickbeil
Jerod A. Merkle
Rebecca K. Fuda
Jared D. Rogerson
Brandon M. Scurlock
William H. Edwards
Eric K. Cole
Douglas E. McWhirter
Alyson B. Courtemanch
Sarah Dewey
Matthew J. Kauffman
Daniel R. MacNulty
Johan T. duToit
Daniel R. Stahler
Arthur D. Middleton
author_sort Owen R. Bidder
collection DOAJ
description Abstract For various temperate ungulate species, recent research has highlighted the potential for spring vegetation phenology (“green‐up”) to influence individual condition, with purported benefits to population productivity. However, few studies have been able to measure the benefit on vital rates directly, and fewer still have investigated the comparative influence of other phenological periods on ungulate vital rates. In this study, we tracked phenological changes throughout the duration of the growing season and examined how their timing affected the probability of pregnancy in an ungulate population. We did this for elk (Cervus canadensis) across the Greater Yellowstone Ecosystem (GYE) by sampling 1106 adult females in winter at 25 sites over a 13‐year period and assessing sources of variation in pregnancy using a Bayesian hierarchical model. Pregnancy rates were generally high across the GYE (82.4%), and the primary influences on probability of pregnancy were the timing of vegetation senescence (“brown‐down”) in autumn and exposure to the reproductive disease brucellosis. Earlier forage brown‐down in fall negatively influenced the probability of pregnancy of elk aged 6–9 years by an estimated 17.2% within the range (ca. 32 days) of observed brown‐down end dates. While summer habitat quality has been inferred to influence elk pregnancy previously, our findings specify the key influence of foraging conditions later in the seasonal cycle, immediately before the breeding season. The reproductive disease brucellosis was also an important factor, reducing the probability of pregnancy by 12.4% in elk in the 6‐ to 9‐year age class. Because pregnancy was tested before most disease‐induced abortions occur, the apparent mechanism for this effect is a prolonged reduction in fertility beyond the period of initial exposure in which fetal mortality is typically expected. Our results prompt greater scrutiny of the combined effects of late‐season phenology and disease on reproductive rates and population productivity in temperate ungulates.
first_indexed 2024-03-08T19:05:43Z
format Article
id doaj.art-5ed3894de7e247fb8a02b0a4b92537ad
institution Directory Open Access Journal
issn 2150-8925
language English
last_indexed 2024-03-08T19:05:43Z
publishDate 2023-12-01
publisher Wiley
record_format Article
series Ecosphere
spelling doaj.art-5ed3894de7e247fb8a02b0a4b92537ad2023-12-27T23:58:35ZengWileyEcosphere2150-89252023-12-011412n/an/a10.1002/ecs2.4694Forage senescence and disease influence elk pregnancy across the Greater Yellowstone EcosystemOwen R. Bidder0Thomas Connor1Juan M. Morales2Gregory J. M. Rickbeil3Jerod A. Merkle4Rebecca K. Fuda5Jared D. Rogerson6Brandon M. Scurlock7William H. Edwards8Eric K. Cole9Douglas E. McWhirter10Alyson B. Courtemanch11Sarah Dewey12Matthew J. Kauffman13Daniel R. MacNulty14Johan T. duToit15Daniel R. Stahler16Arthur D. Middleton17Department of Environmental Science, Policy, and Management University of California, Berkeley Berkeley California USADepartment of Environmental Science, Policy, and Management University of California, Berkeley Berkeley California USASchool of Biodiversity, One Health, and Veterinary Medicine University of Glasgow Glasgow ScotlandDepartment of Environmental Science, Policy, and Management University of California, Berkeley Berkeley California USADepartment of Zoology and Physiology University of Wyoming Laramie Wyoming USAWyoming Game and Fish Department Pinedale Wyoming USAWyoming Game and Fish Department Pinedale Wyoming USAWyoming Game and Fish Department Pinedale Wyoming USAWyoming Game and Fish Wildlife Health Laboratory Laramie Wyoming USANational Elk Refuge U.S. Fish and Wildlife Service Jackson Wyoming USAWyoming Game and Fish Department Jackson Wyoming USAWyoming Game and Fish Department Jackson Wyoming USANational Park Service Grand Teton National Park Moose Wyoming USAU.S. Geological Survey, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology University of Wyoming Laramie Wyoming USADepartment of Wildland Resources Utah State University Logan Utah USADepartment of Wildland Resources Utah State University Logan Utah USAYellowstone Center for Resources National Park Service Yellowstone National Park Wyoming USADepartment of Environmental Science, Policy, and Management University of California, Berkeley Berkeley California USAAbstract For various temperate ungulate species, recent research has highlighted the potential for spring vegetation phenology (“green‐up”) to influence individual condition, with purported benefits to population productivity. However, few studies have been able to measure the benefit on vital rates directly, and fewer still have investigated the comparative influence of other phenological periods on ungulate vital rates. In this study, we tracked phenological changes throughout the duration of the growing season and examined how their timing affected the probability of pregnancy in an ungulate population. We did this for elk (Cervus canadensis) across the Greater Yellowstone Ecosystem (GYE) by sampling 1106 adult females in winter at 25 sites over a 13‐year period and assessing sources of variation in pregnancy using a Bayesian hierarchical model. Pregnancy rates were generally high across the GYE (82.4%), and the primary influences on probability of pregnancy were the timing of vegetation senescence (“brown‐down”) in autumn and exposure to the reproductive disease brucellosis. Earlier forage brown‐down in fall negatively influenced the probability of pregnancy of elk aged 6–9 years by an estimated 17.2% within the range (ca. 32 days) of observed brown‐down end dates. While summer habitat quality has been inferred to influence elk pregnancy previously, our findings specify the key influence of foraging conditions later in the seasonal cycle, immediately before the breeding season. The reproductive disease brucellosis was also an important factor, reducing the probability of pregnancy by 12.4% in elk in the 6‐ to 9‐year age class. Because pregnancy was tested before most disease‐induced abortions occur, the apparent mechanism for this effect is a prolonged reduction in fertility beyond the period of initial exposure in which fetal mortality is typically expected. Our results prompt greater scrutiny of the combined effects of late‐season phenology and disease on reproductive rates and population productivity in temperate ungulates.https://doi.org/10.1002/ecs2.4694animal ecologydisease ecologyelkpopulation ecologywildlife behavior
spellingShingle Owen R. Bidder
Thomas Connor
Juan M. Morales
Gregory J. M. Rickbeil
Jerod A. Merkle
Rebecca K. Fuda
Jared D. Rogerson
Brandon M. Scurlock
William H. Edwards
Eric K. Cole
Douglas E. McWhirter
Alyson B. Courtemanch
Sarah Dewey
Matthew J. Kauffman
Daniel R. MacNulty
Johan T. duToit
Daniel R. Stahler
Arthur D. Middleton
Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
Ecosphere
animal ecology
disease ecology
elk
population ecology
wildlife behavior
title Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
title_full Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
title_fullStr Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
title_full_unstemmed Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
title_short Forage senescence and disease influence elk pregnancy across the Greater Yellowstone Ecosystem
title_sort forage senescence and disease influence elk pregnancy across the greater yellowstone ecosystem
topic animal ecology
disease ecology
elk
population ecology
wildlife behavior
url https://doi.org/10.1002/ecs2.4694
work_keys_str_mv AT owenrbidder foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT thomasconnor foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT juanmmorales foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT gregoryjmrickbeil foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT jerodamerkle foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT rebeccakfuda foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT jareddrogerson foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT brandonmscurlock foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT williamhedwards foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT erickcole foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT douglasemcwhirter foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT alysonbcourtemanch foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT sarahdewey foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT matthewjkauffman foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT danielrmacnulty foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT johantdutoit foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT danielrstahler foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem
AT arthurdmiddleton foragesenescenceanddiseaseinfluenceelkpregnancyacrossthegreateryellowstoneecosystem