A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark
The Streaked Horned Lark (Eremophila alpestris strigata) is listed as endangered by the State of Washington, USA and by Canada under the Species at Risk Act and is also classified as a federal candidate for listing under the Endangered Species Act in the USA. A substantial portion of Streaked Horned...
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Resilience Alliance
2011
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ftdoajarticles:oai:doaj.org/article:2e2da91d49b64ea981225bc54aed8ae0 2023-05-15T16:06:21+02:00 A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark Alaine F. Camfield Scott F. Pearson Kathy Martin 2011-12-01T00:00:00Z https://doi.org/10.5751/ACE-00467-060204 https://doaj.org/article/2e2da91d49b64ea981225bc54aed8ae0 EN eng Resilience Alliance http://www.ace-eco.org/vol6/iss2/art4/ https://doaj.org/toc/1712-6568 1712-6568 doi:10.5751/ACE-00467-060204 https://doaj.org/article/2e2da91d49b64ea981225bc54aed8ae0 Avian Conservation and Ecology, Vol 6, Iss 2, p 4 (2011) demography Eremophila alpestris strigata Life-Stage Simulation Analysis population modeling Streaked Horned Lark Plant culture SB1-1110 Environmental sciences GE1-350 Plant ecology QK900-989 article 2011 ftdoajarticles https://doi.org/10.5751/ACE-00467-060204 2022-12-31T11:31:15Z The Streaked Horned Lark (Eremophila alpestris strigata) is listed as endangered by the State of Washington, USA and by Canada under the Species at Risk Act and is also classified as a federal candidate for listing under the Endangered Species Act in the USA. A substantial portion of Streaked Horned Lark habitat has been lost or degraded, and range contraction has occurred in Oregon, Washington, and British Columbia. We estimate the vital rates (fecundity, adult and juvenile survival) and population growth rate (λ) for Streaked Horned Larks breeding in Washington, USA and conduct a Life-Stage Simulation Analysis (LSA) to evaluate which vital rate has the greatest influence on λ. We simulated changes in the three vital rates to examine how much they would need to be adjusted either independently or in concert to achieve a stable Streaked Horned Lark population (λ = 1). We also evaluated which fecundity component (the number of fledglings per egg laid or renesting interval) had the greatest impact on λ. The estimate of population growth suggests that Streaked Horned Larks in Washington are declining rapidly (λ = 0.62 ± 0.10) and that local breeding sites are not sustainable without immigration. The LSA results indicate that adult survival had the greatest influence on λ, followed by juvenile survival and fecundity. However, increases in vital rates led to λ = 1 only when adult survival was raised from 0.47 to 0.85, juvenile survival from 0.17 to 0.58, and fecundity from 0.91 to 3.09. Increases in breeding success and decreases in the renesting interval influenced λ similarly; however, λ did not reach 1 even when breeding success was raised to 100% or renesting intervals were reduced to 1 day. Only when all three vital rates were increased simultaneously did λ approach 1 without requiring highly unrealistic increases in each vital rate. We conclude that conservation activities need to target all or multiple vital rates to be successful. The baseline data presented here and subsequent efforts to manage Streaked ... Article in Journal/Newspaper Eremophila alpestris Directory of Open Access Journals: DOAJ Articles Canada British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Avian Conservation and Ecology 6 2 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
demography Eremophila alpestris strigata Life-Stage Simulation Analysis population modeling Streaked Horned Lark Plant culture SB1-1110 Environmental sciences GE1-350 Plant ecology QK900-989 |
spellingShingle |
demography Eremophila alpestris strigata Life-Stage Simulation Analysis population modeling Streaked Horned Lark Plant culture SB1-1110 Environmental sciences GE1-350 Plant ecology QK900-989 Alaine F. Camfield Scott F. Pearson Kathy Martin A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
topic_facet |
demography Eremophila alpestris strigata Life-Stage Simulation Analysis population modeling Streaked Horned Lark Plant culture SB1-1110 Environmental sciences GE1-350 Plant ecology QK900-989 |
description |
The Streaked Horned Lark (Eremophila alpestris strigata) is listed as endangered by the State of Washington, USA and by Canada under the Species at Risk Act and is also classified as a federal candidate for listing under the Endangered Species Act in the USA. A substantial portion of Streaked Horned Lark habitat has been lost or degraded, and range contraction has occurred in Oregon, Washington, and British Columbia. We estimate the vital rates (fecundity, adult and juvenile survival) and population growth rate (λ) for Streaked Horned Larks breeding in Washington, USA and conduct a Life-Stage Simulation Analysis (LSA) to evaluate which vital rate has the greatest influence on λ. We simulated changes in the three vital rates to examine how much they would need to be adjusted either independently or in concert to achieve a stable Streaked Horned Lark population (λ = 1). We also evaluated which fecundity component (the number of fledglings per egg laid or renesting interval) had the greatest impact on λ. The estimate of population growth suggests that Streaked Horned Larks in Washington are declining rapidly (λ = 0.62 ± 0.10) and that local breeding sites are not sustainable without immigration. The LSA results indicate that adult survival had the greatest influence on λ, followed by juvenile survival and fecundity. However, increases in vital rates led to λ = 1 only when adult survival was raised from 0.47 to 0.85, juvenile survival from 0.17 to 0.58, and fecundity from 0.91 to 3.09. Increases in breeding success and decreases in the renesting interval influenced λ similarly; however, λ did not reach 1 even when breeding success was raised to 100% or renesting intervals were reduced to 1 day. Only when all three vital rates were increased simultaneously did λ approach 1 without requiring highly unrealistic increases in each vital rate. We conclude that conservation activities need to target all or multiple vital rates to be successful. The baseline data presented here and subsequent efforts to manage Streaked ... |
format |
Article in Journal/Newspaper |
author |
Alaine F. Camfield Scott F. Pearson Kathy Martin |
author_facet |
Alaine F. Camfield Scott F. Pearson Kathy Martin |
author_sort |
Alaine F. Camfield |
title |
A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
title_short |
A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
title_full |
A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
title_fullStr |
A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
title_full_unstemmed |
A Demographic Model to Evaluate Population Declines in the Endangered Streaked Horned Lark |
title_sort |
demographic model to evaluate population declines in the endangered streaked horned lark |
publisher |
Resilience Alliance |
publishDate |
2011 |
url |
https://doi.org/10.5751/ACE-00467-060204 https://doaj.org/article/2e2da91d49b64ea981225bc54aed8ae0 |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) |
geographic |
Canada British Columbia |
geographic_facet |
Canada British Columbia |
genre |
Eremophila alpestris |
genre_facet |
Eremophila alpestris |
op_source |
Avian Conservation and Ecology, Vol 6, Iss 2, p 4 (2011) |
op_relation |
http://www.ace-eco.org/vol6/iss2/art4/ https://doaj.org/toc/1712-6568 1712-6568 doi:10.5751/ACE-00467-060204 https://doaj.org/article/2e2da91d49b64ea981225bc54aed8ae0 |
op_doi |
https://doi.org/10.5751/ACE-00467-060204 |
container_title |
Avian Conservation and Ecology |
container_volume |
6 |
container_issue |
2 |
_version_ |
1766402242196275200 |