Two decades of cumulative impacts to survivorship of endangered California condors in California

Terra R. Kelly, Bruce A. Rideout, Jesse Grantham, Joseph Brandt, L. Joseph Burnett, Kelly J. Sorenson, Daniel George, Alacia Welch, David Moen, James Rasico, Matthew Johnson, Carie Battistone, Christine K Johnson

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We investigated threats to the California condor (Gymnogyps californianus), a flagship endangered species, using individual data on survival during a 20. year period of intensive recovery efforts. Over the two decades of reintroductions, condors in California had an estimated median survival time of 7.8. years suggesting that 50% of condors are expected to survive in the wild long enough to contribute to recruitment. In general, annual mortality rates exceeded levels necessary for a stable population; however, mortality declined, reaching levels needed for population stability, during the second decade of re-establishment. Intensive management practices, including utility pole aversion training and clinical interventions to prevent lead-related deaths likely contributed to the decrease in mortality rates. Utility line collision and/or electrocution was an important factor causing mortality over the two decades; though, this threat has largely been mitigated through management and targeted efforts in high-risk areas. In the past, wildfires were not considered a major threat to survival of free-flying condors. However, our analyses suggest that forest fires are significantly linked to the hazard of death, and increased wildfire activity in California highlights this population's vulnerability to catastrophic losses from forest fire. Lead poisoning, which was a major driver in the population's decline, was a leading cause of death accounting for the greatest adult mortality, and lead exposure remains the most significant threat. Recent lead ammunition reduction efforts in the condor range in California hold promise for improving the recovery potential for this population.

Original languageEnglish (US)
Pages (from-to)391-399
Number of pages9
JournalBiological Conservation
Volume191
DOIs
StatePublished - Nov 1 2015

Fingerprint

survivorship
survival rate
mortality
forest fires
death
wildfires
forest fire
wildfire
utility poles
lead poisoning
cause of death
reintroduction
population decline
poisoning
endangered species
management practice
vulnerability
flight
collision
Gymnogyps californianus

Keywords

  • California condor
  • Endangered species
  • Forest fire
  • Lead poisoning
  • Population decline
  • Survival

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Nature and Landscape Conservation

Cite this

Two decades of cumulative impacts to survivorship of endangered California condors in California. / Kelly, Terra R.; Rideout, Bruce A.; Grantham, Jesse; Brandt, Joseph; Burnett, L. Joseph; Sorenson, Kelly J.; George, Daniel; Welch, Alacia; Moen, David; Rasico, James; Johnson, Matthew; Battistone, Carie; Johnson, Christine K.

In: Biological Conservation, Vol. 191, 01.11.2015, p. 391-399.

Research output: Contribution to journalArticle

Kelly, TR, Rideout, BA, Grantham, J, Brandt, J, Burnett, LJ, Sorenson, KJ, George, D, Welch, A, Moen, D, Rasico, J, Johnson, M, Battistone, C & Johnson, CK 2015, 'Two decades of cumulative impacts to survivorship of endangered California condors in California', Biological Conservation, vol. 191, pp. 391-399. https://doi.org/10.1016/j.biocon.2015.07.012
Kelly, Terra R. ; Rideout, Bruce A. ; Grantham, Jesse ; Brandt, Joseph ; Burnett, L. Joseph ; Sorenson, Kelly J. ; George, Daniel ; Welch, Alacia ; Moen, David ; Rasico, James ; Johnson, Matthew ; Battistone, Carie ; Johnson, Christine K. / Two decades of cumulative impacts to survivorship of endangered California condors in California. In: Biological Conservation. 2015 ; Vol. 191. pp. 391-399.
@article{29ce297fdc2d42919f629665c688ec34,
title = "Two decades of cumulative impacts to survivorship of endangered California condors in California",
abstract = "We investigated threats to the California condor (Gymnogyps californianus), a flagship endangered species, using individual data on survival during a 20. year period of intensive recovery efforts. Over the two decades of reintroductions, condors in California had an estimated median survival time of 7.8. years suggesting that 50{\%} of condors are expected to survive in the wild long enough to contribute to recruitment. In general, annual mortality rates exceeded levels necessary for a stable population; however, mortality declined, reaching levels needed for population stability, during the second decade of re-establishment. Intensive management practices, including utility pole aversion training and clinical interventions to prevent lead-related deaths likely contributed to the decrease in mortality rates. Utility line collision and/or electrocution was an important factor causing mortality over the two decades; though, this threat has largely been mitigated through management and targeted efforts in high-risk areas. In the past, wildfires were not considered a major threat to survival of free-flying condors. However, our analyses suggest that forest fires are significantly linked to the hazard of death, and increased wildfire activity in California highlights this population's vulnerability to catastrophic losses from forest fire. Lead poisoning, which was a major driver in the population's decline, was a leading cause of death accounting for the greatest adult mortality, and lead exposure remains the most significant threat. Recent lead ammunition reduction efforts in the condor range in California hold promise for improving the recovery potential for this population.",
keywords = "California condor, Endangered species, Forest fire, Lead poisoning, Population decline, Survival",
author = "Kelly, {Terra R.} and Rideout, {Bruce A.} and Jesse Grantham and Joseph Brandt and Burnett, {L. Joseph} and Sorenson, {Kelly J.} and Daniel George and Alacia Welch and David Moen and James Rasico and Matthew Johnson and Carie Battistone and Johnson, {Christine K}",
year = "2015",
month = "11",
day = "1",
doi = "10.1016/j.biocon.2015.07.012",
language = "English (US)",
volume = "191",
pages = "391--399",
journal = "Biological Conservation",
issn = "0006-3207",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Two decades of cumulative impacts to survivorship of endangered California condors in California

AU - Kelly, Terra R.

AU - Rideout, Bruce A.

AU - Grantham, Jesse

AU - Brandt, Joseph

AU - Burnett, L. Joseph

AU - Sorenson, Kelly J.

AU - George, Daniel

AU - Welch, Alacia

AU - Moen, David

AU - Rasico, James

AU - Johnson, Matthew

AU - Battistone, Carie

AU - Johnson, Christine K

PY - 2015/11/1

Y1 - 2015/11/1

N2 - We investigated threats to the California condor (Gymnogyps californianus), a flagship endangered species, using individual data on survival during a 20. year period of intensive recovery efforts. Over the two decades of reintroductions, condors in California had an estimated median survival time of 7.8. years suggesting that 50% of condors are expected to survive in the wild long enough to contribute to recruitment. In general, annual mortality rates exceeded levels necessary for a stable population; however, mortality declined, reaching levels needed for population stability, during the second decade of re-establishment. Intensive management practices, including utility pole aversion training and clinical interventions to prevent lead-related deaths likely contributed to the decrease in mortality rates. Utility line collision and/or electrocution was an important factor causing mortality over the two decades; though, this threat has largely been mitigated through management and targeted efforts in high-risk areas. In the past, wildfires were not considered a major threat to survival of free-flying condors. However, our analyses suggest that forest fires are significantly linked to the hazard of death, and increased wildfire activity in California highlights this population's vulnerability to catastrophic losses from forest fire. Lead poisoning, which was a major driver in the population's decline, was a leading cause of death accounting for the greatest adult mortality, and lead exposure remains the most significant threat. Recent lead ammunition reduction efforts in the condor range in California hold promise for improving the recovery potential for this population.

AB - We investigated threats to the California condor (Gymnogyps californianus), a flagship endangered species, using individual data on survival during a 20. year period of intensive recovery efforts. Over the two decades of reintroductions, condors in California had an estimated median survival time of 7.8. years suggesting that 50% of condors are expected to survive in the wild long enough to contribute to recruitment. In general, annual mortality rates exceeded levels necessary for a stable population; however, mortality declined, reaching levels needed for population stability, during the second decade of re-establishment. Intensive management practices, including utility pole aversion training and clinical interventions to prevent lead-related deaths likely contributed to the decrease in mortality rates. Utility line collision and/or electrocution was an important factor causing mortality over the two decades; though, this threat has largely been mitigated through management and targeted efforts in high-risk areas. In the past, wildfires were not considered a major threat to survival of free-flying condors. However, our analyses suggest that forest fires are significantly linked to the hazard of death, and increased wildfire activity in California highlights this population's vulnerability to catastrophic losses from forest fire. Lead poisoning, which was a major driver in the population's decline, was a leading cause of death accounting for the greatest adult mortality, and lead exposure remains the most significant threat. Recent lead ammunition reduction efforts in the condor range in California hold promise for improving the recovery potential for this population.

KW - California condor

KW - Endangered species

KW - Forest fire

KW - Lead poisoning

KW - Population decline

KW - Survival

UR - http://www.scopus.com/inward/record.url?scp=84938941244&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84938941244&partnerID=8YFLogxK

U2 - 10.1016/j.biocon.2015.07.012

DO - 10.1016/j.biocon.2015.07.012

M3 - Article

AN - SCOPUS:84938941244

VL - 191

SP - 391

EP - 399

JO - Biological Conservation

JF - Biological Conservation

SN - 0006-3207

ER -