Investigating patterns and processes of demographic variation

environmental correlates of pre-breeding survival in red-billed choughs Pyrrhocorax pyrrhocorax

J. M. Reid, E. M. Bignal, S. Bignal, D. I. Mccracken, M. I. Bogdanova, P. Monaghan

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

1. Quantifying the pattern of temporal and spatial variation in demography, and identifying the factors that cause this variation, are essential steps towards understanding the structure and dynamics of any population.

2. One critical but understudied demographic rate is pre-breeding survival. We used long-term colour-ringing data to quantify temporal (among-year) and spatial (among-nest site) variation in pre-breeding survival in red-billed choughs (Pyrrhocorax pyrrhocorax) inhabiting Islay, Scotland, and identified environmental correlates of this variation.

3. Random-effects capture-mark-recapture models demonstrated substantial temporal and spatial process variance in first-year survival; survival from fledging to age 1 year varied markedly among choughs fledged in different years and fledged from different nest sites. Spatial variance exceeded temporal variance across choughs fledged from well-studied nest sites.

4. The best-supported models of temporal variation suggested that first-year survival was higher in years following high tipulid larvae abundance and when weather conditions favoured increased invertebrate productivity and/or availability to foraging choughs. These variables explained up to 80% of estimated temporal process variance.

5. The best-supported models of spatial variation suggested that first-year survival was higher in choughs fledged from nest sites that were further from exposed coasts and closer to flocking areas, and surrounded by better habitat and higher chough density. These variables explained up to 40% of estimated spatial process variance.

6. Importantly, spatio-temporal models indicated interactive effects of weather, tipulid abundance, local habitat and local chough density on first-year survival, suggesting that detrimental effects of poor weather and low tipulid abundance may be reduced in choughs fledged from nest sites surrounded by better foraging habitat and lower chough density.

7. These analyses demonstrate substantial temporal and small-scale spatial variation in pre-breeding survival, a key demographic rate, and indicate that this variation may reflect interactive effects of weather, prey abundance, habitat and geography. These patterns illustrate the value of holistic models of demographic variation, and indicate environmental factors that may limit the growth rate of Islay's protected chough population.

Original languageEnglish
Pages (from-to)777-788
Number of pages12
JournalJournal of Animal Ecology
Volume77
Issue number4
Early online date9 May 2008
DOIs
Publication statusPublished - Jul 2008

Keywords

  • juvenile survival
  • life-history variation
  • population growth rate
  • population regulation
  • territory quality
  • population-grwoth rate
  • postfledging survival
  • reproductive success
  • density-dependence
  • adult survival
  • dynamics
  • variability
  • climate
  • fitness
  • size

Cite this

Investigating patterns and processes of demographic variation : environmental correlates of pre-breeding survival in red-billed choughs Pyrrhocorax pyrrhocorax. / Reid, J. M.; Bignal, E. M.; Bignal, S.; Mccracken, D. I.; Bogdanova, M. I.; Monaghan, P.

In: Journal of Animal Ecology, Vol. 77, No. 4, 07.2008, p. 777-788.

Research output: Contribution to journalArticle

@article{1a601dd1cbe34c98adaeb51b4d7636ac,
title = "Investigating patterns and processes of demographic variation: environmental correlates of pre-breeding survival in red-billed choughs Pyrrhocorax pyrrhocorax",
abstract = "1. Quantifying the pattern of temporal and spatial variation in demography, and identifying the factors that cause this variation, are essential steps towards understanding the structure and dynamics of any population.2. One critical but understudied demographic rate is pre-breeding survival. We used long-term colour-ringing data to quantify temporal (among-year) and spatial (among-nest site) variation in pre-breeding survival in red-billed choughs (Pyrrhocorax pyrrhocorax) inhabiting Islay, Scotland, and identified environmental correlates of this variation.3. Random-effects capture-mark-recapture models demonstrated substantial temporal and spatial process variance in first-year survival; survival from fledging to age 1 year varied markedly among choughs fledged in different years and fledged from different nest sites. Spatial variance exceeded temporal variance across choughs fledged from well-studied nest sites.4. The best-supported models of temporal variation suggested that first-year survival was higher in years following high tipulid larvae abundance and when weather conditions favoured increased invertebrate productivity and/or availability to foraging choughs. These variables explained up to 80{\%} of estimated temporal process variance.5. The best-supported models of spatial variation suggested that first-year survival was higher in choughs fledged from nest sites that were further from exposed coasts and closer to flocking areas, and surrounded by better habitat and higher chough density. These variables explained up to 40{\%} of estimated spatial process variance.6. Importantly, spatio-temporal models indicated interactive effects of weather, tipulid abundance, local habitat and local chough density on first-year survival, suggesting that detrimental effects of poor weather and low tipulid abundance may be reduced in choughs fledged from nest sites surrounded by better foraging habitat and lower chough density.7. These analyses demonstrate substantial temporal and small-scale spatial variation in pre-breeding survival, a key demographic rate, and indicate that this variation may reflect interactive effects of weather, prey abundance, habitat and geography. These patterns illustrate the value of holistic models of demographic variation, and indicate environmental factors that may limit the growth rate of Islay's protected chough population.",
keywords = "juvenile survival, life-history variation, population growth rate, population regulation, territory quality, population-grwoth rate, postfledging survival, reproductive success, density-dependence, adult survival, dynamics, variability, climate, fitness, size",
author = "Reid, {J. M.} and Bignal, {E. M.} and S. Bignal and Mccracken, {D. I.} and Bogdanova, {M. I.} and P. Monaghan",
year = "2008",
month = "7",
doi = "10.1111/j.1365-2656.2008.01400.x",
language = "English",
volume = "77",
pages = "777--788",
journal = "Journal of Animal Ecology",
issn = "0021-8790",
publisher = "BLACKWELL PUBLISHING LTD",
number = "4",

}

TY - JOUR

T1 - Investigating patterns and processes of demographic variation

T2 - environmental correlates of pre-breeding survival in red-billed choughs Pyrrhocorax pyrrhocorax

AU - Reid, J. M.

AU - Bignal, E. M.

AU - Bignal, S.

AU - Mccracken, D. I.

AU - Bogdanova, M. I.

AU - Monaghan, P.

PY - 2008/7

Y1 - 2008/7

N2 - 1. Quantifying the pattern of temporal and spatial variation in demography, and identifying the factors that cause this variation, are essential steps towards understanding the structure and dynamics of any population.2. One critical but understudied demographic rate is pre-breeding survival. We used long-term colour-ringing data to quantify temporal (among-year) and spatial (among-nest site) variation in pre-breeding survival in red-billed choughs (Pyrrhocorax pyrrhocorax) inhabiting Islay, Scotland, and identified environmental correlates of this variation.3. Random-effects capture-mark-recapture models demonstrated substantial temporal and spatial process variance in first-year survival; survival from fledging to age 1 year varied markedly among choughs fledged in different years and fledged from different nest sites. Spatial variance exceeded temporal variance across choughs fledged from well-studied nest sites.4. The best-supported models of temporal variation suggested that first-year survival was higher in years following high tipulid larvae abundance and when weather conditions favoured increased invertebrate productivity and/or availability to foraging choughs. These variables explained up to 80% of estimated temporal process variance.5. The best-supported models of spatial variation suggested that first-year survival was higher in choughs fledged from nest sites that were further from exposed coasts and closer to flocking areas, and surrounded by better habitat and higher chough density. These variables explained up to 40% of estimated spatial process variance.6. Importantly, spatio-temporal models indicated interactive effects of weather, tipulid abundance, local habitat and local chough density on first-year survival, suggesting that detrimental effects of poor weather and low tipulid abundance may be reduced in choughs fledged from nest sites surrounded by better foraging habitat and lower chough density.7. These analyses demonstrate substantial temporal and small-scale spatial variation in pre-breeding survival, a key demographic rate, and indicate that this variation may reflect interactive effects of weather, prey abundance, habitat and geography. These patterns illustrate the value of holistic models of demographic variation, and indicate environmental factors that may limit the growth rate of Islay's protected chough population.

AB - 1. Quantifying the pattern of temporal and spatial variation in demography, and identifying the factors that cause this variation, are essential steps towards understanding the structure and dynamics of any population.2. One critical but understudied demographic rate is pre-breeding survival. We used long-term colour-ringing data to quantify temporal (among-year) and spatial (among-nest site) variation in pre-breeding survival in red-billed choughs (Pyrrhocorax pyrrhocorax) inhabiting Islay, Scotland, and identified environmental correlates of this variation.3. Random-effects capture-mark-recapture models demonstrated substantial temporal and spatial process variance in first-year survival; survival from fledging to age 1 year varied markedly among choughs fledged in different years and fledged from different nest sites. Spatial variance exceeded temporal variance across choughs fledged from well-studied nest sites.4. The best-supported models of temporal variation suggested that first-year survival was higher in years following high tipulid larvae abundance and when weather conditions favoured increased invertebrate productivity and/or availability to foraging choughs. These variables explained up to 80% of estimated temporal process variance.5. The best-supported models of spatial variation suggested that first-year survival was higher in choughs fledged from nest sites that were further from exposed coasts and closer to flocking areas, and surrounded by better habitat and higher chough density. These variables explained up to 40% of estimated spatial process variance.6. Importantly, spatio-temporal models indicated interactive effects of weather, tipulid abundance, local habitat and local chough density on first-year survival, suggesting that detrimental effects of poor weather and low tipulid abundance may be reduced in choughs fledged from nest sites surrounded by better foraging habitat and lower chough density.7. These analyses demonstrate substantial temporal and small-scale spatial variation in pre-breeding survival, a key demographic rate, and indicate that this variation may reflect interactive effects of weather, prey abundance, habitat and geography. These patterns illustrate the value of holistic models of demographic variation, and indicate environmental factors that may limit the growth rate of Islay's protected chough population.

KW - juvenile survival

KW - life-history variation

KW - population growth rate

KW - population regulation

KW - territory quality

KW - population-grwoth rate

KW - postfledging survival

KW - reproductive success

KW - density-dependence

KW - adult survival

KW - dynamics

KW - variability

KW - climate

KW - fitness

KW - size

U2 - 10.1111/j.1365-2656.2008.01400.x

DO - 10.1111/j.1365-2656.2008.01400.x

M3 - Article

VL - 77

SP - 777

EP - 788

JO - Journal of Animal Ecology

JF - Journal of Animal Ecology

SN - 0021-8790

IS - 4

ER -