Evidence for source-sink dynamics in a regional population of arctic ground squirrels (Urocitellus parryii plesius)

Scott Donker

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Context. Variable demographic rates can manifest themselves between habitat types in the form of source-sink dynamics where populations in sink habitats would not exist without the addition of migrants from source habitats. Aims. Arctic ground squirrels (Urocitellus parryii pleisus (Osgood, 1900)) occupy a large geographic area in northern Canada and live in a variety of habitat types, including boreal forest, low-elevation meadows and alpine meadows, providing an opportunity to investigate the possible existence of sourceâ¿¿sink dynamics. Methods. We hypothesised that arctic ground squirrels in the south-western Yukon exhibit demographic characteristics indicative of sourceâ¿¿sink dynamics. Boreal forest habitat could be a sink in spite of previous high squirrel densities, whereas meadows could be a source. We investigated this by mark-recapture live-trapping and radio-telemetry. Key Results. In the boreal forest in the Kluane region, we found reduced recruitment, reduced population growth rates (l), and reduced survivorship for radio-collared individuals that moved from low-elevation meadows into the boreal forest. There was no evidence from radio-collared juveniles of dispersal from high-density ground squirrel populations in alpine meadows down into boreal forest. Conclusions. Boreal forest is a sink habitat for arctic ground squirrels. Sourceâ¿¿sink dynamics observed between low elevation meadow and boreal forest habitats appear to result from increased predation pressure in the boreal forest. The result has been a near extirpation of boreal forest arctic ground squirrels in the Kluane region since 1998. Implications. Because the source areas of low-elevation meadows occupy only 7-9% of the lowland habitat, recolonisation of boreal forest sites has been very slow. Whereas alpine populations remain high in 2011, boreal forest populations remain near zero. Alpine populations do not appear to be a source for the boreal forest.
Original languageEnglish
Pages (from-to)163-170
Number of pages8
JournalWildlife Research
Volume39
Issue number2
DOIs
Publication statusPublished - 2012
Externally publishedYes

Fingerprint

source-sink dynamics
squirrels
boreal forests
boreal forest
Arctic region
meadow
meadows
habitat
habitats
alpine meadows
forest habitats
habitat type
radio
Yukon Territory
sociodemographic characteristics
radiotelemetry
radio telemetry
recolonization
survivorship
trapping

Cite this

@article{303074db9cb7447daf433b76717f8973,
title = "Evidence for source-sink dynamics in a regional population of arctic ground squirrels (Urocitellus parryii plesius)",
abstract = "Context. Variable demographic rates can manifest themselves between habitat types in the form of source-sink dynamics where populations in sink habitats would not exist without the addition of migrants from source habitats. Aims. Arctic ground squirrels (Urocitellus parryii pleisus (Osgood, 1900)) occupy a large geographic area in northern Canada and live in a variety of habitat types, including boreal forest, low-elevation meadows and alpine meadows, providing an opportunity to investigate the possible existence of source{\^a}¿¿sink dynamics. Methods. We hypothesised that arctic ground squirrels in the south-western Yukon exhibit demographic characteristics indicative of source{\^a}¿¿sink dynamics. Boreal forest habitat could be a sink in spite of previous high squirrel densities, whereas meadows could be a source. We investigated this by mark-recapture live-trapping and radio-telemetry. Key Results. In the boreal forest in the Kluane region, we found reduced recruitment, reduced population growth rates (l), and reduced survivorship for radio-collared individuals that moved from low-elevation meadows into the boreal forest. There was no evidence from radio-collared juveniles of dispersal from high-density ground squirrel populations in alpine meadows down into boreal forest. Conclusions. Boreal forest is a sink habitat for arctic ground squirrels. Source{\^a}¿¿sink dynamics observed between low elevation meadow and boreal forest habitats appear to result from increased predation pressure in the boreal forest. The result has been a near extirpation of boreal forest arctic ground squirrels in the Kluane region since 1998. Implications. Because the source areas of low-elevation meadows occupy only 7-9{\%} of the lowland habitat, recolonisation of boreal forest sites has been very slow. Whereas alpine populations remain high in 2011, boreal forest populations remain near zero. Alpine populations do not appear to be a source for the boreal forest.",
keywords = "habitat-specific demography, Yukon Urocitellus parryii plesius.",
author = "Scott Donker",
year = "2012",
doi = "10.1071/WR11167",
language = "English",
volume = "39",
pages = "163--170",
journal = "Australian Wildlife Research",
issn = "1035-3712",
publisher = "CSIRO",
number = "2",

}

Evidence for source-sink dynamics in a regional population of arctic ground squirrels (Urocitellus parryii plesius). / Donker, Scott.

In: Wildlife Research, Vol. 39, No. 2, 2012, p. 163-170.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Evidence for source-sink dynamics in a regional population of arctic ground squirrels (Urocitellus parryii plesius)

AU - Donker, Scott

PY - 2012

Y1 - 2012

N2 - Context. Variable demographic rates can manifest themselves between habitat types in the form of source-sink dynamics where populations in sink habitats would not exist without the addition of migrants from source habitats. Aims. Arctic ground squirrels (Urocitellus parryii pleisus (Osgood, 1900)) occupy a large geographic area in northern Canada and live in a variety of habitat types, including boreal forest, low-elevation meadows and alpine meadows, providing an opportunity to investigate the possible existence of sourceâ¿¿sink dynamics. Methods. We hypothesised that arctic ground squirrels in the south-western Yukon exhibit demographic characteristics indicative of sourceâ¿¿sink dynamics. Boreal forest habitat could be a sink in spite of previous high squirrel densities, whereas meadows could be a source. We investigated this by mark-recapture live-trapping and radio-telemetry. Key Results. In the boreal forest in the Kluane region, we found reduced recruitment, reduced population growth rates (l), and reduced survivorship for radio-collared individuals that moved from low-elevation meadows into the boreal forest. There was no evidence from radio-collared juveniles of dispersal from high-density ground squirrel populations in alpine meadows down into boreal forest. Conclusions. Boreal forest is a sink habitat for arctic ground squirrels. Sourceâ¿¿sink dynamics observed between low elevation meadow and boreal forest habitats appear to result from increased predation pressure in the boreal forest. The result has been a near extirpation of boreal forest arctic ground squirrels in the Kluane region since 1998. Implications. Because the source areas of low-elevation meadows occupy only 7-9% of the lowland habitat, recolonisation of boreal forest sites has been very slow. Whereas alpine populations remain high in 2011, boreal forest populations remain near zero. Alpine populations do not appear to be a source for the boreal forest.

AB - Context. Variable demographic rates can manifest themselves between habitat types in the form of source-sink dynamics where populations in sink habitats would not exist without the addition of migrants from source habitats. Aims. Arctic ground squirrels (Urocitellus parryii pleisus (Osgood, 1900)) occupy a large geographic area in northern Canada and live in a variety of habitat types, including boreal forest, low-elevation meadows and alpine meadows, providing an opportunity to investigate the possible existence of sourceâ¿¿sink dynamics. Methods. We hypothesised that arctic ground squirrels in the south-western Yukon exhibit demographic characteristics indicative of sourceâ¿¿sink dynamics. Boreal forest habitat could be a sink in spite of previous high squirrel densities, whereas meadows could be a source. We investigated this by mark-recapture live-trapping and radio-telemetry. Key Results. In the boreal forest in the Kluane region, we found reduced recruitment, reduced population growth rates (l), and reduced survivorship for radio-collared individuals that moved from low-elevation meadows into the boreal forest. There was no evidence from radio-collared juveniles of dispersal from high-density ground squirrel populations in alpine meadows down into boreal forest. Conclusions. Boreal forest is a sink habitat for arctic ground squirrels. Sourceâ¿¿sink dynamics observed between low elevation meadow and boreal forest habitats appear to result from increased predation pressure in the boreal forest. The result has been a near extirpation of boreal forest arctic ground squirrels in the Kluane region since 1998. Implications. Because the source areas of low-elevation meadows occupy only 7-9% of the lowland habitat, recolonisation of boreal forest sites has been very slow. Whereas alpine populations remain high in 2011, boreal forest populations remain near zero. Alpine populations do not appear to be a source for the boreal forest.

KW - habitat-specific demography

KW - Yukon Urocitellus parryii plesius.

U2 - 10.1071/WR11167

DO - 10.1071/WR11167

M3 - Article

VL - 39

SP - 163

EP - 170

JO - Australian Wildlife Research

JF - Australian Wildlife Research

SN - 1035-3712

IS - 2

ER -