Species- and sex-specific connectivity effects of habitat fragmentation in a suite of woodland birds

J. N. Amos, K. Harrisson, J. Q. Radford, Matt White, Graeme Newell, Ralph MAC NALLY, Paul Sunnucks, Alexandra Pavlova

    Research output: Contribution to journalArticle

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    Abstract

    Loss of functional connectivity following habitat loss and fragmentation could drive species declines. A comprehensive understanding of fragmentation effects on functional connectivity of an ecological assemblage requires investigation of multiple species with different mobilities, at different spatial scales, for each sex, and in different landscapes. Based on published data on mobility and ecological responses to fragmentation of 10 woodlanddependent birds, and using simulation studies, we predicted that (1) fragmentation would impede dispersal and gene flow of eight ''decliners'' (species that disappear from suitable patches when landscape-level tree cover falls below species-specific thresholds), but not of two ''tolerant'' species (whose occurrence in suitable habitat patches is independent of landscape tree cover); and that fragmentation effects would be stronger (2) in the least mobile species, (3) in the more philopatric sex, and (4) in the more fragmented region. We tested these predictions by evaluating spatially explicit isolation-by-landscape-resistance models of gene flow in fragmented landscapes across a 50 × 170 km study area in central Victoria, Australia, using individual and population genetic distances. To account for sex-biased dispersal and potential scale- and configuration-specific effects, we fitted models specific to sex and geographic zones. As predicted, four of the least mobile decliners showed evidence of reduced genetic connectivity. The responses were strongly sex specific, but in opposite directions in the two most sedentary species. Both tolerant species and (unexpectedly) four of the more mobile decliners showed no reduction in gene flow. This is unlikely to be due to time lags because more mobile species develop genetic signatures of fragmentation faster than do less mobile ones. Weaker genetic effects were observed in the geographic zone with more aggregated vegetation, consistent with gene flow being unimpeded by landscape structure. Our results indicate that for all but the most sedentary species in our system, the movement of the more dispersive sex (females in most cases) maintains overall genetic connectivity across fragmented landscapes in the study area, despite some small-scale effects on the more philopatric sex for some species. Nevertheless, to improve population viability for the less mobile bird species, structural landscape connectivity must be increased.

    Original languageEnglish
    Pages (from-to)1556-1568
    Number of pages13
    JournalEcology
    Volume95
    Issue number6
    DOIs
    Publication statusPublished - 2014

    Fingerprint

    habitat fragmentation
    connectivity
    woodlands
    woodland
    bird
    gender
    birds
    gene flow
    fragmentation
    Victoria (Australia)
    effect
    habitat destruction
    species occurrence
    landscape structure
    genetic distance
    scale effect
    habitat loss
    population genetics
    viability
    vegetation

    Cite this

    Amos, J. N., Harrisson, K., Radford, J. Q., White, M., Newell, G., MAC NALLY, R., ... Pavlova, A. (2014). Species- and sex-specific connectivity effects of habitat fragmentation in a suite of woodland birds. Ecology, 95(6), 1556-1568. https://doi.org/10.1890/13-1328.1
    Amos, J. N. ; Harrisson, K. ; Radford, J. Q. ; White, Matt ; Newell, Graeme ; MAC NALLY, Ralph ; Sunnucks, Paul ; Pavlova, Alexandra. / Species- and sex-specific connectivity effects of habitat fragmentation in a suite of woodland birds. In: Ecology. 2014 ; Vol. 95, No. 6. pp. 1556-1568.
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    Amos, JN, Harrisson, K, Radford, JQ, White, M, Newell, G, MAC NALLY, R, Sunnucks, P & Pavlova, A 2014, 'Species- and sex-specific connectivity effects of habitat fragmentation in a suite of woodland birds', Ecology, vol. 95, no. 6, pp. 1556-1568. https://doi.org/10.1890/13-1328.1

    Species- and sex-specific connectivity effects of habitat fragmentation in a suite of woodland birds. / Amos, J. N.; Harrisson, K.; Radford, J. Q.; White, Matt; Newell, Graeme; MAC NALLY, Ralph; Sunnucks, Paul; Pavlova, Alexandra.

    In: Ecology, Vol. 95, No. 6, 2014, p. 1556-1568.

    Research output: Contribution to journalArticle

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    AU - Harrisson, K.

    AU - Radford, J. Q.

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    KW - isolation-by-resistance

    KW - landscape genetics

    KW - philopatry

    KW - structural connectivity

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    KW - Australia

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    KW - Functional connectivity

    KW - Isolation-by-resistance

    KW - Woodland birds

    KW - Isolation-bydistance

    KW - Philopatry

    KW - Landscape genetics

    KW - Structural connectivity

    KW - Dispersal

    KW - Habitat fragmentation

    KW - woodland birds

    KW - Victoria, Australia

    KW - isolation-by-distance

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