| Publication Type: | Journal Article |
| Year of Publication: | 2014 |
| Authors: | Davies, J, Arthur, D, White, S |
| Journal: | Bird Study |
| Volume: | 61 |
| Issue: | 2 |
| Date Published: | 2014 |
| ISBN Number: | 0006-3657 |
| Keywords: | Turdidae, Turdus, Turdus torquatus |
| Abstract: | Capsule Territory habitat influenced clutch size and within-brood variability of chick condition in Ring Ouzel Turdus torquatus.Aims To assess the relationship of Ring Ouzel productivity and chick condition with territory habitat, in order to improve understanding of the importance of breeding habitat for population change.Methods Productivity and chick condition were recorded for Ring Ouzel pairs in a small area of upland Scotland and these were related to vegetation and physical characteristics for all breeding territories using General Linear Models.Results We found that clutch size and variability of chick condition varied with Ring Ouzel breeding habitat.Clutch size was related to variation in territory habitat, broadly increasing with territory grass, sedge and rush cover. The best-supported models for within-brood variability of chick condition included fledgling number and territory habitat, with chick condition broadly becoming more variable with territory bracken cover. Relationships between breeding habitat and brood size, fledgling number or mean chick condition were not supported by the data, although statistical power was low.Conclusion Breeding habitat may be a driver of demographic rates of Ring Ouzel, with the effects of poor habitat being passed on indirectly through chick condition. The population-level importance of these effects is unclear, but this study highlights a possible link between recent observed habitat changes and first-year survival, the demographic parameter contributing most to variation in population growth rate in UK Ring Ouzels.Capsule Territory habitat influenced clutch size and within-brood variability of chick condition in Ring Ouzel Turdus torquatus.Aims To assess the relationship of Ring Ouzel productivity and chick condition with territory habitat, in order to improve understanding of the importance of breeding habitat for population change.Methods Productivity and chick condition were recorded for Ring Ouzel pairs in a small area of upland Scotland and these were related to vegetation and physical characteristics for all breeding territories using General Linear Models.Results We found that clutch size and variability of chick condition varied with Ring Ouzel breeding habitat.Clutch size was related to variation in territory habitat, broadly increasing with territory grass, sedge and rush cover. The best-supported models for within-brood variability of chick condition included fledgling number and territory habitat, with chick condition broadly becoming more variable with territory bracken cover. Relationships between breeding habitat and brood size, fledgling number or mean chick condition were not supported by the data, although statistical power was low.Conclusion Breeding habitat may be a driver of demographic rates of Ring Ouzel, with the effects of poor habitat being passed on indirectly through chick condition. The population-level importance of these effects is unclear, but this study highlights a possible link between recent observed habitat changes and first-year survival, the demographic parameter contributing most to variation in population growth rate in UK Ring Ouzels. |
| URL: | http://dx.doi.org/10.1080/00063657.2014.905514 |
| Short Title: | Bird Study |
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