AVIS-IBIS

Birds of Indian Subcontinent

Crop use by introduced bird species in winter in relation to crop structure and seed resources: Capsule Most species preferred to forage in grassland where seed resources were more abundant and the vegetation was uniform in height but heterogeneous in den

Publication Type:Journal Article
Year of Publication:2007
Authors:Macleod, CJ, Till, A
Journal:Bird Study
Volume:54
Date Published:2007
ISBN Number:0006-3657
Keywords:Alauda, Alauda arvensis, Alaudidae, Carduelis, Carduelis carduelis, Citrinella, Emberiza, Emberiza citrinella, Emberizidae, Fringillidae, Merula, Passer, Passer domesticus, Passeridae, Sturnidae, Sturnus, Sturnus vulgaris, Turdidae, Turdus, Turdus maximus, Turdus merula
Abstract:Aim To determine the influence of crop composition and structure, and seed food resources on the distribution of introduced bird species on New Zealand farmland in winter. Methods Birds were counted on 90 ha of mixed cropping farmland during mid- and late-winter periods, 2004. The presence or absence of six introduced species (Blackbird Turdus merula, Skylark Alauda arvensis, House Sparrow Passer domesticus, Goldfinch Carduelis carduelis, Yellowhammer Emberiza citrinella and Starling Sturnus vulgaris) in fields was investigated in relation to crop composition and structure and seed abundance. Results Species?habitat associations varied over time and between species. Blackbird, House Sparrow, Yellowhammer and Starling were associated more frequently with grassland than arable crops during at least one survey. Seed abundance was a significant predictor of the occurrence of all species except House Sparrow, while crop structure was a predictor of only Goldfinch, Yellowhammer and Starling occurrence. Conclusion During the winter, the distribution of six introduced bird species in the lowland cropping area was related to habitat composition, vegetation structure, and seed food resources. The preference for grassland habitats was probably determined by the vegetation structure and seed resources in these areas. The trend for increased use of supplementary animal feed in livestock farming in New Zealand may help sustain introduced bird populations. A larger-scale study is needed to investigate the generality of the species?habitat associations detected in this study at the landscape scale.Aim To determine the influence of crop composition and structure, and seed food resources on the distribution of introduced bird species on New Zealand farmland in winter. Methods Birds were counted on 90 ha of mixed cropping farmland during mid- and late-winter periods, 2004. The presence or absence of six introduced species (Blackbird Turdus merula, Skylark Alauda arvensis, House Sparrow Passer domesticus, Goldfinch Carduelis carduelis, Yellowhammer Emberiza citrinella and Starling Sturnus vulgaris) in fields was investigated in relation to crop composition and structure and seed abundance. Results Species?habitat associations varied over time and between species. Blackbird, House Sparrow, Yellowhammer and Starling were associated more frequently with grassland than arable crops during at least one survey. Seed abundance was a significant predictor of the occurrence of all species except House Sparrow, while crop structure was a predictor of only Goldfinch, Yellowhammer and Starling occurrence. Conclusion During the winter, the distribution of six introduced bird species in the lowland cropping area was related to habitat composition, vegetation structure, and seed food resources. The preference for grassland habitats was probably determined by the vegetation structure and seed resources in these areas. The trend for increased use of supplementary animal feed in livestock farming in New Zealand may help sustain introduced bird populations. A larger-scale study is needed to investigate the generality of the species?habitat associations detected in this study at the landscape scale.
URL:http://www.tandfonline.com/doi/abs/10.1080/00063650709461459
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith