Key Points
- Vegetation on commercial property varies a lot, and provides critical habitat for bird species of interest.
- All measures of the bird community are positively influenced by the presence of more native conifers, particularly old trees that are protected during development activities, and the presence of native shrubs.
- The bird community is negatively impacted by the presence of more non-native trees. Brown Creeper, Red-breasted Nuthatch, and Varied Thrush are among those species most impacted.
- Native bird species populations may be helped by greater provision of native conifer habitat, which is possible using currently existing developments as models and more robust tree protection.
- Property owner actions are central to urban vegetation & thus bird habitat.
Interested in how you can apply these ideas to your property, tree protection policy, etc.?
Research Summary
In cities, vegetation provides critical shelter, nesting, and foraging habitat for bird species of interest. Human actions---including development and landscaping choices---determine vegetation community composition and structure.
Thus, human actions impacting vegetation are critically important to bird conservation in cities. A better understanding of how bird communities are impacted by parcel-scale actions that alter vegetation communities can help guide policy and management best practices to improve matrix habitat quality and quantity.
Here, I examined how bird habitat use varies along a vegetation gradient created by different development and landscaping choices. Where previous research focused on public green space and private residential property, I expand this research to 20 commercial office developments in King County, Washington, USA selected using stratified random sampling.
I quantified the bird communities and observed feeding behavior on office developments, collected data on tree, shrub, and ground cover communities, and gathered information about neighborhood scale socio-economic and land cover variables.
I found that all measures of the bird community are positively influenced by the presence of more native conifers, particularly old trees that are protected during development activities, and the presence of native shrubs. The bird community is negatively impacted by the presence of more non-native trees. Brown Creeper, Red-breasted Nuthatch, and Varied Thrush are among those species most impacted.
In contrast to prior research, top-down neighborhood-scale variables did not explain variation in any measures of the bird community on office developments. Importantly, I found that birds are associated with the same habitat on office developments as observed elsewhere. Together, my findings suggest an important role for developers, land owners, landscape architects, and tree protection policy in bird conservation.
Thus, human actions impacting vegetation are critically important to bird conservation in cities. A better understanding of how bird communities are impacted by parcel-scale actions that alter vegetation communities can help guide policy and management best practices to improve matrix habitat quality and quantity.
Here, I examined how bird habitat use varies along a vegetation gradient created by different development and landscaping choices. Where previous research focused on public green space and private residential property, I expand this research to 20 commercial office developments in King County, Washington, USA selected using stratified random sampling.
I quantified the bird communities and observed feeding behavior on office developments, collected data on tree, shrub, and ground cover communities, and gathered information about neighborhood scale socio-economic and land cover variables.
I found that all measures of the bird community are positively influenced by the presence of more native conifers, particularly old trees that are protected during development activities, and the presence of native shrubs. The bird community is negatively impacted by the presence of more non-native trees. Brown Creeper, Red-breasted Nuthatch, and Varied Thrush are among those species most impacted.
In contrast to prior research, top-down neighborhood-scale variables did not explain variation in any measures of the bird community on office developments. Importantly, I found that birds are associated with the same habitat on office developments as observed elsewhere. Together, my findings suggest an important role for developers, land owners, landscape architects, and tree protection policy in bird conservation.