Bellbirds (and other bush birds) in the Canterbury landscape – motivation for our studies
We know that large areas of mature native bush provide suitable breeding and feeding habitat for our bush birds. But the suitability of small bush fragments, exotic plantations, urban vegetation and wooded areas on farms is much more complicated to assess. In Canterbury a great deal of our lowland vegetation is fragmented and mixed, particularly in and near urban areas. The satellite image below shows small patches of wooded vegetation in dark green, for the area of Canterbury south and west of Christchurch.
Landsat 7 image, 27 February 2000
As we try to care for and restore birdlife and habitats in the Christchurch area, it is important for us to understand factors like:
- Where do our bird species nest, and where do they feed – are they making use of just a single type of habitat all year, or do they move around widely and rely on a wide variety of plants and areas?
- What are the characteristics of suitable breeding sites, in terms of a safe and stable place to build a nest, proximity of sufficient food sources, and preference for “social” interaction or grouping?
- How are nesting birds affected by predators, in urban, rural and near-urban bush reserve environments?
- What food resources are needed to see the birds through winter?
These questions require us to determine what types of habitats and what types of plants are being used during different times of the year. They require us to find out how far the bird species can travel from food source to food source, and whether they are willing to travel across open country and urban areas, or whether they confine themselves to continuous canopy bush. We need to find out how big a patch of wooded vegetation is required by a pair of breeding birds, and what food resources are needed during this critical period.
We want our research to be useful in the management and restoration of bird habitat in the Canterbury region. In particular, we aim to make it possible to predict the effect on bellbird populations of restoring or removing wooded areas, and to provide input on habitat restoration.
We have made a start on answering some of the questions with four interlinked research projects:
- Understanding bellbird breeding habitat in the Port Hills
- Colour-banding of Port Hills bellbirds to determine movements and range
- Working with bellbird observation data contributed by the public to build up a picture of bellbird habitat use throughout Mid- to North Canterbury
- Song recording for
field identification