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Gardens as a habitat for birds There are virtually no bird species within Britain & Ireland that occur only within gardens, to the exclusion of all other habitat types, although one might argue that nesting Swifts and House Martins are limited to human habitats. However, gardens and other built-up habitats have been shown to support a large component of the populations of a number of breeding species, e.g. Blackbird (33%), Starling (54%), Greenfinch (38%) and House Sparrow (62%). The BTO Garden Nesting Survey, established by John Tully and Richard Bland and carried out by BTO/CJ Garden BirdWatchers, has emphasized that the size of breeding bird populations within in gardens may be substantially greater than previously thought. For some species, such as Blackbird, populations exist at higher densities in gardens and other built-up habitats than in farmland, and they may even be more productive. For other species, garden populations have been shown to be less productive than their farmland or woodland counterparts. All gardens are not equal in terms of their suitability for different bird species. The average Garden BirdWatch reporting rate for Robins differs between the three classes of garden used in the project. The reporting rate is consistently highest in rural gardens and lowest in urban ones (see graph). The reverse pattern can be seen for House Sparrow (see graph).
The other thing to note, and which is particularly evident in the Robin graph, is that the use of gardens may also vary with season. In the case of the Robin, the summer fall in reporting rate suggests that while many gardens may hold Robins in the winter, gardens may not have the resources needed by a breeding pair.
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Garden
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