1. Record diversity BTO Garden Bird Feeding Survey 1
This graph is from the BTO’s Garden Bird Feeding Survey – a small scale project which looks at the use of bird food in gardens during the winter months.
During the 1970s, an average garden feeding station supported around 16 species of birds during winter. Now, however, this figure is well over 20 species.
The big questions: (i) Why? (ii) Is this good news?
Is this upward trend a result of bird foods/feeders improving, with more species simply taking advantage?
Is this trend because garden vegetation across much of suburbia has matured, thereby providing better habitat for more species?
Could this upward trend also mean that food for birds in the wider countryside is running low, forcing birds to turn to our hand-outs?
BTO Garden Bird Feeding Survey 1

2. Why am I here? Jill Pakenham 2
Good example is the Reed Bunting. Traditionally a farmland species, this bird has been cropping up more and more in gardens of late. Is this because it is finding things in gardens more to its liking, or is it because agricultural intensification (e.g. shift to autumn sowing, use of herbicides) is resulting in lower food availability in the countryside?
Jill Pakenham 2

3. Why am I here? Jill Pakenham 3
In many ways, the same also applies to the Goldfinch. This bird has been coming into gardens increasingly, and there is some evidence that as food runs low in the countryside Goldfinches shift from farmland to gardens…
Jill Pakenham 3

4. Goldfinch on farmland BTO Winter Walks 4
Here, a different BTO survey (BTO Winter Walks) demonstrates that the percentage of farmland sites where Goldfinches are found declines from November through February.
This could be because:
Increased mortality through winter?
Partial migration – many Goldfinches migrate to the continent in autumn?
Movement of Goldfinches from farmland into other habitats..?...
BTO Winter Walks 4

5. Goldfinch in gardens BTO Garden BirdWatch 5
…Garden BirdWatch data show that from November through February as the percentage of farmland sites on which Goldfinch occur declines, the percentage of gardens in which Goldfinch occur increases. This suggests that Goldfinches move into gardens during late winter when natural food resources in the wider countryside are depleted.
So, a question to ask yourself when enjoying your garden birds is ‘why are these birds here’? Through the BTO’s surveys, this question can be explored.
BTO Garden BirdWatch 5