This takes us to the heart of
COGland, and into the territory of Philip and Martin. Below is a slide
from my off-the-shelf talk on Canberra birds. The percentages refer
to SITES where the species has been recorded at all in a full year (not
abundance). The first column is derived from Philip’s analysis of
the first 21 GBS years, treating those years as a block. Then, sparrow
and starling were firmly entrenched in the Top Ten GBS birds. In the more
recent 2 years shown, the sparrow was not recorded at all in 20% of the
(3-hectare) sites. I need to update the graphic, but the trend
continues. Martin tells me that in 06-07 only 78.6% of sites had sparrows.
Given that that is over a full year, it also suggests that they don’t
move around much.
