8. Bird surveys
Once per month we surveyed bird species on all plots. Plots were initially surveyed for 3 hours/plot, beginning 15 minutes after
sunrise, this was reduced to 2 hours per plot in June 2000 due to the addition of plots 7 and 8. The survey order was changed
each day and each month to avoid time-activity biases. All species and number of individuals, on and within 5 m of the
plot were recorded. The vegetation or perch they were using was also recorded.