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Hi John,
After a peak in April, mid May is late for them and
most likely is the time that the last few are leaving and the behaviour for this
time is typical. There are none in June or July.
This from the GBS Report. - Which, by the way, is a
much easier way of seeing or reading in one place, trends, by month, of what the
recorded relative abundance over a compiled 21 year period, of birds has
been, than by scrolling through coded text in each of many or maybe only
one of the Annual Bird Reports. A point that curiously (!?) was not mentioned at
Wednesday night's COG meeting. And likewise for the COG Bird Atlas,
although that only shows recording rate.
85 species is getting pretty good but there is
still surely scope for a lot more. Figure 25 of the GBS Report shows the trend
for number of species recorded at relative to each site's number of observer
weeks, which along with habitat and observer skill and activity are the main
factors. Figure 16 shows the species accumulation curves for the sites
surveyed for 21 years, all of which were still getting new ones.
Philip
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