Cambridgeshire Bird Club:
Screaming Swift Survey 2008Introduction
During 2002 and 2006 the Club,
together with the City
Greenways
We would like Cambridgeshire Bird
Club members to continue to send in precise details
of new colonies, across the county, as well as confirming the continued
existence of previously known colonies.
There is a strong suspicion that
Swifts are declining across
the country. The main objective evidence for this is the BTO/JNCC/RSPB
Breeding Bird Survey (BBS) which
shows a national decline of 26% between 1994 and 2006, but here, in the
east of
England, a 63% decline between 1999 and 2006, which, if true, is
alarming.
The BBS results for Swift look no
less consistent than many
other birds, judging from their confidence limits, but there is a
suspicion
that it may not be giving a true picture, as the BBS methodology is not
a direct measurement of local breeding populations, and because of
the
unique
and differing life-style of Swifts.
Therefore
we would like to explore
a survey methodology based upon monitoring Swifts at their breeding
colonies,
to get a more direct measure of local breeding population levels.
One
characteristic behaviour of Swifts
is to form low-level screaming parties. This is part of their breeding
display near a colony.
First,
the identification of
locations where screaming parties are seen is the foundation of the
survey. Screaming
parties comprise
local breeders as well as birds from a wider catchment. Later in the
season,
prospecting non-breeders are also involved.
Second,
members are asked to carry
out 5-minute surveys, according to the instructions provided, at a
number of
recognised colony locations across the county.
At
this stage, there are a number
of things that we do not know, so we would like to capture more data
from fewer
locations as a basis for refining the survey in future years. We need
to firm
up recommendations on dates, times of day and time spent at a colony
sufficient
to get a handle on the population in the catchment that surrounds the
colony.
Known
points for observing
colonies are recorded on this Google Map
Click
on any symbol to find the
colony identifier.
Links:
5-minute-survey-form.xls ( printable PDF )
Send
colony locations and 5 minute
survey forms to Dick
Newell