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Simple methods - get involved! Fieldwork will span 4 winters and 4 breeding seasons, starting in November 2007, during which we will cumulatively survey the whole of Britain and Ireland. To fulfil these objectives there are two complementary fieldwork methods which offer something for everyone. Roving Records - whatever you see, whenever, wherever
Timed Tetrad Visits - dedicated counts in specified tetradsTimed Tetrad Visits (TTVs) are principally concerned with discovering the broad patterns of relative abundance. Basically a TTV involves walking around a tetrad, birdwatching for 1 or 2 hours and recording everything you see and hear.
Timed Tetrad Visit field methods These brief instructions apply to either winter or breeding season. Ideally the same tetrad would be done in both seasons. Please download comprehensive instructions here. You need to make two visits in a season, one early and one late. In winter this means the first visit in November/December and the second in January/February. In the breeding season this means the first in April/May and the second in June/July. Once you have made two visits in the winter and two visits in the breeding season, then that tetrad is done. A tetrad should not be covered in all four years of the Atlas. Each visit must last a minimum of 1 hour, or optionally 2 hours. Whether you spend 1 hour or 2 hours, during this timed part of the visit you should aim to survey all the major habitat types present in the tetrad and count all the adults of all species you see or hear. Counts from the first hour and second hour should be kept seperate. Please try to exclude juveniles (birds of the year) where possible, although this can become more difficult as the breeding season progresses. The term 'adults' includes all birds in immature plumage that you may encounter eg gulls, Cormorants, raptors. You can briefly 'stop the clock' if you encounter large flocks or especially dense concentrations of birds that slow your progress. Record any evidence of breeding you notice whilst surveying. Remember the code 'T' (territorial birds) may be applied to several birds singing against each other on one day. At the end of your 1 or 2 hours you can opt to continue listing (i.e. just ticking off) additional species, or returning to particular areas to search for missed species or to try and confirm breeding. You can change the route around your tetrad between the early visit and the late visit. After your two visits you
can optionally produce your own estimate of how
many individuals (adults) of each species was present in the whole
tetrad. This 'Tetrad Population Estimate' refers
to the number of birds you think may be present in the tetrad and
not the number you think may be breeding. So bearing in mind how
much of the square you visited you might be able to very approximately
extrapolate the numbers you encountered on your route to the number
in the whole tetrad. We are only looking for very approximate numbers,
to the nearest 1 for numbers less than 10, to the nearest 10 for
numbers less than 100, to the nearest 100 for numbers less than
1000 etc. For some species and habitats this will be very easy but
for others much more difficult. If you visited the only lake in
the square and saw 6 Tufted Ducks your tetrad estimate will be just
6. If on the other hand you reckon you visited half of the woodland
and encountered 14 Blue Tits, your extrapolated tetrad estimate
might be 30. Though these numbers are by definition pretty crude,
other studies have found them to be very useful when taken with
everyone else's across the whole country. But they are optional,
so if you don't feel confident giving them don't worry.
A more comprehensive document about Tetrad Population Estimates is available here. |
Tetrads
are 2km × 2km squares and labelled A to Z within each 10-km
square (see image, right). TTVs do not aim to produce a
complete species list for the tetrad, but a sample of what one can
find during a pair of visits in winter and/or summer. We aim to
cumulatively cover at least 8 tetrads in every 10-km square in Britain
and Ireland during winter and summer. You can take on one or as
many tetrads as you wish. This is a great opportunity to visit those
hidden corners of the landscape and find new birds. If you are interested
in taking on a tetrad (or more..) please contact your Atlas Regional
Organiser (
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