(information as at 13th December
2006)
The
national Atlas Working Group, and locally the HOS Atlas Steering
Group, have now agreed the basics for the Atlas field methodology. The
approach gives broadly similar methods in summer and winter and has a
good balance of methods for different levels of involvement and skill.
There are still some important areas of development but below are some
of the key points, beginning with a reminder of what the Atlas aims to
do and what the fieldwork aims to provide.
Aims of the HOS Atlas
project
-
To produce dot
distribution maps showing in which tetrads (2-km squares) each
species winters or breeds. (10-km squares for the national project)
-
To produce maps
showing broad patterns across Hampshire of relative abundance during
winter and the breeding season. (Britain & Ireland nationally)
-
To measure changes in
distribution and abundance patterns since earlier Atlases.
To
fulfil these aims, Atlas fieldwork in Hampshire must provide:
Seasons
Winter = beginning of November to end of February; four winters,
2007/08 to 2010/11.
Breeding Season = beginning of April to end of July; four seasons,
2008 to 2011.
General principles for
both seasons
-
Fieldwork will
comprise ‘Roving Visits’ and ‘Timed Tetrad Visits’ –
the two together providing the total species list and evidence of
breeding, and the latter providing the essential abundance data.
-
Both types of visits
are equally important, but in Hampshire we will concentrate
initially on the ‘Timed Tetrad Visits’ as the minimum level
of coverage for each and every tetrad.
-
Roving Visits
will be free-format – simply providing records of species with the
aim of amassing comprehensive species lists for each tetrad (or
10-km square nationally). Such records might be a result of a
day’s birding through a number of tetrads, or perhaps dedicated
searches of the habitat in one or two tetrads for hitherto missed
species.
-
Timed Tetrad Visits
are more structured:
-
Each Timed Tetrad
Visit in Hampshire will be for two hours, during which
individuals of each species seen and heard will be counted.
Observers can of course continue after the two hours on a
Roving Visit basis, to search for species not already
encountered or to seek further evidence of breeding.
-
In a season (winter
or summer) there will be two such visits, one early and one
late. For winter this means one visit in Nov-Dec and one in
Jan-Feb. For the breeding season this means one in Apr-May and one
in Jun-Jul. A tetrad need only be surveyed in one summer and
one winter.
-
The aim will be for
all of Hampshire’s 1000+ tetrads to receive Timed Tetrad
Visits..
Evidence of breeding
The
3-level system for evidence of breeding will be used (e.g. singing;
bird with food; nest with eggs). This information will be sought from
Timed Tetrad Visits and Roving Records. Evidence of
breeding is also being built into BirdTrack as an optional field to
facilitate further data capture.
Tetrad-scale population
estimates
Details are still to be finalised, but it’s likely that observers will
also be asked to provide a rough estimate (possibly in a category of
abundance) of the tetrad’s population of each species they encountered
during their timed visit. This will be easier for some species and
some tetrads than for others. For instance, an observer visiting a
tetrad that has only one lake, may easily be able to give an estimate
of the Coot population in that tetrad. But estimating the number of
Skylarks in a tetrad might require some judgement (e.g. I saw 15
skylarks during my visit, and maybe covered a quarter of the tetrad,
so I reckon there are around 60). Further guidance and full
instructions will be provided.
Next steps
Now
that the broad shape of the field methods are fixed, BTO staff are
working on draft instructions and forms, and on the development of
online systems. We are anticipating that in Hampshire we will be able
to use the national recording forms, and the national instructions
with minimal modification (possibly just an addendum note). We also
expect to use the national online systems and applications that will
be used by organisers and observers to input and manage their data.
Meanwhile, we’re also busy organising coverage for the Timed Tetrad
Visits. Please take a look at the “How can I help” section of the
Atlas information on this website.
Chairman, HOS Scientific
Committee & Atlas Steering Group
