Hertfordshire News and Comment

Bird Atlas 2007-11 and the Hertfordshire Bird Atlas

It’s hard to believe, but it really is almost 20 years since we last embarked on a national and countywide bird distribution atlas, and the original BTO Winter Atlas is now 25 years old. Starting in November 2007, fieldwork for Bird Atlas 2007-11 will begin. This time we will be collecting information for both the winter and breeding seasons in a single project which will run for four years. The winter season will span the months of November to February and the breeding season will be considered to run from April to July, although breeding records outside of that period are also important.

The aim of the atlas will be to assess the distributions and relative abundance of birds in each of the seasons. Fieldwork will be a combination of two methods. The Timed Tetrad Visits will involve counting birds for two hours, with the option to extend beyond that, on two occasions in each tetrad in one winter and one breeding season. The challenge will be to devise a route that covers all habitats in the tetrad during the two hours. These visits will contribute to the distribution maps, but also allow abundance estimates to be calculated. The Roving Records element is aimed at building up a definitive species list for each 10-km square, adding to the species found during the timed counts. This will be used primarily to generate the distribution maps.

As was done alongside the two previous national breeding atlases, the Herts Bird Club is running a tetrad-based atlas project in parallel. We will be following the same methods, but building species lists at the tetrad (2-km square) level. This will be our first county-wide winter distribution survey at this scale.

Four of the bird clubs in our neighbouring counties (Buckinghamshire, Bedfordshire, Cambridgeshire and Greater London) are also embarking on tetrad atlases projects over the same period, and where there are overlaps of interest we are committed to exchanging data.

At the time of the last atlas, the internet was in its infancy but the Herts Bird Club did enter the data onto a computer database and shared the gradually evolving maps at indoor meetings. With the advances on technology we can now do a much better job of providing feedback, more quickly and in a more interactive and visually appealing form. To this end the results from the 1967-72 and 1988-92 county tetrad atlases and the 10km scale results from the 1981-84 national Winter Atlas are already online at the Hertfordshire Bird Atlas website.

This website will be used to keep everyone informed of progress and display the accumulating results during the period of the new atlas project. It will be possible to enter the results of your fieldwork online, at the Bird Atlas 2007-11 website. Data from other surveys, such as the RSPB/BTO/JNCC Breeding Bird Survey and records submitted to BirdTrack will also feed into the atlas.

This is a project where everyone can help to map the distribution of Hertfordshire’s birds, and help to quantify changes over the past 20 years, so if you have not done so already please contact your local 10km square co-ordinator (see Contacts) or myself .

Chris Dee (BTO Regional Representative and Hertfordshire Bird Atlas Organiser)
26 Broadleaf Avenue, Bishop’s Stortford, Herts CM23 4JY