In 2007 Wiltshire Ornithological Society (WOS) published a comprehensive county avifauna (Ferguson-Lees,I J et al “Birds of Wiltshire”) which included maps showing, where applicable, the summer distribution and breeding status, summer abundance and winter abundance of all the bird species regularly occurring in the county. The summer maps were based on fieldwork carried out by some 160 volunteer observers who, between April 1995 and July 2000, made timed visits during the breeding season to every one of the 915 tetrads (2x2km squares of the National Grid) that lie wholly or mostly within the Wiltshire ceremonial county. To produce the winter abundance maps, timed visits were made in the two winters of 1998-99 and 1999-2000 to a structured random selection of slightly under 50% of the tetrads.

Also in 2007 the British Trust for Ornithology (BTO), in collaboration with BirdWatch Ireland and the Scottish Ornithologists Club, began work on a new bird atlas of Britain and Ireland. They appealed for volunteers to carry out the fieldwork and in return offered local bird clubs the opportunity to use the electronic data recording system that had been set up for the national atlas to record and manipulate data for any county level atlases that the clubs might wish to produce. After some initial hesitation, given that Birds of Wiltshire had only just been published, WOS decided to take advantage of this opportunity to produce an up-dated county tetrad atlas, covering both wintering and breeding birds. Between November 2007 and July 2012 timed tetrad visits were made to all 915 Wiltshire tetrads in both winter and the breeding season. In addition recent advances in information technology made it possible to gather in far more casual records than had been possible a decade previously: around 600 contributors between them posted an estimated 300,000 Wiltshire records.

How to use this website

This website makes available the results of all this fieldwork. Using the menu on the left, you can do the following:

a.) Show a list of all species recorded during atlas fieldwork in the county in 1995-2000 or 2007-2012 in the winter or  breeding seasons

 - select the appropriate link in the Atlas species lists menu to display a list of species recorded in the corresponding atlas period and season, in taxonomic order. Use the links in the Species sequence menu to change the species order to alphabetical or frequency of occurrence.

b.) Show a map showing the distribution of any species on any of the lists

 - select the chosen species on the list to display a map; in the case of the breeding distribution map, different sized dots show the breeding status of the species in each tetrad; in the case of the abundance maps, the different colour shades indicate the relative abundance of the species; the winter distribution maps use dots of uniform size to indicate the presence of the species.

c.) Display the grid reference and name of any tetrad, and either the breeding status or abundance count of the species to which the map refers

 - hover the cursor over the tetrad to show this information.

d.) Display details of all the species found in any tetrad

 - click on any tetrad on any map to bring up a full species list showing the species recorded in that tetrad, for the same period and season as the map; use the links in the left column to view tetrad species list for other periods and seasons.

e). Display species list in an adjacent tetrad for comparison

 - click on the relevant tetrad in the block of nine tetrads in the Adjacent tetrads menu.