Background

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.

Usage guide

These pages provide summary maps of species richness for each of the atlas periods and breeding evidence confirmation rate for the breeding season atlases. 

To view a richness map, select a 'Map type' of Species Richness and the atlas period of interest and click the 'Go' button. 

To view a breeding evidence map, select a 'Map type' of Breeding Confirmation and the atlas period of interest and click the 'Go' button.