Atlases
These two Atlases have now been published:


Have a look at the results of all the BTO national Atlases: Mapstore
The areas covered by the BTO representatives in North Wales (based on a map on the BTO website (bto.org).

DA Dave Anning
AB Anne Brenchley
GG Geoff Gibbs
IH Ian Hawkins
MaO Mel ab Owain
Local, or regional, atlases usually use the 'tetrad' as the recording unit. A tetrad is a square, 2 km x 2 km. The map, below, shows the tetrad SJ26N, which means that its western boundary is the easting 24 and the bottom boundary is northing 66 within the 100 km square SJ, so the tetrad includes the 1 km squares: SJ2466, SJ2467, SJ2566 and SJ2567.


Within each 10 km square there are 25 tetrads.
The CBRG and COS welcome receiving breeding season records with breeding codes, as used in the Atlas fieldwork, and listed below:
Possible breeding
01 H - Observed in suitable Habitat
02 S - Singing male
Probable breeding
03 P- Pair in suitable nesting habitat
04 T - Permanent Territory (defended for at least one week)
05 D - Courtship and Display
06 N - Visiting a probable Nest site
07 A - Agitated behaviour
08 I - Brood patch of Incubating bird (from bird in the hand)
09 B - Nest Building or excavating a nest hole
Confirmed breeding
10 DD - Distraction Display or injury feigning
11 UN - Used Nest or eggshells found from this season
12 FL- Recently FLedged young or downy young
13 ON - Adults entering or leaving nest site in circumstances indicating Occupied Nest
14 FF- Adult carrying Faecal sac or Food for young
15 NE - Nest containing Eggs
16 NY - Nest with Young seen or heard
Please enter these codes in the 'Activity' column in the spreadsheet or the relevant extra details form in BirdTrack.