Avon BTO

Thursday, November 08, 2007

Atlas-The First week

The Atlas has had an amazing start, both nationally and locally. Nationally they have had 770 tetrads visited, and 1500 on line participants, who have sent in records of over 1 million birds. If you go to the results section of the website you can see maps of a number of species.
In the Bristol region we have 231 of 399 tetrads covered, and effectively total coverage of ST36 and ST58, which is almost 60%. 23 tetrads have received their first visit for the winter, which is good going. Several people have said that numbers are very low, and are waiting until things get a bit more interesting and the leaves are off the trees, but it has been very nice being out in clear calm weather. It is a good idea to get the first visit done in November as December often gets busy, there is very little light, and the weather can be nasty. If, having done one tetrad you realise how easy it is and want to volunteer for another please do so-I have set the target of coveraing all tetrads in two years, but it would be nice to almost complete it in one! And dont forget in many regions of the country each observer is responsible for a whole ten km square, and covering the minmum eight tetrads in it himself.
I dont yet have access to the records of other observers- that is being worked on, but it is clear from my own records that the number of Blue Tits and Great Tits is well down on recent winters. In the last winter Atlas, around 1980, over three years there were 3000 hours of observation, and I calculated the rate at which each species was seen overall which gives a good oveall feel for observed density. Blue Tits were observed at an average of 5.4 an hour and Great Tits at 3.0 per hour. This winter over twelve hours of observation I have had rates of 3.3 and 0.8 respectively. This is the consequence of the terrible breeding season which the CES figures just released have revealed.


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