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Thursday 29 November 2012

NRS Preliminary results

The BTO have now released the preliminary results of this year’s Nest Record Scheme which can be found here -http://www.bto.org/volunteer-surveys/nrs/results/2012-preliminary-nrs-results
So, how do my own 2012 records compare with the national picture.
Nationally, April and June saw record rainfall, April having four times the average and June having twice the average. Here at Stithians April saw 157.7mm of rainfall and June saw 142.5mm with another 112mm in July all topped off with a further 137.2mm in August. Pretty bleak 
 
On migration long distance migrants battled storms in the Sahara and across Europe only to be greeted with cold and wet weather on their breeding grounds.
Having been a nest recorder for only 3 years and with 2012 being my first year where nest recording has been the priority i dont have sufficient records to compare fve year averages as the BTO have done. Across the country fledglings for Blue Tits and Great Tits were significantly below average, Great Tit’s having their second worse season on record, a statistic reflected in my own records. My nest boxes fared as such15 boxes were occupied (7 Great Tit, 8 Blue Tit). This was a marked difference to the boxes from 2011 when the same number of occupied boxes were spread between 2 Great Tit and 13 Blue Tit. Of the 7 Great Tit records 32 eggs were laid with only 8 hatching and from this 8 only 5 fledged. The success rate from egg to fledging was a mere 15%. Blue Tit's on the other hand with their 8 records produced 54 eggs of which 42 hatched and 32 fledged giving a success rate of 59%. One box was found to contain 8 dead chicks that were ready to fledge as more bad weather took it's toll on food supplies and chilling chicks overnight
On the national scale and compared to the average for the last five years Great Tit fledgling success was down 17.7%, Blue Tit down 12.8% with Chaffinch being the lowest level since records began in 1965 down a massive 57.6%

From the three Chaffinch nests i found, one was predated/deserted, one fledged two and one fledged four so six were fledged from the three nest records.

Hopefully as my skills develop i will be able to produce a more comprehensive picture of nesting passerines at Stithians.