29 July 2013

Spring weather bad news for Barn Owls

Over the summer we've been hearing some pretty depressing stories of how badly Barn Owls seem to be doing this year. The poor spring weather appears to have been bad for small rodents, the staple diet of most Barn Owls. Birds in poor condition may choose to skip breeding for the year and others starting breeding may abandon attempts part way through due to lack of food.

Food shortages can severely limit breeding performance
(Jill Pakenham)

Below are a few extracts from emails and Forum posts we've received, giving a flavour of the season from around the country.

Lincolnshire (Alan Ball and Bob Sheppard)

"Only about 60 pairs have been found breeding so far, where we would have normally expected around 200 pairs by now. Only 55 chicks have been ringed compared with 160 by this time last year. Several pairs are just starting to nest, so there's hope that things may improve, though birds remain absent from many traditional sites

Kestrels are also down with nearly 150 chicks ringed against nearly 200 last year. Tawny Owl chicks numbered only a third of last years numbers, but Little Owl site occupancy was good with our best year ever of 70 pairs."

North West Norfolk (Phil Littler and John Middleton)

"I've just got in from checking 30+ boxes, and have got just three on eggs. Three sites had dead owls in or under the boxes, and just five sites held any Owls at all. A thoroughly depressing day. I thought it would be bad when my Tawny Owl totals showed a 75% drop on last year, but not as bad as this."

"Well now I have checked over 200 sites and only 34 pairs are breeding, 14 sites have pairs that are not yet breeding and 25 sites had single adults. So far I have only ringed 34 chicks although I do have to re visit 16 sites because chicks were too small or the female was incubating eggs. I still have a number of sites still to check but don’t expect it will get better. Can’t see the Group this year ringing anything like the 391 chicks we ringed in 2012!"

Wiltshire (Alison Rymell)

"I checked 11 boxes in the Deverill Valley in mid-June: none had either eggs or young. Only one had a pair of owls and one had a single owl. Another had a dead owl [long dead]. Four had Stock Doves, three with eggs. Of the 11 boxes, six normally have successful broods. Last year four of the six lost their first broods, three laid a second clutch and reared the young successfully."

Cornwall (Mark Grantham)

"We still haven't done all our boxes, but so far the season seems to be 5-6 weeks later than previous years:
  • 7 sites occupied last year but not this year (and one unoccupied for the first time in 17 years!)
  • 3 sites occupied but not breeding
  • 6 sites with chicks, but all small broods
  • 3 failed at the egg stage
  • 7 not occupied this year or last year
  • 2 sites occupied but outcome still unknown"
One of the non-breeding pairs from a Cornish nest box (Mark Grantham)

25 July 2013

The countdown is on!

At this time of year, ringers and nest recorders are very busy with their projects and study sites. The data collected forms an invaluable insight into the productivity and distribution of birds all over the UK and Ireland. The online ringing section of the BTO website shows a great selection of recoveries generated from all the ringing that has occurred since 1909 but news of another fantastic resource will soon be available.

Between 2007 and 2011 tens of thousands of volunteer birdwatchers, ringers and nest recorders recorded in the winter and breeding seasons for Bird Atlas 2007-11. All areas and habitats were covered, from villages, towns, farmland and fens to remote mountains and far-flung islands. This stock-take of our birds is already revealing fascinating changes in the status of our birds and will shape the direction of conservation action over the coming decades.

Breeding distribution of Spotted Flycatcher during the breeding-seasons of 2008 to 2011

The Bird Atlas will soon be available, but our special pre-publication offer ends at midnight on the 31st July! If you order before this and you'll only pay £45 (plus p&p), saving 35% on the RRP. After this, the book will be priced at £70. Be one of the first to receive Bird Atlas 2007-11, the most important British and Irish Bird Book for decades. It offers the most complete and comprehensive overview of bird distribution and change. With over 1,300 maps for nearly 300 species in one hardback volume, it's compiled from data collected by over 40,000 volunteer surveyors.

Order your copy and view sample pages here.

Spotted Flycatcher - Graham Austin

An interesting example of what can be learned can be seen with the BTO bird of the month - Spotted Flycatcher. Click here to learn more about its breeding distribution.

17 July 2013

Shelduck shot in Belarus an unexpected first

Earlier in the summer we belatedly received details of a ringed Shelduck from the Belarus Ringing Scheme, and subsequent communication with Highland Ringing Group highlighted that this was rather unusual and very far east. GF78567 was ringed near Castle Stuart, Inverness, in January 2003 and reported shot in autumn 2009 in the Minsk region of Belarus, but the details have only recently been processed. This is by far the furthest east recovery of a Shelduck to/from the UK (see map below from the Online Ringing Report): a British-ringed bird has previously made it to western Poland and birds ringed in in Finland, Estonia and Lithuania have been found in the UK.

Map of Shelduck recoveries to/from the UK
In fact, Shelduck is a pretty unusual bird in Belarus anyway (see the below map from avibirds),so this record is even more surprising.

Thanks to Bob Swann for bringing this to our attention.

05 July 2013

Sad demise of a pioneering Honey Buzzard

On 14th June, a flash of green ring amongst the seaweed on Par beach in Cornwall lead to the discovery of the unfortunate remains of a bird of prey. This was in fact the sad end to the pioneering Honey Buzzard GN18656.

GN18656 (Green 4) was originally ringed as a chick (from a brood of two) in Shropshire by Jerry Lewis in July 2000. In 2006, a fieldworker in South Wales noticed a female Honey Buzzard with a colour ring and after some patient observation managed to confirm that this was Green 4. Her distinctive plumage also indicated that she had been in the same area for both the 2004 and 2005 breeding seasons

Green 4 at the nest in South Wales

Amazingly, her mate was also colour-ringed; originally ringed as a chick in North Wales in 2003. A note on this event was published in British Birds (Roberts & Lewis 2008, British-reared Honey-buzzard return to breed in the UK, BB 101, 203-206) and at the time of this sighting she set a new UK longevity record, which was stretched further when she was found breeding nearby (using nest cams) in August 2011 and July 2012. This was a very sad end for such a pioneering bird, but some remarkable information did come from her 13-year life, only possible through the foresight of colour ringing the chicks.

There are very few recoveries of Honey Buzzard, so colour-ringing of birds is vital to increase our knowledge of their movements. The Online Ringing Report shows that British-ringed birds have been found in France (2), Ghana (2) and Guinea and birds from Germany, Sweden and The Netherlands have been found here.

Thanks to Jerry Lewis for the information and the photo, also to Karen Ironside for reporting and photographing the bird in the first place!