Feeling a bit broody

With winter loosening its grip on the British countryside our bird life is starting to look forward to spring! Here at BTO HQ, we are winding up to a busy nesting season and are searching the hedgerows and bushes for nests.


Egyptian Geese - photo by Rachael Barber

So far this year we have found nests of Coot, Egyptian Geese, Mallard, Robin, Blackbird, Song Thrush, Long-tailed Tit, Wren, Collared Dove and Dunnock, with more species being added every day. Each nest will be fully recorded for the BTO Nest Record Scheme (NRS) with nest finders following the NRS code of conduct.


Mallard nest with nine eggs - photo by Lee Barber

Robin nest - photo by Rachael Barber

Several BTO staff and volunteers record nests around Thetford, Norfolk, but how do we avoid recording the same nest? The answer is that we share a Google Map between us, with colours and shapes used to denote the progress of each nest and a note included of who found the nest. After a day of 'nesting' we update the map with our exciting discoveries and this informs everyone of where the nest is, the species, when it was found and at what stage the nest is at (nest only, nest with eggs, chicks, not active). Each recorder will then follow 'their' nests and submit them to the BTO (usually via the ringing group) at the end of the season/nest completion.



Last years nest locations on a shared Google map

Across the country there are some species that have been nesting for some time already including Grey Heron, Raven, Dipper, Stock Dove, Cormorant and Crossbill. The BTO NRS Forum has come alive with reports of nests, includes a Peregrine laying in Woking, Surrey (webcam link), a Woodpigeon squab about two weeks old in North Cornwall and Moorhen, Mistle Thrush and Ring-necked Parakeet with eggs in London. Dippers have full clutches in the Scottish Borders and some chicks have already been ringed in Wales. A Stock Dove in North Norfolk must have fledged by now as well.


 

Blackbird nest - photo by Lee Barber

Nest recording is vital to our understanding of productivity and every nest counts! It is amazing how much difference one nest record can make. By looking at the NRS submission totals, you can see what nests have been recorded previously (2016 records are still being analysed). In 2015, just 24 Goldcrest, 15 Snipe and nine Grasshopper Warbler were recorded in the whole country. Take that down to the county level and you could make a big difference to the totals, especially if you focus on one particular species. Open nesting birds are particularly under recorded because they are generally harder to find, but with a little practice and patience it can be done. Click here to find out how to take part and develop your nesting skills.

What a whopper!

A Blackbird weighing 125g is not particularly unusual... in winter. Catching three females at this weight in the second week in April is unusual.

My husband Jeff and I have been studying the Blackbirds in our Thetford garden since we moved here in 1996. Our local breeders are joined by their continental cousins in mid-November each year and they co-exist.  In the mid-winter, particularly when there is snow, their weights peak as they put on fat to survive the cold. In January of this year we caught 52 Blackbirds, seven were over 125g
in weight, indeed one weighed a massive 150g. As Spring approaches, so weights drop.  For the local breeders weights continue to fall – typically a breeding Blackbird will be under 100g with some getting below 90g. For the Continental birds it is a different story – having dropped to close to 100g they will start to increase again, this time putting on fat to fuel their migration. We have had two Norwegian ringed birds in our garden giving a good indication of where many of these birds are off to. Typically we think birds depart our garden at weights of 110g to 120g.

Male Blackbird - Allison Kew

Like most people we look forward to the Spring.  For us one of the features of Spring is the departure of the Continental Blackbirds, allowing us to focus on colour-ringing and re-sighting our breeding birds for our RAS project. We know when the Continentals have gone as the Blackbirds behave differently and we stop catching heavy birds. The date varies from year to year but is normally in the last two weeks in March.

Female Blackbird - Allison Kew

This year we’re still waiting – departure for many of our Blackbirds is at least a couple of weeks later than ever before, the strong, cold, easterly winds not providing good migration conditions.  Over the weekend of 6 and 7 April we had more birds over 117g than in all of the other Aprils combined and one was still here on the 13 April.  Indeed we’ve never had females at 125g in April before – this year there have been three.  All signs of delayed migration. We’re expecting that, with the more favourable weather conditions, all the Continentals will have gone by the coming weekend.

Meanwhile, our local breeders are also slow to get going - by now we’d expect most females to be feeding young and have some doing that, but nowhere near as many as normal.
Just goes to show how useful it is to collect measurements of birds. Without recording wing-length and weight we’d not understand what the Blackbirds were up to as migrants and residents can’t be distinguished by eye. 

Thanks particularly to Jo Lashwood who has done a lot of the recent hard work on this project and actually caught the 150g Blackbird.

Allison Kew
CES & RAS Organiser

Orkney Greylags in Norfolk

We have just got details through of some very bizarre movements of Orkney-bred Greylag Geese, which have now found Norfolk to their liking (but who wouldn't?!).

Both DIS and DIU were ringed (and given their orange neck collars) as goslings on 13 July 2008 on Birsay, Orkney. Both were then seen together in Suffolk (Lound Waterworks) on 21-23 December 2008 before moving to Norfolk (Strumpshaw Fen and Buckenham Marshes) on 24 December. They stayed right through to the end of January before being seen back, still together, on Orkney on 6 April 2009. This winter they are now both back at Buckenham, but this time joined by HAJ and HAK, ringed as goslings on Birsay on 9 July 2009! Quite a pattern developing!


These movements seem quite exceptional, but then the Orkney Greylag project only started in summer 2008, so maybe this isn't so new... The project now has funding for another four years so it'll be fascinating to see if more Orkney birds make it to our part of the world.

Interestingly, a lot of the Icelandic-ringed birds now spend their winters in Orkney instead of heading further south to places like Aberdeenshire, Tayside and even Highland. So what are these birds doing??? So all we need are more sightings of neck-collared birds, so keep your eyes out over the winter! Any records can be submitted via www.ring.ac

Interestingly Norfolk has also hosted Greylags from other strange places, with a Spanish-ringed bird (of the Scandinavian population) spending some time in the county (June-August 2004 and February 2005) and also recoveries from as far afield Poland and Germany!

Thanks to Alan Leitch for the info on these birds Alan and Andrew Easton for the photos of the birds in Orkney and Norfolk.

Blue Tits on the move???...

We rarely hear of long-distance movements of Blue Tits, so it was quite exciting to hear last week of a Belgian-ringed bird in Norfolk. This was recaught by David Fuller at his site near Garboldisham. You'd imagine this would be juvenile dispersal, but we found out today that BLB-10945741 was ringed at Essen, northern Belgium, on 10 October 2008, almost a year previously!


View Blue Tits in a larger map

The map above shows all foreign movements of Blue Tits, with blue pins marking BTO-ringed birds found abroad and green pins marking foreign-ringed birds found here (the red pins show the movement of David's bird). It is interesting that of the 10 movements of BTO- ringed birds, seven were ringed in Kent and no less than four were ringed at Dungeness Bird Observatory! There have only been four foreign-ringed birds found here (all recaught), and one of these turned up at Dungeness as well!

So the Blue Tits in your garden might not be as uninteresting and resident as you might think.....