26 Jan 2015

A calidrid swarm

The weekend started well with a walk round Stanney Woods Friday afternoon. The first time I'd been able to get out locally for ages. I'd hoped the recent cold weather might have resulted in a Woodcock movement as we'll often find them deep in the woods as they move ahead of the frozen ground. They're very elusive and way off the normal tracks. Sure enough I flushed two under the same holly bush deep in the wood where the ground is boggy and there's plenty of cover.

Saturday saw a planned SCAN canon netting attempt for the elusive Dunlin. Catches have been poor over the last couple of years. Not because Dunlin are scarce but because every time we do a recce and set the nets where they are expected to roost they decide to move elsewhere. Its been very frustrating.

The alarm was set for 06.00 to ensure I could get a good breakfast before meeting the rest of the team at the designated time of 08.15

This time the best laid plans of the ringing team finally hit pay dirt! Over 770 Dunlin and a smattering of Redshank were caught in one net. After extracting the birds and putting them in nice warm dark holding cages we took the opportunity to grab a sandwich and a drink before splitting the team into 3 - 2 processing teams. Each  aged each bird and measured wing length, total bill / head length and bill to feather length (this helps assign to race) and weight whilst the ringing team concentrated on putting the rings on the birds.  Among the birds were a number of retraps to provide useful data on site fidelity and survival rates. Although of no real scientific interest we caught 4 controls - 2 wearing Swedish ringing scheme rings and 2 with German.

Rachel checking the ring number before ageing and measuring wing.

Dunlin can be aged in winter by the retained juvenile wing coverts which have a creamy brown edge  - the bird below is a juvenile bird (2nd calendar year).
 Whilst this one with white fringing to the coverts is an adult so is in at least its 3rd Calendar year.

We also caught a couple of old retraps that hadn't been seen since the ringing date. One had been ringed in Bangor harbour in 2001. Its incredible to think how far this bird has flown in its lifetime.

The 'other' processing team relaxing after finishing processing nearly 800 birds.

What surprised me was how warm the little birds were. A proper little hand warmer. The legs and feet were noticeably cold though - like all wading birds Dunlin have the ability to restrict the blood supply to their feet to conserve energy in cold weather. Unfortunately ringers don't have that ability and there were a few people with cold feet due to leaking waders.

A great day and a well organised team! I got home starving hungry, filthy dirty and in desperate need of some sleep. Luckily Sunday gave me a bit of a lie in as  I couldn't make the Sunday ringing session due to a commitment to undertake the WeBs count on Hilbre over the high tide.

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