24 Nov 2014

Talking tertials

Saturday saw a 3.15 wake-up call as I was going across to Bangor to join the rest of the SCAN ringing team attempting to canon net Redshank & we had to meet up at 05.45 to set the nets in the dark! With high tide around 10.30 we didn't have the luxury of setting up in daylight!

We had the nets set pretty quickly and the majority of the team settled down in the hide for a long vigil as dawn broke and the tide rose. Once again luck was on our side and we made a good catch comprising 126 Redshank, 8 Dunlin & a single Curlew.

It was a good opportunity to look at ageing the Redshank something generally done by the state of the tertials. Juveniles (age code 3 born this year) generally have very worn tertials with the weaker white 'teeth' worn away so the edge resembles a bread knife blade -see below.

Very occasionally these can be so badly worn that very little white is visible at all. This can cause confusion making the bird look similar to an adult although other plumage / bare part characteristics can be used to determining the correct age. Juvenile Redshanks generally have paler legs than adults and are a yellowish orange.

Adult tertials shown on the bird below:

There is a racial separation based on size between populations of Redshank with birds from further north (Iceland & Scandinavia) being bigger than our British birds so measurements were taken to help determine the origins of these birds wintering in N Wales.

A number of juveniles were quite 'runty' and we caught one unfortunate bird that had a severe case of rickets - see below. A couple were very undersized and underweight and if we have a cold winter they'll be unlikely to survive.

A great session and we were finished and packed up by 12.00 - enough time for me to catch up on some sleep in the conservatory!

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