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Sunday 23 August 2020

Blackcap City

We postponed yesterday's session at Belvide for what turned out to be  not such a bad day after all. So it was a bit of a concern if we had made the right decision. As things turned out we had a really good morning with 131 new birds ringed of which 63 were Blackcaps--entirely consistent with their increasing migration at this time of year. We hope there will be plenty more over the coming weeks.

Star bird of the session was our second Grasshopper Warbler of the season. We get fewer than one per year so two in a couple of weeks is special. This bird was a classic juvenile, fledged this year with pristine feathers and no fading of colours:-

Compare this with the adult bird for a few days ago and you can see the difference in the colour and wear on the plumage
At this time of year young Hirundines ( Swallows and Martins) often gather over the res on cool mornings. This was the first such morning and a few gathered and we were lucky to catch 5 Sand Martins and one House Martin. The appearance of their plumage makes them very easy to age:-
You can see the wing and head feathers have buffish white outer edges ( as have most of the back feathers)--which makes this a juvenile--adults are plain brown.
House Martins are just as easy to age:-
The thre feathers in front of the thumb are called 'tertials' and are where the wing meets the body. In juvenile House Martins these feathers have white tips as can clearly be seen, The rest of the wing is dull brown also-unlike the glossy blue in adults.


 

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