Sunday, 9 September 2018

Marsworth - 2nd September 2018 - Pied Fly Surprise

Nets: 240'
Tapes: Blackcap, Chiffchaff, Willow Warbler, Tree Pipit
Ringers: LL, MCC, PN


New
Retraps
Total
Dunnock
1

1
Chiffchaff
4
1
5
Willow Warbler
4

4
Reed Warbler
1

1
Blackcap
44
6
50
Blue Tit
2

2
Lesser Whitethroat
1

1
Pied Flycatcher
1

1
Wren
1

1
Robin
1
2
3
Goldcrest

1
1
Lotti

2
2
Bullfinch
1

1

61
12
73

Mike and I went to Marsworth with new (soon to be) trainee on their first taster session. It was the first day of being able to use tapes after finishing the CES ringing on Friday and we only put up four nets. It is clear that Blackcaps have had a good breeding season and the tape lures work...Luckily, our new member proved very capable and got stuck-in scribing - not usually a job for a beginner!!
A bird in net 4 caught my eye, brown with a white wing-bar, chaffinch? No! Pied Flycatcher, excellent!! A first for Marsworth. We aged it as a juvenile from the way the white on the tertials forms a step at the shaft. Svensson says the juvenile greater coverts should have large white tips often forming wedges or steps. Our bird had some inner GC's which matched the description although the outer ones were more buffy.  Svensson also says that it is possible to determine the sex of a few first year males from the black 1st - 3rd tail feathers and jet-black longest upper tail coverts and we felt ours were sufficiently black to sex it as a male.
Pied Flycatcher
Black upper tail coverts


White goes up the shaft on the tertials and inner GC

Lesser Whitethroat
We finished with 50 Blackcaps and it was notable that they were all juveniles and fairly low weights and only a small percentage were carrying any fat. We only caught one Reed Warbler which was strange but possibly due to much of the reed having collapsed in the heavy rain a couple of weeks ago. Three of the Chiffchaff were quite young and only just starting post-juvenile moult. We also caught a Lesser Whitethroat which appeared to have changed one outer tail feather, showing a nice contrast between the juvenile and adult type feathers.
Lesser Whitethroat

















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