Friday 18 August 2023

Mist netting 15/8/2023

After a spot of cow herding, 8 nets were set around the Colyford Common end of the reserve. It was the best turn out for some time, with 8 ringers attending. The first couple of rounds we had more ringers than birds, and it looked like there would be a lot of thumb-twiddling during the morning. However, at around 9:30 it livened up and we had an excellent session, catching 74 birds of 18 species.

Whilst birding, Willow Warblers &  Chiffchafs can be quite difficult to tell apart unless they're singing. However, a pair of young birds caught together show how different they can be.

Chiffchaff in complete juvenile plumage on the left. Young Willow Warbler on the right.


In the hand, a close look at the wing can differentiate between the species, even in birds that have the same general appearance. A Chiffchaff will have the outer 6 primary flight feathers emarginated, but a Willow Warbler will only be emarginated to the 5th feather. 

The wing of a Willow Warbler as only the outer 5 feathers emarginated
(feathers 1 & 2 partly obscured in this photo)

We caught 15 Blackcaps, all of which were this year's youngsters, although they had been hatched at various times & were in different stages of their post-juvenile moult; some were still in complete juvenile plumage, some were part way through their moult, and one had finished. 

Blackcap undergoing post-juvenile moult, still with juvenile head feathers.

Blackcap wing showing greater coverts in various stages of growth, this bird having lost the greater coverts grown in the nest. 

16 of the 17 Goldfinches caught were juveniles which hadn't yet completed their post-juvenile moult to acquire their red faces.

Juvenile Goldfinch

The star of the show though was the Marsh Tit, a first for the site!

Marsh Tit

Part of the Team!


Rung

Re-trapped (original ringing date)

Blackbird

2

1 (22/5/23)

Blackcap

15


Blue Tit

1

1 (13/7/23)

Chiffchaff

2


Dunnock

1

2 (12/6/23 & 2/11/21)

Goldfinch

17


Great Tit

1


Greenfinch

9


House Sparrow

6


Linnet

1


Marsh Tit

1


Reed Warbler

1


Robin

6


Song Thrush

1


Stonechat

1


Swallow 

1


Willow Warbler

2


Wren

1

1 (22/5/23)


69

5