Yellow Wags, Farlington Marshes - September 2014

August and September are the best months for catching Yellow Wagtails in Hampshire. Unfortunately we didn't manage to do any sessions in August, but we have managed two sessions so far in September. At Farlington Marshes the Yellow Wags spend most of the day in the fields with cattle, but at dusk they come into roost in the reed bed. We did our first session last week and another last night, and have amassed a total of 57 new birds so far.

Yellow Wagtail - Farlington Marshes

In theory Yellow Wagtails are pretty straight forward to age; adults undergo a complete post breeding moult and juveniles only a partial post juvenile moult. Adults therefore will have fresh plumage with the medium and greater coverts and tertials tipped a yellowish-green or buffish colour. Juveniles however have slightly worn medium and greater coverts and tertials, with white fringing.

Juvenile Yellow Wagtail - Note the white fringing to the greater coverts and occasional whiter fringed medium covert

Juvenile Yellow Wagtail - All of the greater coverts in this bird are juvenile, the medium coverts are post juvenile

Juvenile Yellow Wagtail - Note the white fringed juvenile medium coverts, which stand out from the buff fringed post juvenile ones. The greater coverts are all post juvenile

Adult Yellow Wagtail - Note the yellowish-green fringed medium and greater coverts and uniform generally warmer plumage

Adult Yellow Wagtail - Note the uniform yellowish-green fringing on all of the wing feathers.

Whilst waiting for the wagtails to come to roost other species of note that we recorded included three Whinchats, one Stonechat, a Green Sandpiper, 50+ Greenshank, Little Egret and at least 100 Black-tailed Godwits.