If you go down to the woods today you could be in for a big surprise! (photos)

A walk through the woods at this time of year can produce many summer visitors singing looking for a mate. But what is that unfamilar sound that you just can't place "jep jep jep jep weep weep de de de de"? You get a view of the bird and some features are somewhat intermediate between Chiffchaff and Willow Warbler. Well you could just be looking at Irelands first Iberian Chiffchaff.
There are pitfalls with mixed singers and hybrids but if the bird sounds like this then its a very good starting point : http://www.youtube.com/watch?v=5fSypNWENjY

Daniel Lopez Velasco

Check the primary projection on this bird. It is longer than on Common Chiffchaff and closer to what would be expected on Willow Warbler. Rump, upper tail coverts and upperparts olive with green hues.

Daniel Lopez Velasco

Iberian Chiffchaff has a more open faced expression than Common Chiffchaff. This is caused by a combination of weakly marked cheeks and eye stripe and an indistinct lower eye ring (White in Common Chiffchaff).

Daniel Lopez Velasco

There have been at least five in the UK this spring with two new arrivals in the last couple of days (including the first for Wales). While it seems an unlikely vagrant to Northern Ireland a couple of years ago a bird was heard singing briefly but disappeared and was never positively identified. So keep your ears open when you go down to the woods!

(special thanks to Daniel Lopez Velasco)