It has been an excellent spring for Greenish Warblers in Germany with several breeding records and stragglers far away from the more regular sites. Late August is the best time in autumn for this species on Helgoland, as you can see in the histogram below. Shown are all records on Helgoland (n = 99) from 1840-2009, taken from the book “Die Vogelwelt der Insel Helgoland”, published in 2011 (see http://www.oag-helgoland.de/pub/Avifauna_en.html)
So I was not very surprised when a few days ago I heard a Greenish Warbler calling just in front of my window. It was constantly calling very loud, but I was phoning with my chief, so I could not concentrate too much on the bird. When the phone call was finished, it stopped calling and I saw it flying over the roof, never to be seen or heard that day again. Next day it was again calling at the same site, but I could not find the day. Finally, on 24.8. I heard the bird again (once it was even singing) and saw it for a few seconds. The fresh plumage indicated a first-year.
Also on 24.8., I was mist-netting on another part of the island, but catching was rather slow, so I went around with my bins and saw another Greenish Warbler. It was an obvious first-year bird with a strong contrast between a greyish green back and bright greenish primary edges. Another birder took some pictures, then I had to check the mistnets again.
Picture taken by Jan-Peter Daniels
When I went back to the site 2 hours later, I played the Greenish Warbler call and immediately a bird popped up. I thought the bird is back, however, this bird had a different upperpart colouration and therefore was a 3rd bird, also a first-year. It showed well for a few minutes and I was able to take some pictures:
So 3 first-year birds on a single day – this has never been experienced so far on Helgoland on autumn migration (although several times in spring). Is there an influx going on?