Almost there...

Post date: Aug 17, 2016 6:34:38 PM

It has been quite a while since I updated this blog, but I haven't been idle! Since my last post, I carried out three sessions at the Constant-effort site, the last one today; as well as a short session at another site, with some visitors from Portugal. However, results have been, as always, immediately posted here, where all the details of captures and recaptures as well as the annual totals of adults and juveniles can be seen.

With my visitors, I caught few but interesting birds, including a Marsh Warbler, a Whinchat, a Lesser Whitethroat and a Redstart!

Detail of the wing of a young male Whinchat (Saxicola rubetra)

Young female Redstart (P. phoenicurus)

The three CES sessions produced a decent number of birds (52, 48 and 40, 9-10 species in each), but somewhat lower than expected for the time of the year. Although the weather has been less than ideal, with quite a lot of wind and rain, this does not seem to be the cause, as today's session was undertaken in pretty much perfect conditions and the numbers were even lower. It does seem that there are fewer birds this year, even though some species increased (e.g. Reed Buntings; see Results).

Reed and Sedge Warblers have dominated, as well as Chiffchaffs (though the latter declined today with only 5 caught). Juvenile Marsh Warblers turned up at the beginning of August, but seem fewer than in previous years. Today, I finally caught two Wrens (as has been typical, juveniles seem to disperse to the reeds later in the season), thus adding a new species to the CES 2016. Otherwise, there were also Willow Warblers, Robins, a Redstart, plenty of juvenile Dunnocks, a few Blackcaps, Garden Warblers and Reed Buntings, as well as Blue and Great Tits.

Juvenile Marsh warbler (Acrocephalus palustris), showing the typical rather shorter, thicker bill and gentler expression than the Reed Warbler (A. scirpaceus), as well as the long primary projection and wing formula

The biggest frustration has been the absence of captures of Bearded Tits, which have been calling frequently near the CES during the past three weeks, and even passed a couple of meters from the nets, but none was caught so far.

Migration is definitely underway. Adult Reed and Sedge Warblers had fat scores up to 6 (out of 8) at the beginning of August. Also, the number of adults (which migrate first) also seem to have declined, as today there was only one adult Reed Warbler (out of 11), and all 10 Sedge Warblers were young. However, there are some late breeders as well, as proved by a juvenile Reed Warbler caught today with very short and growing remiges (I estimate that it fledged in the last two days). Curiously, I also found a juvenile Song Trush on the forest ground that must have just jumped from the nest and it could not fly yet. It was caught by hand, ringed and put at the same site, so it could be fed by the adults.

Despite many birds are already migrating, some also just left the nest as the Reed Warbler (A. scirpaceus; above) and the Song Thrush (Turdus philomelus; below) caught on 17 August!

One more session will be performed before the end of August to complete the constant-effort method for this year, and more ringing will follow to get migrants and sample residents for the malaria study. It seems this year I will not be ringing migrants in Portugal, particularly the Aquatic Warblers, which have already arrived there, as I will be involved in a new project on House Sparrows. So expect more news soon!

JMN