Post date: May 26, 2014 6:13:21 PM
The third constant effort session took place this morning at Krankesjön. It was a mild sunny day, with temperatures going from 9°C at 4:45, when I opened the nets, to 23°C (although it felt warmer!) when the nets were closed at 10:45. The number of birds was pretty similar to the last session, but the composition was quite different: instead of Sedge Warblers (Acrocephalus schoenobaenus), which were singing but did not get trapped, I captured quite a few Reed Warblers and a pair of Marsh Warblers (A. palustris; the first, and second of the year). These two species breed side by side at this site, which provides a great opportunity to learn about them, especially for someone like me, who has rather limited experience with eastern birds.
There was also a Whitethroat (Sylvia communis), the first for the CES and, surprisingly, no Willow Warblers (Phylloscopus trochilus). It is possible that some of these Acrocephalus arrived recently, occupying territories near the trapping site, but the variability so far between sessions is interesting. The diversity is high (a lot of species given the number of birds), and species change quite a lot between sessions probably because I am using few nets (just four, 54 m), which cannot sample the local diversity adequately in a single session. Anyway, there will be 12 sessions as demanded by the CES method, and the low number of nets is necessary because there will be a time when the number of birds caught will be quite high!
The first juvenile of the season was also caught: a recently-fledged Blackbird (Turdus merula) with the remiges still growing. Soon there will be a lot of them of many species!
The site is still quite difficult to access and, again, managed to get quite muddy and wet (which actually felt good with the warm weather!). Addressing this is a first priority at the moment, especially if other people start attending the sessions, which demand that the nets are visited 13 times (setting up plus half-an-hour net rounds)!
The few birds caught still allow me to have some time to detect and photograph dragonflies and other creatures. There are loads of them now, but for that you'll have to check my Flickr site, as this post is already getting too long!
Cheers
Júlio