OK, finally some more on my latest visit to the stream (24 April).
The weather was a bit grey, but OK for observing fish. Off and on there were a few drops of rain. The water level in the stream was maybe 25 cm higher than I remember from before, but the temperature was similar. Overall the vegetation has grown more dense, especially the aquarium plants now cover at least 70% of the stream bottom. Even though it's a jogging/dogwalking/horseriding area there were few people around, probably because of the weather. The most surprising finding was a little bittern, a very rare bird which I had never seen before in real life. I suspect that this bird was on migration and it does not usually live around this small stream.
Green frogs were off and on calling along the stream. I caught 3, which were all lake frogs (Pelophylax ridibundus). In the stream, I found both eggs and 3 cm long tadpoles of this species. Maybe I should note that identification of European green frogs is not easy: in central Europe there are 2 species and a bunch of hybrid forms (called "green frog" or "edible frog" - Pelophylax kl. esculentus - ) that can look similar to the parental species. With adult frogs in hands I am fairly confident about identification, and in this case the calls confirmed which species is present along the stream - it is entirely possible that some hybrids are also present, but I did not see/hear any of these.
Last edited by illustrator
on Wed May 13, 2009 4:49 am, edited 2 times in total.