Very difficult one ! It's in any case a Tyrant flycatcher and I'm quite sure one that belongs to the genus Pitangus, in English Kiskadee. There are several species and their main difference is size so I realy can't say which species is on the picture.
In the late 1980-ties I succesfully bred the Greater Kiskadee at Walsrode.
It was not a big bird. I've seen several times before Great Kiskadee (Pitangus sulphuratus), including in Rotterdam, Vogelpark Avifauna, Plzen. I think that is probably the Lesser Kiskadee (Philohydor lictor). This species has been seen before in 2010 at the Zoo Duisburg. Still, thank you for the interesting information.
this is a great kiskadee, Pitangus sulphuratus. It is currently (at least last week) free in the rainforest hall and its distintive call can be heard occasionally, too. No sign for it or any other tyrant flycatcher for that matter, but the signs in this hall seemed way off anyway (much more than on my earlier visits) -- several species listed that I believe haven't been there for quite some time, while I did see others that lacked signs.
