This is another one I've shamelessly posted myself after a recent short email exchange based on this: iberianature entry here
http://www.iberianature.com/#peregrines_BarcelonaDuring the hacking work in 1999 in the Church of Santa Maria del Pi, a pair of kestrels (Falco tinnunculus) nesting in the bell tower brought food both to their chicks and the peregrine chicks inside the nest box. They almost always brought swifts (Apus apus) and house sparrows (Passer domesticus ). When the young peregrines left the nest box, they lived together with the young kestrels and could often be seen perched together. This phenomenon is somewhat surprising if we consider that both kestrels and peregrines are highly territorial species which zealously and aggressively protect their offspring. Moreover, peregrines will occasionally capture and eat kestrels.
....it doesn't quite make it clear if the Kestrels were officially parenting the perries or just feeding them because they were there.
I have heard of perries being deliberately put into kestrel nests as a means of seeding an area. It must be bloody hard work for the kestrels once their charges get big! And some danger that the young might eat their foster parents.
I spose what cuckoos do shouldn't make any of this too surprising.Answer
Right, you were right to query this. It's not at all clear
As a result they are going to write up and publish a proper report on this incident - which I think is one the most interesting parts of their web.
Very briefly - a more detailed desciption to come when they get round to it -
Eduard (the Catalan in charge of the programme) looked for suitable sites in the year in question. He didn't realise this one he had chosen had kestrels nesting "next door". When their own chicks had fledged - which was early, before the peregrines- The adult kestrels heard the peregrines and started to feed them - but they couldn't see them as they were in a box. They dropped headless swifts and sparrows through the letterbox as it were. They also continued to feed their young, now-flying birds. When the peregrines emerged both species seem to have got on fine, and were frequently seen perching together.
The next year they repeated the hacking in the same site, but on this occasion the kestrels hatched and fledged later than the peregrines, and the adult kestrels did not feed the young peregrines.
> More soon
Nick
