Update from the Pensthorpe kestrel and sparrowhawk nests
At the end of Springwatch we promised we'd keep following our kestrel and sparrowhawk families and update you on their progress. The good news from the kestrel nest is that dad has continued to be an excellent provider. All the chicks now look very ready to fledge. Not so good news from the sparrowhawk nest though...
Our plucky Pensthorpe kestrels
At the end of Springwatch 2010 our Pensthorpe kestrel family had us all worried after the sad news that the mother kestrel had been killed by a lorry. But since this tragic affair the kestrel family have gone from strength to strength.
The kestrels from earlier days
Not only did the kestrel chicks start to take more of an active role in feeding themselves by picking at the food in their nest box, but their father had been doing a sterling job of providing for them on his own.
Kestrel males have to be good hunters as they provide all the food for the female and the chicks during the brooding period. Female parents usually only hunt as the brood get bigger and will usually hunt in areas nearby. It looks like our male is doing his job well but good weather will definitely have helped... males would sometimes take food to cache for the female to pick up and then break up for the chicks.
So it's all positivity and progress with our kestrel family as the good weather holds out and the nestlings are all looking healthy . We expect that they'll be fledging in the next few days and one chick in particular has been doing a lot of stretching and preening to the point of seemingly annoying its siblings.
The mystery of the Pensthorpe sparrowhawk nest
Expert Dave Culley reports that it's been a bad year for sparrowhawks up and down the country. One reason could be that the harsh winter meant that females weren't able to put on enough weight to properly brood the eggs and chicks.
Sadly it looks like our sparrowhawk family have contributed to these statistics...
When the series finished all five chicks were doing well and the one unhatched egg was still there. The male was also making appearances and bringing food to the nest.
But when Jo, one of our minicams team, went back to Pensthorpe last weekend to investigate more, things had changed. On the first day he saw only one chick. There was no evidence of any of the other chicks or the egg. Jo saw Mum and also saw the chick poo, both of which suggested the chick was being fed.
On Sunday when Jo returned at 12.30pm after filming the kestrels, the nest was completely empty and there was no sign of the female.
Ed, the warden at Pensthorpe, said he saw a sparrowhawk flying towards the woods where the nest was on Sunday morning. It was carrying food, so possibly it was our female. So does this mean the chick was still alive before Jo visited? Possibly, but we can't be sure.
So what happened?
The short answer is that we just don't know. But our experts have put forward some theories. Dave Culley's best guess is that magpies and jays are the culprits. They go to nests in gangs of three to four. Working as a team, they have two methods of attack: kill all the chicks in one go and take a few away at a time, or kill a couple and take them away and then come back and do the same until they're all gone. Dave has seen 7-12 day-old chicks taken like this.
Mike Powles, Pensthorpe's wildlife expert, thought it could be a number of reasons but believed that tawny owl predation was most likely in this instance. For Chris Packham, the likely culprit was another raptor. Both buzzards and goshawks are know to take pre-fledglings from nests, he said.
A sad end for our sparrowhawks but unfortunately when you are telling real stories in real time a happy ending can never be guaranteed.
Jo took some footage of both the nests, which we'll post here just as soon as we can.