By Liz Corry
The most significant event for Jersey’s free-living chough population this month has been the disappearance of Blue, the breeding female, who has not been seen since the end of the day on Sunday 31st January.
The only potential clue to her disappearance was on 2nd February when the group were observed actively following a peregrine back from Sorel Point to the grazed headland. When the group returned to the aviary for supplemental feed we placed the food dishes behind the aviary on the grazed land. This way the birds settle on the ground (providing there are no mountain bikers or walkers around) and we can get a clear close-up view of how everyone is.
As Green, partner to Blue, came into land it was clear he had a problem with his ‘landing gear’, his right leg was dangling out to the side. When he settled on the ground it was clear to see he was hobbling and reluctant to put any weight on the leg. He was feeding fine and did not seem too perturbed by it.
Green has gone through quite a few ordeals in his time living at Sorel including locking talons with a peregrine on his first ever flight away from the aviary in 2013. We monitored him closely for the next 24 hours, but he, the trooper that he is, recovered quickly and was using the leg again the next morning. Could Blue have fallen prey to a peregrine?
The weather had not been too kind, but not so severe that Blue or the rest of the group were in any danger. She was present at all the feeds before her disappearance and roosting in the relative safety of the aviary.
Whatever the reason, the fact is she has left the group, and life goes on for the rest. None more so than for Green who within the space of a week had re-paired. Black, a single female, wasted no time in making her presence known. Our first true confirmation of the pairing was on the 8th when he was observed passing food to her. This is a bonding exercise which proves to the female that he can provide for her if she decides to incubate eggs. Over the course of the month their bond has strengthened.
Whilst it is disheartening to lose a proven breeding female, the fact that Green has re-paired is encouraging. It is also good news for Black as she tried to nest last year and failed in finding a reliable male.
It all means that we head into the new breeding season with three strong pairings all with experience of nest-building at the very least.
Another interesting change which occurred when Blue left the group was with roost site preferences. Checks in the first half of the month showed that two choughs had decided to re-join Mauve and White in roosting at the quarry. Since last October Green, Black, Blue, Red and Dingle had roosted at the aviary with the juveniles instead of the quarry. Now it looks like Green and Black are once again roosting in the quarry. Could this be an indicator as to where they will nest this year?
There was a slight chance that Red and Dingle were the two not roosting at the aviary.
Our confirmation, however, that it was not them came on the evening of 6th February. The weather had been clear and calm so the choughs were active right up until the sunset at 17:30. The three pairs were missing from the group.
At 17:38 with light almost gone, two choughs shot back from the direction of the motocross track and went straight into the external roost box. It was Red and Dingle.
As the winter weather eases off and day length increases we have seen a change in the choughs’ behaviour.
The group are spending a bit more time away from the grazed land and moving round to Sorel Point and the motocross area. As far as we know they have not been over to Crabbé at all this month and only occasionally venture over to Devil’s Hole.
We are very grateful to a private donor and neighbour of the choughs who generously gave a donation to help contribute to the cost of repairing the aviary roof. Durrell’s Maintenance Department will hopefully start work in March. I’m sure the choughs will be very thankful, even if it means they have to find an alternative watering hole.