Nest predation

nest-predation2

While everything has been going well with the Dutch kingfishers, on the Trent things have taken a disastrous turn. My local birds appeared to have been running about 2 weeks behind the dutch birds and I was expecting to see fish being taken into the nest this weekend. On arrival this morning at the nest site I sensed something was wrong, both birds were outside the nest flying upstream and downstream and perching below the nest borrow entrance. The female wouldn’t enter the burrow, and while the male entered, he came out immediately.

My usual viewpoint is on the opposite bank from the nest, so I had to drive and walk across a field to access the nest bank. As soon as I arrived I could see that the nest had been dug out from above, there were egg fragments on the ground, and a hole going straight down to the nest chamber, which was about 10 inches below the surface.

nest-predation1This has happened before at this site, in 2011 the same thing happened, so I had placed a metal grid above the nest chamber for each of the last two years. The metal grid I’d placed above the nest this year looks like it was just a bit too far back, and the unknown predator had dug down at the side of it. I’d assumed the nest would be about 3ft from the bank face, but unfortunately it was only about 18 inches deep, so it remained exposed, despite my efforts to protect it.

I had thought that it was the noise of chicks in the nest that might bring about this type of raid, however, this nest obviously still contained eggs, so I’m assuming that the predator was using scent. It’s probably fair to assume that the regurgitated pellets that the kingfishers use to line the floor of the nest chamber must have a fairly pungent scent.

The only positive I can take from this is that both adult birds appeared to be fine. If they dig a new burrow I will use a larger grid to try and ensure that the burrow is protected. It does concern me though, that if this has happened twice in three years at this location, how often is this happening at un-monitored kingfisher nests along the river.

Posted in Kingfisher Diary and tagged , , , , , , , .

One Comment

  1. Terrible news – as you say – I wonder how much of this goes on at other sites! I wonder what might be the culprit – mink?

    Cheers,
    Rob

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