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.

Kingfisher catastrophe

Farewell

Well I’m feeling pretty gutted right now. The nest site I’ve been monitoring and photographing under license for the last 3 months has been abandoned. For the last 3 weeks I’ve noticed that I was only seeing the male coming in to the burrow with food. No sign of the female. Also, the male was only bringing in fish (although they were pretty large fish) about every 45 minutes, which on reflection I don’t think would be enough to keep a brood of chicks going.

The first nest burrow at this site was actually dug out from above, I’m assuming by the mink that I’ve seen regularly along the bank while watching the nest site from my hide.

I was really hoping that the second attempt would be successful as another nest site a mile down river had also been dug out from above in exactly the same way.

The second burrow was much deeper and there is no sign of any disturbance, so I’m pretty sure that it’s the loss of the female that’s stuffed things up.

The male seemed to stop feeding about a week ago and on my last couple of visits I’ve only seen the male flying through the territory. He’s no longer perching outside the nest burrow, which I expect contains the corpses of the chicks.

I’ve no way of knowing what happened to the female, but the extent to which Mink are endemic on this stretch of the Trent in Staffordshire is a real worry in relation to the Kingfishers. I’m convinced that the 2 nest sites were dug out by Mink as they were both only about 12 inches or so deep and the holes were dug straight down to nests containing chicks, as evidenced by the fish scale debris left in the exposed nest chambers. The 2 nests were also destroyed within a few days of each other in late April.

The fact that Swans nesting a hundred yards upstream only have one Signet left is also perhaps indicative of an environment suffering from an invasive predator.

Ironically, this is probably the ongoing fall out from when thousands of Mink were released in North Staffordshire in 1998 by animal rights campaigners.

Here are images of the 2 nest burrows after they were dug out. the close up shows the interior with the remainder of fish scales in the nest chamber. Both of these burrows were dug straight down into, so presumably whatever did this (I’mĀ assumingĀ Mink, was able to hear the chicks).