Natural Selection

Continuing the catch-up of things I’ve been up to lately I was asked by Kane Brides to check Blackpool Zoo for the national Naturalised Barnacle Goose survey. Visitors to the zoo would be forgiven for thinking these birds are part of the collection, but they aren’t and leave to roost at Marton Mere or Staining Nook each evening. So like the flock at Knowsley Safari Park they came under the auspices of the national count.

The helpful staff at Visitor Services provided me with a research tabard. This felt a little grandiose for a count of feral geese. I imagine it’s the only time I will wander round a zoo doing anything that vaguely resembles ‘research’.

A flock of vocal geese didn’t take much tracking down. One of the Visitor Services staff had said numbers were burgeoning, whereas the flock seemed depleted when I saw it at Staining Nook a few weeks back. So I was interested to see how many birds were present. There had been 27 at the Nook, and the highest of three counts in the zoo as birds left and returned was 28.

I also checked for other wild waterbirds in the parts of the zoo with some water. There were 16 Mallard across three enclosures, and nine Moorhen over five sites even including the elephant enclosure. A heron fed in the flamingo and pelican lake shallows, and a Greylag Goose was on there.

Pair of Mallard in the moat around the gorilla island

It was interesting to see how even though the Barnacles were as approachable as you might expect, and generally loafing about, territorial skirmished broke out even though they weren’t being fed. The start and end of one turf war follow below.

One of the interesting things about this flock to me is their flexible behaviour. In the zoo grounds they obviously feel safe from threat and can be readily approached. When they move to their roost site in the evening they are not particularly approachable, presumably because of the risk of predator attack.

Feral Barnacle Geese are doing well nationally at a time when truly wild birds are at a low ebb, not least as a result of avian influenza. Wild and feral birds sometimes mix quite happily, as shown by ringing studies. The Blackpool population appears to be an exception though, not that long ago it was at around sixty birds, now it appears to have halved.

I’ve read that one of the reasons the numbers are dwindling is that the goslings fall easy prey to the Herring Gulls that nest on the nearby hospital roofs. I overheard a talk whilst doing the count saying that the sea lion area will be covered as part of improvements, to enable Inca Terns to be part of the exhibit and keep the gulls out. It’s therefore a bit ironic that like the Inca Terns the Herring Gulls are threatened and of conservation concern.