Natural Selection

I’m not doing myself any favours today with my choice of topic. I’ve watched an Osprey catching a fish at close range only a handful of miles from my childhood home, something I’ve meant to get round to since they colonised south west Cumbria. I’ve also been mesmerised by swarms of Sand Martins appearing over lakes both sides of the Lancs / Cumbrian border today, seeking refuge in the sudden downpours and highlighting the fine margins of migration.

But I’m going to write about hybrid geese. Partly because I have pictures, if you want to see Osprey images from Furness you don’t want to see them off my mobile phone. But it’s also interesting to me. The geese at Park Farm were once part of a wildfowl collection belonging to a previous owner. They are now feral, and the Barnacle Geese have been getting very familiar with Canada Geese. Of over twenty Barnacle like geese you could count on one hand the number that were pure.

If you are thinking the bird above looks superficially like a Canada Goose given the face pattern then you’d be right. But it’s otherwise Barnacle Goose like in structure and size, and has a largely darkish breast where a Canada would generally be paler. Below is another individual.

This one is even darker in the chest. A ‘Cackling Goose’ small form of Canada would be predominantly chestnut towards the rear not monochrome like this bird which clearly has a lot of Barnacle Goose in its ancestry. I have video of this bird calling, and to all intents and purposes to the naked ear it sounds like a Barnacle Goose not a Canada.

Most of the birds were miles away on the opposite hillside. They were also quite scattered, but this picture of three of the hybrids shows how Barnacle like they are in terms of structure. The fact that they are dwarfed by the Canada Goose and Greylag in shot suggests the Canada parentage is likely to be of one of the smaller forms more popular in captivity.

Apologies to anyone offended by the assigning the term Carbuncle to these birds, which starts with ‘Ca’ from Canada and ends with ‘cle’ from Barnacle whilst also being somewhat disparaging. I do find it interesting to see these hybrids though and it isn’t meant to be offensive.

As I may not blog for a while here are a couple of bonus swans from Ormsgill Reservoir, Barrow today.

LI6 – ringed on the rezza as an adult male in August 2012. So he’s a reasonable age for a Mute Swan.

Y356 – ringed as a female cygnet in September 2019 in Sheffield. Not sure how she got to Barrow but she’s been resident for over two years now.