Thursday, 27 February 2014

Beachcombing & The Polish!

I love getting down to the beach after a good storm and this winter I pretty much could have gone to the beach everyday and found loads of bits to sieve through. It always amazes me the variety of things that was up yet you hardly ever seen anything coming ashore.

When I started beachcombing as a kid I always wanted to find a Goose Barnacle Lepas anatifera in my Collins Guide to the Seashore they looked amazing and I always checked all the driftwood that I found just in case there was a few stuck on the other side. I had imagined turning over a lovely sea-sculpted piece of driftwood, low and behold I was somewhat let down when the first Goose Barnacles I found were smothered around a television! It was the most beautiful TV I have seen though!

Goose Barnacle - Lepas anatifera
Up close they are stunning animals but I still can't believe that in the past they used to think that Barnacle Geese grew out of these little chaps! There wasn't much else washed up and I couldn't find any dead birds when others had been finding lots. I am not sure if that was a good sign or whether the gulls had already cleared up any scraps along the strandline.

Polish Mute Swan - Cygnus olor immutabilis
Next stop was a quick scoot around Princes Park to see if there was anything unusual. The only thing I found of not was a 'Polish' Mute Swan. The Mute Swan above shows all the characteristics the unusual colour form called 'immutabilis', also known as Polish Swan. The mutation is sex-linked and recessive, and occurs in a gene located in the Z sex chromosome. Unlike most mammals, female birds have two different sex chromosomes (ZW), while males have two of the same kind (ZZ). If the female has the mutation, she will be white as a cygnet and will moult into an adult white plumage directly. A male needs to have two mutated forms of the gene to be a Polish Swan.

When a Polish Swan is a cygnet they are covered in totally white down as opposed to the usual grey down which Mute Swan cygnets are covered in. Gradually when they reach adulthood they lose all traits of being 'Polish' except for the colour of their feet.

Polish Mute Swan - Cygnus olor immutabilis

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