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An interesting skull from a friend


The week before last, fellow bone collector Ric Morris came to my house for dinner with his wife and his daughter. They were on their way back from their holiday in the highlands and islands, where they went beach combing. Dad made made a lovely meal for all of us earlier that day.

After dinner, he told me that he had brought some skulls that he found on the beach for me. We went outside and he showed me the bones he had found. Most of them still had dried flesh, but one or two were clean. One of them was a skull - let's see if you can ID it. Here are some clues:

The skull is 125mm long and 20mm high. From its shape you can tell that it is a bird. They are about the size of a goose and they can grow up to 78cm tall and they have a wing span of 1m. The skull has muscles at the back of the skull to keep the head balanced whilst in flight and the brain case is big compared to the skull. They rarely come inland and they feed out in sea. They can dive up to 45m below the surface. It is smaller and slimmer than the gannet skull, with a steeper forehead. Its long beak with a hook at the end is what is uses to catch its food.

If you still don't know what it is, I'll tell you. It's a shag skull ! Shags (Phalacrocorax Aristotelis) are all-black birds that eat mostly fish and sometimes small insects. There are believed to be around 27,000 pairs in the UK. They are in the family Phalacrocoracidae, which was the family of shags and cormorants. This shag is at the Scottish Seabird Centre in North Berwick, and you can see the yellow at the base of the beak and the crest on the top of his head.

Shagss are very similar to cormorants, which I see a lot of. The differences between them are that cormorants are much bigger with a heavier, thicker beak and shags have a crest on their head and they have a yellow and white patch where the beak meets the face.

During their breeding season, the best places to see them are Shetland, Orkney, and the Inner Hebrides. They are also found around the coasts of Cornwall, Devon and Wales. During the breeding season, they develop a green tinge to their black feathers and that's when they develop the crest on their head to attract mates. When this season stops, their feathers go duller, they lose their crest and the yellow patch which is their all year, gets more yellow. The thick ridges on the back of the skull are the muscle attachments to keep the head balanced.

The breeding season is long, beginning in February but some nests are not started until May. Most of the time, three eggs are laid, but the chicks hatch without feathers that keep them warm, called down. They are in the nest for around two months before they can fly and fledging occurs from June to August. This shows the entrance of the brain case.

They make their nest from sticks, seaweed and other debris that they can find. They make them on the edge of cliffs beside the sea, some over 100m above the water. These nesting areas have loads of nests because they are social animals that like to live together. They also have the same mate for life and they use the same nest for years. Juveniles are brown where the adults are black, but they have a white neck. It is very rare to find a bird skull with the hyoid process ( the bones that move the tongue ), but this skull did not come with those.

Their threats are entanglement in fishing nets, and can be shot, poisoned or drowned by fish-farm owners as they could eat their fish. They can also be affected by the Newcastle Disease, which was a disease that affects birds. It was transferred through a sick bird to a healthy one. If human were exposed to these sick birds, we would get conjunctivitis, but that was it. Birds on the other hand, get water diarrhoea, muscle tremors, their wings droop, their egg shells are thinner, so the chicks have less chance of survival. The worst symptoms are full-body paralysis and even sudden death.

If you look at the picture below, you can see a line at the end of the beak, where it flexes.

Thanks Ric for giving me this skull and all the others that I will write about at a later date !

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