Cold snap fails to deter wintry visitors or locals
DESPITE the wintry weather, with sub-zero overnight temperatures, there were still a few small migrants around in the last week of November.
The coal tit is continuing its residency at Sandgarth, Voe, along with a robin and a brambling.
There was a waxwing at the Sletts, and a robin, a grey wagtail and a pair of stonechats around the area of the Shetland Catch factory in Lerwick while a black redstart was at the West Voe of Sumburgh.
A long-eared owl was roosting in the trees in a friend’s garden on Bressay, giving him a slight surprise when he came out of the house, as he met its fierce stare.
My friend was also surprised to find a small fish in his garden, presumably dropped by an unlucky seagull, so he brought it along at the weekend for identification. About 15cm in length, it was a greyish-brown with lighter blotches on its underside. It had a large, flattened head with bony crests and blunt spines, large pectoral fins and smaller pelvic fins with sharp spines on the gill covers.
Its scientific name is Myoxocephalus scorpius, known as the bull rout, short-spined sea scorpion or fatherlasher. This fish is related to the scorpion fish which has poisonous spines on its dorsal fin but it is not poisonous although its spines can inflict a painful wound.
The bull rout, which can grow up to 30cm, is widely distributed along the North Atlantic coasts and is common in shallow-bottomed seas and estuaries.
The bull rout features in a survey of otter diets in winter in Shetland, but the favoured winter prey is butterfish and rockling. On Sunday morning, while walking along an area of coastline, I was rewarded with some fine views of a dog otter fishing just offshore.
Time after time he dived under the cold, grey waters and surfaced with prey, which was eaten at the surface. When eating, he held his head well out of the water and, occasionally reared much of his foreparts above the surface, his creamy throat patch gleaming in the weak sunlight.
Swimming in cold water uses up a lot of energy and the colder the water, the greater the energy expenditure. Otters can spend several hours a day foraging, and if prey is scarce, they spend longer in the sea, thus using up more energy, and getting colder, resulting in higher mortality.
At this time of the year, otters live very much on the edge and I was relieved to see this otter foraging very successfully in the biting cold.