The latest count of incubating Arctic terns on Mousa is 925! This is more than double that of last year. In years past, at this time, I've been feeling cautiously hopeful about breeding success but my hopes have been dashed when the sandeels appear to disappear and chicks starve. But this year, I am more hopeful than ever before. There's been such a series of poor breeding seasons, with few or any Tirrick chicks fledging on Mousa and you may have read or heard the recent articles about the effects of many poor breeding seasons on the population of various seabirds. Tirrick is the local name for Arctic terns, taken from the sound they make as the chase off a person, sheep or any perceived threat that is too close to its nest.
This year, it appears that there are loads of fish available, so I am most optimistic. Tom (the ferry man) has never seen such a quantity of birds feeding in the Mousa Sound for a long time, commenting that the sea is quite white with birds. For not only are there terns but gannets are plunging (feeding on mackerel), and large groups of great black-backed gulls are congregating, feeding close to the surface (on what? I don't know). It is worth noting that the sea is rather an unusual colour, caused by an algal bloom. The sea is that shade of green you see in photos of tropical shores. This bloom has drawn in a large rare visitor to our shores, which was spotted by one of the groups on our Mousa Open Day on Saturday. The fotunate few were delighted to get views of a basking shark - a formerly common fish in these waters, but less so in recent years. The dorsal fin and tail fin both protrude above the sea surface, and thus can give you an idea of the size of this enormous fish.
A group of more commoner sea creature visited the sea off Sumburgh Head on Friday - killer whales! I am pleased for the folk that saw them, but Linda (Field Teacher) and I were on Mousa at the time taking a school group around as a part of our Living Classrooms educational service. Och well, can't be everywhere at once! Our post of Field Teacher is quite a recent one (thanks to funding from public support, Chevron and Scottish Natural Heritage), and I am so pleased that we have Linda. Not only is she an ex-headteacher with years of teaching experience but she is also a keen diver with a broad knowledge of marine life. Linda led a rock pooling trip on our Open Day, and some of her dive buddies came along to access some deeper water. It's great for children (and adults!) to discover marine life - hermit crabs, anemones, chitons, corals, seaweeds, shrimps, starfish, brittlestars, top shells, thingimmyjigpods with bright yellow knees and a habit for hanging upside down on seaweeds... When people are more aware and understanding of life that is in the seas around us, it leads to better appreciation and hopefully more action to help conserve these amazing habitats and sealife.
I hope to give you an update on what's going on with the seabirds at Sumburgh Head in the next blog, thanks to Martin Heubeck (of Aberdeen University/SOTEAG). Also, Rob will be checking puffin burrow activity this week, so I can tell you a bit about our Tammie Nories.
Cheers eenoo
Helen