Last week began quietly for North Isles wildlife, but gathered a little pace as the week progressed. The most interesting birds were 10 crossbills seen at Baltasound last weekend, preceded by a male in Haroldswick.
Breeding right across Europe and beyond, wherever there are conifers, those occurring in Shetland come mainly from Scandinavia. Crossbills are eruptive birds, sometimes arriving here in huge numbers if food sources run low in their breeding areas. Only time will tell if this is going to be an eruption year. They breed in the earliest part of the year, sometimes surrounded by snow as they incubate the eggs. However, in years when food supplies run low, they move out and those arriving in Shetland have, in the general absence of conifers, to feed on whatever seed sources they can find, many probably succumbing to starvation.
The first summer Iceland gull reappeared at Norwick last weekend along with a great northern diver, probably also a first-summer bird with no sign of summer plumage. In fine summer plumage, however, was another in Burrafirth last Monday. Two quail, one in Fetlar, the other a long-stayer in Unst, were heard during the week. Fetlar’s red-backed shrike remained at Funzie.
But with the euphoria of spring migration just about over, last week was a time to catch up with breeding bird surveys. Undertaking one on Lambaness, young oystercatcher and very small lapwing were noted, while it was good to find a pair of ringed plover appearing to have young. Recently fledged wheatears were around, while both meadow and rock pipits were busy carrying food to unseen nests. Several more broods of young eiders appeared around the coast, though alas there are a number of predators awaiting the chance to dine on them.
The first ghost moths of the year at Burrafirth began appearing in the trap last week. Males of this, the largest member of the swift moths, have both fore- and hind-wings plain white, though the subspecies thulensis occurring here are slightly darker and smaller. Females, meanwhile, have distinctively yellowish forewings with darker markings. The name comes from their characteristic display flight at dusk, sometimes involving several males, during which they release a specific scent to attract the females in. The food plants for the larvae include the roots of grasses and other small plants.
Last weekend proved a lively one for killer whales in the North Isles, fortunately witnessed by Andy Foote and Volker Deecke of the Scottish Killer Whale (Orca) Project who could individually identify them. Different from the pod of five seen in the area several times this summer, this group of four, made up of two adult females (one of which was previously photographed off Iceland), a male estimated to be between 13 and 14 years old with dorsal fin just starting to grow larger than those of the females, and a 4-5 year old juvenile, had not been seen here since August last year.
Andy and Volker witnessed them make a concerted but unsuccessful attack on an adult grey seal which made it ashore, while they followed them along the east side of Yell until they subsequently headed for Lunna Ness. They were also able to listen to the orcas under water which were, as expected, more or less silent as they hunted, apart from a few echolocation clicks. This whole episode was witnessed thanks to a phone call to the team received from Cullivoe and a timely reminder that if you see any orcas, please get in touch as soon as possible on 07500 380524 – you might be contributing to a little more knowledge about these enigmatic creatures.