Craig Nisbet is one of the seasonal rangers working on our Noss National Nature Reserve in Shetland. Today his blog post looks back on July, a particularly active month for the seabird colonies on Noss. Already he has had to say “good-bye” to a few new residents as they set off out to sea from the cliffs.
Guillemot chicks spend very little time on the cliff. As soon as is possible, they become jumplings; unable yet to fly, but capable only of the daunting leap of faith, following the encouraging calls of their father. Those that survive the intimidating plunge, are quickly led out to sea by their fathers, away from the predation threats closer to land, where they’ll spend as long as three years, before reaching maturity and returning to the sea cliffs to breed themselves.
A more leisurely breeding strategy is adopted by other seabirds. Gannets have been holding territories since April, and their chicks are growing slowly but surely, into large fluffy nestlings. In many cases the adults are eventually pushed to the side of the nest to allow the chicks enough room as they grow into large flightless birds. They will eventually have to take to the wing, but unlike the guillemots, they should be able to make their first flights from their nest sites, hopefully avoiding the long drop to sea.
Fulmars have been incubating single white eggs for many weeks around the island, and early in July the first chicks were seen. Soon afterward, it appeared that there were fulmar chicks on every cliff; miniature versions of their parents, with the ability to project a foul smelling oily substance toward potential intruders.
The lower levels of the cliffs are occupied by nesting shags. Often tucked away in caves where they are safe from predators, surveying the population can present a challenge and requires boat monitoring work in suitable sea conditions.
The last all-island shag count revealed a minimum of 67 nests, with young either in or near their natal sites, observing the activities of adult shags gathering on rocky headlands at sea level.
Elsewhere on the island, skuas inhabit much of the grassy moorland, and their young chicks have begun to wander from their nests, as many gull chicks do. The more abundant bonxie (great skua) is found across the island, with scootie alans (Arctic skuas) being marginalised on Noss, to the outer fringes.
The demise of the latter is a sad story locally, but Shetland represents a stronghold for bonxies, whilst the Arctic skua population is relatively stable elsewhere. Both chicks bare little resemblance to their adult form, but both will grow to become opportunistic predators and scavengers. The Arctic skua is often referred to as the pirate of the seabird world, for its persistent pestering of the next species- the tirrick, or Arctic tern.
The relative success of the tern colony on Noss this year indicates good availability of a key food source to many seabird populations- the sandeel. None hatched last year, but with at least 14 fully fledged chicks this year from an estimated 33 nests, we are pleased to report some success again this year.
The adults will soon, set off for their long migration south, where they’ll chase perpetual sunlight all the way to Antarctica. But for now, they are keen to encourage rapid growth of their fledglings in the hope that they too will have the strength and ability to follow them on their epic journey.
Another significant change on Noss is the arrival of our new warden Andy Denton from the Farne Islands in Northumberland, as we bid farewell to Katherine Snell after two-and-a-half seasons. Andy’s experience from working on Farne Islands continues a tradition of wardens moving between the two seabird colonies. His first contribution has been to establish a new Gungstie stick tree, which he hopes will become a haven for passage migrants as the autumn migration season approaches, in the absence of any actual trees to provide significant cover.
The new Gungstie stick tree is, I’m sure you will agree, a masterpiece in tree construction!
To find out more about Noss National Nature Reserve visit http://www.nnr-scotland.org.uk/noss/%5B/embed