Wednesday, 30 June 2010

Guess what?

Can you identify what we caught on our camera trap the other day? Post your answers below...

Tuesday, 29 June 2010

Distractions...

After a frustrating night of mist-netting last Tuesday night (update on that to come when Newton gives me the photos!), Wednesday got off to a great start. While enjoying a morning cuppa on the steps of the bothy, I suddenly spotted a brief glimpse of an otter scoot over the rocks beside the pier. We waited just a few moments and, sure enough, its head appeared above the surface of the water in the Ham. We watched it earnestly as it made a couple of short dives under the water, each time reappearing at the surface and looking in our direction. We were sure it wouldn’t hang around for long; both times I’ve spotted an otter before from here, the animal has shown briefly, but then made a sharp exit as soon as it became aware of us at the top of the beach.



However, this time, breakfast was obviously more important and we watched as the otter made several short dives, after some of which the animal appeared triumphantly with a fish in its mouth. We tracked it as it fished, making its way slowly out into middle of the West Ham, until it appeared at the surface with the rear end of a substantial fish in its jaws. With a big meal to consume, the otter swam speedily to the south side of the Ham and climbed out onto the rocks, where it proceeded to devour its breakfast (or maybe lunch...we - nocturnal storm-petrellers - are probably on a slightly different timescale to otters!) in front of us.


When the excitement subsided and the otter moved off, we thought it was about time we started some work. Back in the bothy, we cleared up after breakfast and got together our gear, when I then spotted a Great Northern Diver in the West Ham. Probably the same bird that had been in the Ham yesterday morning, the bird is not quite in full breeding plumage, but still a very smart and beautiful bird. And so, our attentions were turned away from work for a little longer...

Photos to come soon!

Monday, 21 June 2010

Latest sightings

Great Northern Diver in West Ham this morning.

Sunday, 20 June 2010

Aalamootie update

The stormies (aalamooties) have started laying! The first incubating bird was confirmed in a study nest site this week! Quite possibly there are others in study sites that have laid eggs, but it’s not always easy to see an egg beneath a bird. They are quite sensitive to disturbance during incubation, so visual inspections of nests are done infrequently and, once an egg is confirmed, a nest will not be disturbed again until close to the expected hatching date.



This news comes as a relief after the previous week, during which a number of fresh, dead eggs had been found. The eggs are incredibly fragile and can easily be damaged by the birds themselves or by the coarse substrate which the birds so often lay their eggs on – on shell sand in the boulder beach or stony ground in the stone walls.


A dead egg found just outside of a nest site, probably kicked out by a bird within.
You can see it is very fresh, since there is still yolk inside. (Hannah Watson)  


Like all petrel eggs, those of a storm-petrel are pure white, with no markings. As you can see, they are very small - less than 3cm - though, pretty big compared to the size of the actual bird. In fact, the storm-petrel lays the biggest egg relative to its body size of all birds! Given this, it will not be surprising that a female storm-petrel lays just one egg, which reflects a huge energetic investment.

An abandoned egg found in a nest site on the boulder beach - a small crack is visible
on the far left, so the egg will no longer be viable. (Hannah Watson

Friday, 18 June 2010

Introducing the wildlife of Mousa

While the aalamooties (storm-petrels) may be by far the most abundant of all the wildlife on Mousa, they are far from the most apparent or commonly seen....

Many of the shag (scarf) chicks are now almost as big as their parents. Last week, in their thick black coats, they were sweltering in the warm (it’s all relative!) sunshine.

An adult shag and its chicks fanning their gular pouches, desperately trying to keep cool (Dan Brown)

The brown, but elegant, plumage and an amazing ability to remain seemingly motionless has kept this female eider (dunter) so amazingly well-camouflaged, that most people haven’t even noticed her, despite being sat on her nest within a metre of the footpath!

Spot the duck (not the dog)! (Hannah Watson)

Today, she was nowhere to be seen, leaving an empty nest lined with a dense and cosy coating of down. I hope her and her family made it to the water safely!



Having returned from spending the winter (or summer, rather) in Antarctica, the noisy Arctic terns (tirricks) can be seen feeding along the shores, beaches and freshwater lochs.

 An elegant Arctic tern (Dan Brown)

Though late in the season, a few tirricks have finally settled onto nests, though less than 50 birds appear to actually be on eggs. This doesn’t bode well for the Arctic skuas (skootie aalins), which make their living as professional kleptoparasites, robbing fish from tirricks coming in to feed their young. Spectacular aerial displays are performed, as the aalins persistently harass tirricks until they have successfully stolen a single sandeel from them. While one might feel sympathy for the poor terns, Arctic skuas are rapidly declining in the UK. 8 pairs bred on Mousa last year and 7 chicks were successfully raised between them.
A dark morph Arctic skua in flight (Dan Brown)

Away from the coast, you can’t go very far without risking attack by great skuas (bonxies). One pair, nesting close to several storm-petrel study nests, seem to have taken a particular dislike to me!
Full frontal attack from a pair of irate bonxies (Hannah Watson)

They are ferocious predators and undoubtedly fill the niche of birds of prey up here in Shetland. Due to their impressive size and typical soaring flight, a bonxie could easily be mistaken for a raptor in flight, at first glance. We have found evidence of bonxies eating all sorts of things here on Mousa, including starlings, storm-petrels, fulmars and a wigeon.

 A bonxie enjoying a morning stretch (Dan Brown)

Fulmars (maalies) occupy nest sites near the top of cliffs or on the ground along one of the many stone walls on the island. Their primary means of defence and protecting their nests is projectile vomiting fatty, fishy oil! This one was keeping me company while I ate my lunch on the bothy doorstep.

Inquisitive and unafraid fulmar (Hannah Watson)


One might think the pair of red-throated divers (rain gös) have habituated to humans, since they decided to establish their nest right beside the footpath. Typically highly sensitive to disturbance during the breeding season, the footpath was subsequently immediately re-routed, keeping people at a distance from the divers. And rightly so, as I observed today the result of people having complete disregard for the signs, clearly asking visitors to follow the re-routed path: the divers rapidly left their nest and were anxiously paddling around the loch! Fortunately, one of the pair returned promptly to the nest, once the people had passed.

Sunday, 13 June 2010

The short Shetland summer nights

At this time of year, the stormies are just returning to their breeding colonies, having made the long journey north from their wintering grounds (or ‘waters’, perhaps being the more appropriate word!), probably somewhere far off the coast of West Africa. Due to their small size, they are highly vulnerable to predation; consequently, they only return to the colony under the cover of darkness and nest in the relative safety of the numerous cavities in the dry stone walls, boulder beaches and in the broch itself. Consequently, it is to be a nocturnal lifestyle for storm-petrel researchers.



The sun slowly descends in the sky as we patiently wait for darkness


Each evening, we eagerly wait for darkness, anxious to see and hear the stormies flooding back into the colony, either to take up occupation of an established nest site or in search of a suitable site and the perfect mate. Frustratingly though, at this time of year, at such high latitudes, darkness arrives late each night and doesn’t hang around for long. Depending on the extent of cloud cover, some nights it never seems to get that dark. You can certainly get around without the need for a torch (or ‘lamp’, as they call them here in Shetland) even when there is some cloud cover.


European storm-petrel in the hand


Some time shortly after 11.30pm, as darkness takes over, one-by-one, the birds slowly begin to appear, their silhouettes clearly visible against the dim backlight of a Shetland summer night, as they whizz back and forwards. One could be forgiven for thinking they were bats, for the speed and nature of the storm-petrel’s flight, their small size and almost totally black plumage, is not so dissimilar. Though, there are no bats in Shetland. Maxim Gorky, the Russian writer, described the flight of the ‘stormy-petrels’ like ‘a streak of black lightning’. As the darkness intensifies, the purring and chattering of the storm-petrels increases in volume, as more and more birds join in the cacophony. The purring is relentless, except for the breath note taken every couple of seconds, which sounds much like a hiccup. Song is frequently interrupted by numerous chatter calls – a rapid series of harsher notes of variable pitch. With skilful use of your ears, you can identify a pair in a nest and eavesdrop on their exchange of purring and chattering. Dan made some great recordings last week, but haven't figured out if I can upload one here yet...


Typical nesting habitat of stormies - almost impossible to find them at times!


Birds can maintain this constant song for hours on end, though, here in Shetland, are largely restricted by the short periods of darkness. Before the sky begins to get brighter again, there is a period of brief, mass exodus, as birds depart their nest sites and whizz back out to sea, reaching probably at least 150km offshore before the sun has risen. Not all birds leave the colony before light, remaining in their nest for the duration of the day. Some of those birds will produce occasional bursts of song during the day, but the majority keep quiet until darkness comes again. There appear to be significant numbers of birds that are remaining in the colony during the day, which perhaps an indication that food supply is plentiful, such that they don’t need to head back out to sea to feed every day. Fingers crossed this bodes well for a productive season...

Friday, 11 June 2010

Sailing through the fog

Having successfully negotiated a Land Rover and caravan through the streets of both Glasgow and Aberdeen (thank you, Mark!), we were first to roll on to the ferry (fortunately they didn't make us reverse on!) and we set sail for the Shetland archipelago, exactly 3 weeks ago. Rolling off the ferry into Lerwick, 12 hours later and just after 7 in the morning, we embarked on a whistle-stop tour of the south mainland, calling in for coffee and introductions to all the people, dogs and freezers which will all be key to the success of the project! Having picked up the last-minute essentials of bird rings, water and UHT milk, by 1pm we were aboard the boat and headed for our final destination - Mousa.

With the Solan IV laden with our gear, we were ready to set sail (Mark Bolton)

Only a 15-minute sailing from the mainland, Mousa is, in many ways, easily accessible; however, its lack of inhabitants, any proper dwelling (with an intact roof at least!) or facilities and the frequency with which bad weather prohibits sailings, makes it feel quite remote. As, first the island, then the broch, slowly appeared through the dense fog, I knew that Mousa would prove to be a truly magical place.


Approaching the western shore of Mousa (Hannah Watson)

The 450-acre island lies off the east coast of the south mainland. It is famous, both historically, for its 43-foot high Iron Age broch (the most preserved example in Scotland), and ecologically, for its spectacular wildlife. Of particular note is the species that is the focus of this project - the European Storm-petrel (Hydrobates pelagicus), which return to Mousa to breed during the summer months. Storm-petrels, more affectionately known as 'stormies', are small seabirds which spend most of their lives far out at sea. They are nearly all black with a white rump and subtle pale bar on the underside of the wings. If you saw one at sea, you could be forgiven for thinking it was a house-martin, given the uncanny resemblance. 

A stormie at sea off the west coast of Ireland (Dan Brown)

Mousa supports the largest colony of storm-petrels in the UK and is though to hold almost 12,000 breeding pairs! That equates to at least 40% of the UK population and more than 2% of the world population. While the colony on Mousa seems to be doing very well and has been increasing over the last 20 years, colonies elsewhere in the UK are displaying quite opposite trends, with significant declines in numbers. Studying the storm-petrels on Mousa will improve our knowledge of this poorly-studied species and contribute to our understanding of the drivers behind such variable population trends at different colonies.

The fog rolls back and Mousa emerges in the sunshine (Hannah Watson)

Only a 15-minute sailing from the mainland, Mousa can be reached on Tom Jamieson's boat (www.mousaboattrips.co.uk or 01950 431367), which takes visitors over to the island every day between mid-April and early September (weather pending, of course!). On Wednesday and Saturday nights, Tom also operates trips to see and hear the stormies as they return to the colony at night, having spend the day feeding way off shore.