Thursday, 23 September 2010

Latest sightings

All had been pretty quiet on Mousa until the Brothers Fray kindly found a Hornemann's Arctic Redpoll behind the bothy on Monday. Photos courtesy of Richard Fray...

Golden Plover is the only other new addition to the Mousa bird list for this season, with one lone bird present on Monday. With only one more brief trip to Mousa lined up for this season (weather pending, of course), here's hoping something of interest turns up. And, that I haven't got my head stuck in a hole in the wall at the time! 

Tuesday, 21 September 2010

Stormie September

What was supposed to be just three days off Mousa, allowing a fleeting visit south for a wedding, turned into two weeks' (unwelcome) holiday from fieldwork. I had been warned that the weather is notoriously unpredictable and poor in September, so perhaps I should have known the risks of leaving the island, but I had been deluded by some of the best weather of the summer in the first few days of the month. The shorts even came out for just the second time all summer! After 16 weeks in the field, the enforced break did at least offer a touch of showers more than just once a week, a kettle (much quicker means of making tea than boiling water on a stove!), no draughts coming in under the doors, fast internet, a sandy beach to run around on.... However, it did interrupt the regular monitoring of growth of Stormie chicks and I was left hoping that none would fledge before at least another set of measurements, and blood and feather samples could be collected from them.

Stormie chick tucked away in a nest site at the base of a dry-stone wall

Finally, the winds eased on Saturday, allowing the boat to comfortably cross Mousa Sound and moor safely at the jetty. A check of all study nests revealed just 3 out of 44 chicks had fledged. All these fledged within approximately 55 days, towards the lower end of the highly variable development period, which can range from 50 up to more than 70 days. The majority of chicks won't fledge until well into October. Most eggs that were still being incubated at the beginning of September have now been abandoned or the chick died within just a few days of hatching. Perhaps these late breeders are inexperienced birds? Are they just practising? Going through the motions of incubation but never with any intention of seeing it through to hatching or rearing the chick? The later a chick hatches, the harder it will become to provision that chick through the autumn.

This Stormie chick is partly-feathered, but the feathers are all still in pin (i.e. actively growing)
and a reasonable amount of down still remains

Good news is that all the chicks of radio-tagged birds are continuing to grow at a healthy pace; 3 are probably very close to fledging, while the other 3 will continue to be reared in the nest for a little longer. With no evidence of radio-tagging affecting a bird's ability to forage and provision its chick, we will look to expand the radio-tagging project next year to enhance our understanding about frequency and extent of movements of birds within the colony. A full update on the radio-tracking is to follow soon.  

Chick of a radio-tagged bird - the chick is fully-feathered with just a few tiny tufts of down remaining. With a tarsus length of 22.7mm, weighing 34.5g and with a wing chord of 109mm, this chicks must be ready to fledge virtually any day now.

Wednesday, 1 September 2010

Latest sightings

Today, an immature male Wigeon in East Ham. Yesterday, 2 Lapland Buntings on south shore of West Ham. Other sightings over the last couple of weeks include 2 Willow Warblers behind the bothy, small groups of up to 6 White Wagtails, 2 Common Sandpiper in West Ham, Green Sandpiper on the North Loch and regular sightings Grey Heron, with a maximum of 4 recorded. Within the last month, Spotted Redshank, Greenshank and Ruff have also been sighted.

Most of the breeding seabirds are long gone, with most Tysties and Arctic Skuas having disappeared from the island in the last week or so. Large groups of young Tysties and Shags are sitting just offshore every day. There are still good numbers of Bonxies hanging around, Fulmars are fledging and, of course, Alamooties (stormies) are still breeding. Most are now rearing a chick, but several are still incubating. Wheatears, Snipe and Skylarks seem to be everywhere, along with several small flocks of Twite. Along the shoreline, there are lots of Redshank, Turnstone, Ringed Plovers and Oystercatcher with regular sightings of Knot.   

Saturday, 21 August 2010

A fortuitous date with Risso's

Having fled Mousa on Thursday afternoon due to the severe weather that was forecast, I was relieved to wake up to a bright, calm and even sunny (!) morning on Friday, enabling a return to Mousa. However, I rapidly began to get anxious and frustrated, when, having arrived at the boat for a 10.30am departure, we were still sat on the boat at the pier after 11am waiting for a cruise-boat load of tourists to arrive. Fortunately though, this turned in our favour as news came in of a pod of Risso’s dolphins in Mousa Sound making their way north – in our direction. Having just received a call to say the tourists would still not be there for another half an hour, Tom, the Mousa Ferry operator, very kindly took us out into the Sound in search of the pod. Within just 5 minutes, we had spotted and caught up with the animals. There were between 20 and 30 individuals, including at least 3 calves. It was hard to tell quite how many there were in total as they were all quite loosely aggregated across a wide area. We observed several individuals half-breaching out of the water and some tail-slapping too. All in all, it was a stunning display and more than worth a belated return to Mousa. Thanks very much to Tom, and his right-hand man Willie, for taking us out to enjoy these spectacular animals in such a responsible manner.

Adult Risso's dolphin with calf in Mousa Sound (Rob Fray)

Radio Gaga

Due to the challenges associated with studying birds that only return to land at night and nest out of sight in cavities, we know little about the extent and frequency of movements of breeding birds around the colony. Do birds fly directly to their nest-site on return to the colony? Or, do they range more widely throughout the colony? Storm-petrels typically undertake incubation shifts of 3-5 days’ duration and, it is assumed during this time, the off-duty partner remains far out at sea, foraging; however, might birds sometimes forage more locally and return to the colony on nights when change-overs do not occur? When incubating an egg or brooding a chick, does the bird ever leave the nest during each shift or does it sit tight for that whole time?

Radio-tags have been deployed on 6 adult birds in a trial project to help to start to answer some of these questions. Radio-tags consist of a small battery (10x4x3mm) with an attached antenna. Each tag is programmed to emit a radio pulse at a set frequency. By attaching tags of different frequencies to different birds, individuals can be detected and recorded using aerials mounted on posts within the colony and automated recording units. The units constantly search for the frequencies of the 6 tags that have been deployed; when one is detected, this is recorded, along with the time and date and signal strength, which is relative to the distance the bird is from the tracking system.

Radio-tags - the aerial on one has been cut down to a reduced length, ready for deployment on a stormie

The remote recording unit is attached to a power supply and an aerial (Biotrack Ltd)

Each tag weighs less than 0.6g and was mounted at the base of the four central tail feathers using Tesa© tape. A tag of such a small size will have minimal impact on the flight capability of a bird. The aerial was cut down to less than 7cm reducing any chance of snagging on rocks and limiting the detection range of a tag to less than 100m from a recording unit. Following repeated contact with salt water, the tape will gradually lose adhesion and detach over the course of a few weeks.

Attaching a radio-tag to the tail feathers (Hannah Watson)

Tags were deployed to birds whose nest locations are known, allowing us to monitor chick growth rate and subsequent breeding success to verify that the tags do not have any significant impact on birds. The current aims are to trial the equipment, determine how long tags last for and verify that there are no significant effects of the tags on birds. Next year, it is hoped that more tags will be deployed earlier in the season, during incubation, to obtain more detailed information about patterns of movement of breeding stormies within the colony.

Stormie with radio-tag attached (Hannah Watson)

Tuesday, 17 August 2010

A slight diversion...

A rare sighting was reported, this weekend, of a storm-petrel researcher, not only leaving the island of Mousa, but venturing further north than Lerwick! Two lovely days were enjoyed exploring the isle of Unst, the most northerly part of the UK. Unfortunately, I didn’t reveal any rare sightings of my own, not that I was really trying very hard at all, but a leisurely time was had involving a spot of botanising at the Keen of Hamar, marvelling at thousands of gannets at Hermaness, eating garlic-soaked langoustines and dipping cafes and brewerys. Sightings were limited but included Edmonston’s Chickweed, 2 Great Northern Divers (one in stunning summer plumage) and a sleeping otter (which my mum almost stood on!) on Ham Beach (by Muness Castle), 25+ Ruff feeding in fields around Muness Castle, and 1 Black-tailed Godwit on beach on Uyeasound.

Mousa escapee

Keen of Hamar

Slender St John's Wort Hypericum pulchrum

Edmonstons Chickweed Cerastium nigrescens, endemic to Unst

Field Gentian Gentianella campestris

Hermaness - the UK's most northerly nature reserve

Muckle Flugga - home to the UK's most northerly lighthouse - and just a few gannets on the adjacent rocks

Sundew Drosera rotundifolia

Peacefully sleeping otter, Ham Beach, Muness

Sunday, 15 August 2010

Joke of a July

Wet and wild...that pretty much sums up July on Mousa. So much for it being summer. And, everyone keeps telling me how wonderful last summer in Shetland was. Funnily, that doesn’t make me feel any better. While this has not necessarily affected data collection, it has made work pretty miserable at times. Very few additional nests were added to the study sample since the end of June; when you rely on sound to find nests, relentless wind and rain is somewhat of a impediment.

North-easterly winds and relentless rain pound the east coast of Mousa 

Unsurprisingly, much of July was spent holed up our small stone bothy – the only means of shelter on the island. And, what else is there to do but much on crisps, chocolate and cheese (the foods of choice on Mousa) and warm the red wine on the stove (it’s far from ideal drinking temperature otherwise).
Another consequence of the atrocious weather has also been long stints on the island without a break and days on end without seeing another soul. It’s a good thing the stormie “team” (this term used loosely since it’s just the two of us) get on so well and share the same tastes in food, drink and music. Tom, the ferry operator, might expect to lose a couple of days here and there due to weather in July; in the first 17 days of the month, however, he only made it over on 7 of those days. Things picked up a little bit in the latter half of July, but there were still many days where the weather prevented him from making the journey over.

Making the most of it...huddling in the relative warmth and comfort of the bothy, with a beer in hand, 
while gazing out into the fog

When we finally made it off for just a day and a night, it was such a rush to get back that we managed to forget bread, butter and wine! Then stranded again, we feared we may have to call in the coastguard to do an emergency drop. Though, I’m not quite sure any of those items would quite constitute an emergency in their eyes.

Dark skies gather over the mainland
The tents were abandoned long ago for fear of being blown to Norway and instead we sought refuge in the bothy and have not ventured to erect tents again since. At least in here, we have shelter from the howling wind and the lashing rain. Or so we thought, until one morning I woke up in a pool of water! Perhaps someone would be so kind to come and fit some new doors to the bothy, which don’t have several inches between the bottom of the door and the ground? And, another mattress would be nice too...wink wink.

Julie wrings out the rather soggy cushions that constituted my bed!

Monday, 9 August 2010

The last 48 hours has seen us consumed by a vast swathe of midges, zero geolocators deployed on stormies (boo), 6 radio-tags deployed on stormies (hurrah), Han consume a bowl of cereal using a spoon with a 60cm-long handle (which had previously been used for removing storm-petrel chicks from nests), our first deceased stormie chick (sniff sniff), Julie tell a joke to a sheep (it didn't laugh, but I did when she recounted it - at both the joke and the tale), 1 Whimbrel, 1 otter fishing in West Ham and 2 hooded crows creating a racket at God knows what hour of the morning! And, very little case that wasn't obvious. Needless to say, we have now escaped the island for a much-needed break. An update on the radio-tagging to follow shortly...

Wednesday, 4 August 2010

A glimmer of hope

With a change in the weather today and even a hint of sunshine, I decided to take my bins out to work with me for once. The first sighting of the day was a whopping 7 tents sprawled across the grassy plain just to the north of the broch! So much for having the island all to myself, while my field assistant is on the mainland and the boat is out of the water undergoing repairs. Later, I spotted 14 kayakers hugging the east shore of the island and put two and two together. I’ve been permanently looking over my shoulder the rest of the day, never knowing who might be watching me. Aside from breeding birds, all I could knock up was the spectacular array of 5 Redshank, 4 Turnstone, 1 Rock Dove, 19 Greylag Geese and 3 Hooded Crows! Surely something a little more interesting has got to rock up sometime soon? At least Turnstone is a new one for the garden list.

Oh well, I’ve retired to the bothy with a beer, awaiting darkness and the vague possibility of a glimpse of the Aurora Borealis. I’ve heard on the grapevine that there could be a good chance of catching sight of it from Shetland tonight...

Monday, 2 August 2010

Latest sightings

It's been fairly quiet for birds and, given that the stormie team spend most of their lives flat on the ground staring into crevices in walls, the chances of seeing anything are fairly slim anyway! Knot, sanderling and dunlin were all seen on the West Pool last week (though not by any of us!) and the grey heron was re-sighted on the Mid Loch.
Cetacean sightings have been disappointingly few and far between. Though, the weather has not exactly been amenable over the last month for sea-watching. The odd porpoises are sighted with reasonable regularity and a Minke whale was seen from the Mousa Ferry in Mousa Sound last week (again, of course, none of us saw it!). Orcas have been pretty regular further north, in Yell Sound, throughout July, but no such luck down here. Still waiting to get it on the garden list.

No otters have been seen in the garden (i.e. West Ham) for a couple of weeks, but I was able to get a photo of one the last time we sighted one. Not the greatest photo, but not bad given a small lens and the typical shyness of otters.

Otter feeding on the rocks in front of the bothy (Hannah Watson)

Alamootie update

Out of 165 nest sites that were identified with singing birds in at the beginning of the season, 67 have had an egg laid in them and 25 of those have hatched in the last 2 weeks. About 10 eggs have been lost, so there are hopefully around another 30 eggs waiting to hatch. Chicks that have been left alone by the parents so far, have weighed in at between 13 and 22 g and the tarsus measuring between 13.6 and 17.7 mm long. These chicks have been between 7 and 14 days old. Since chicks don't fledge until they are at least 50 days old (and possibly even until around 70 days old!), the first chicks will not fledge until the beginning of September at the very earliest. It's certainly a long season for the stormies and anyone studying them!

Sunday, 1 August 2010

Chicks Ahoy

The number of chicks is growing daily at the moment, with typically one or two new hatches each day. The chicks are born covered in a layer of down and, unusually, replace this with a second set of downy feathers, before the true feathers begin to grow. Having two sets of down is a unique characteristic of tubenoses and penguins. The bill is well-developed already and the ‘tubes’ (nostrils) on top of the bill are a distinctive characteristic of the tubenoses.

Downy-feathered chick at about 10 days old 
 Due to the poor visibility and accessibility of many stormie nests, detecting a hatch is often not easy. The adult sits tightly on the chick for the first few days. The hatched egg shell may be visible, providing evidence that a chick has hatched. Typically a chick can be heard calling before it is seen.

Chicks are brooded by an adult for maybe 7 to 10 days; after this, the chick is left alone while both parents spend the majority of their time feeding offshore. Once a chick is left alone for the first time, the chick is removed the chick from the nest to weigh and measure it. This will be repeated every 5 days allowing us to monitor chick growth and development. The rate of development can indicate the environmental conditions that the parents or chick are experiencing; for example, slow growth may reflect low food availability or could be related to disturbance experienced by the chick in the nest.

Retrieving a chick from a nest site in a dry-stone wall

Weighing a chick
 A chick may be fed only every 2-3 nights, so its weight fluctuates dramatically depending on when it received its last feed. Weight can thus not tell us as much about growth, so, at first, the length of the tarsus (knee to ankle) is measured which reflects skeletal growth. Once the skeleton is fully grown, at about 30 days old, the feathers will be beginning to grow in and the wing chord will be measured to monitor development further.

Saturday, 24 July 2010


The first stormie chicks have started hatching! Two hatched chicks were confirmed today in study nest sites. The incubation period of these two birds was around the expected 39-42 days and there had not been any evidence of egg neglect. The chick will be brooded by an adult for the first 10 days until it is capable of regulating its own body temperature without the warmth and protection of a parent. There are several more sites where hatching is expected in the next few days. Celebrations are under way with pineapple and mint mojitos!

Tuesday, 20 July 2010

Alamootie update

Out of about 140 study sites, eggs have been laid in 56 storm-petrel nests. While high levels of daytime occupancy of nests earlier in the season suggested that foraging conditions might be good, we have witnessed a fair amount of egg neglect in the last 2 weeks. Petrel eggs are specially adapted to survive chilling and interrupted incubation is common. However, previous research in the early 1990s revealed egg neglect in approximately 4% of nests, whereas current frequency of egg neglect is over 10%. We have also found a fair few dead eggs seemingly kicked out of nest sites. This suggests birds are neglecting their eggs (i.e. leaving them alone) and, in the meantime, another bird is coming in to prospect for a potential nest site and kicking out an egg. This may in fact mean that foraging conditions are not so good as we might have hoped.

A neglected egg which when removed and inspected was seen to have a couple of small dinks in the shell (slightly right of middle), making it unviable (Hannah Watson)

Out of about 45 nest-boxes on the island that we are monitoring, so far 7 boxes are occupied by incubating birds. The nest-boxes provide a great means of studying stormies, allowing visual inspection of nests with minimal disturbance. Here’s a sneaky peak of a stormie incubating an egg inside a nest-box...

Incubating stormie in a nest-box (Hannah Watson)

Seabird update - July 2010

Sadly, it does not seem like a particularly great year for seabirds in Shetland. Arctic terns appear to have failed across Shetland; the few pairs that I reported as having settled (rather late) onto eggs on Mousa in June, have all failed. Consequently, Arctic Skuas - whose productivity is closely tied in with that of Arctic Terns (the skuas primarily forage by stealing fish from terns!) - do not seem to be doing so well. Only three Arctic Skua chicks have been recorded so far this year, from three pairs. I discovered just a few days ago, that the “mixed” pair (comprising a light morph and a dark morph) that breed close to the Iron Age broch have a large chick. While ambling along the boardwalk, distracted by the calls of stormies from the boulder beach alongside me, I was suddenly aware of a pale morph Arctic Skua virtually on my head. I looked up to see a large, mostly-feathered chick ambling (in much the same manner as myself) on the boardwalk just a short distance from me.

Arctic skua chick - most of the feathers have grown in,
but it still retains some down around the neck and head (Hannah Watson)

After taking some poor photographs (see below - not helped by the howling wind and rain) and sheltering in the broch for 10 minutes from the deluge, I returned to my task of checking storm-petrel nest-boxes on the beach (see Alamootie update), watched closely by the adult Skua who proceeded to stand just 2 metres from me, giving me the evil eye.

A protective parent Arctic Skua watching my every move while I check stormie nest-boxes
(Hannah Watson)

Fulmar chicks started hatching just over a week ago. They seem to be very synchronous this year, with a sudden burst of hatching across the island. Adults brood their chick for about the first 10 days; after this time, the chick has got a little bigger (so hopefully is less likely to be snaffled up by a predator) and is able to regulate its body temperature without the warmth and comfort of a parent to snuggle up to. Most chicks are still being accompanied by an adult, but within the next few days, more and more will be left alone at the nest, allowing both parents to forage and provision the chick at a much higher rate, allowing it to grow rapidly. Despite this however, like all other petrels, the development period of fulmars is very long and the chicks will not fledge until they reach about 57 days old!

Cute fluffy Fulmar chick...until it starts to vomit all over you! (Rob Fray)

Thursday, 15 July 2010

Frustrating finds

Studying storm-petrels, one spends much of their life like this...

Or this...

Or this...

There doesn't seem much chance of spotting anything of interest, when you spend your life with your head buried in a wall. The orcas are probably leaping out of the water, dancing around in their full glory, while we remain completely oblivious.

Nights are spent, often frustratingly, searching for nests. Breeding sites are most easily found by listening for singing birds at nights. First you locate the approximate area of the sound, then quietly you get down on your hands and knees and press you ear up to the many cracks and crevices between stones or boulders, one by one, until you can locate the exact point of the call. Then, turning the torch on, you shine it into every gap available and hope that the beam of light eventually falls upon a bird. The response of birds to the torch-light is to either shut up instantly or start alarming at you. I’ve learned that I can communicate with them by mimicking their alarm call, precipitating repeated calls from them. The continued calling facilitates finding the bird, though on most occasions, you have to give up, knowing that the bird is buried deep down in the wall or beach, far out of sight. Maybe about 1 in 8 nests are visible and, even then, quite how much of the nest site or bird you can see is another matter. And, on top of this, we are limited to a narrow window of maybe 2 or 3 hours of darkness (highly variable depending on cloud cover) during which stormies are active and singing vigorously. Ideally, we are trying to find as many accessible nests as possible, such that, later in the season, chicks can be removed from the nest site enabling us to record biometrics and monitor growth rate of chicks in relation to visitor pressure, egg neglect and provisioning rate.

Nests are then re-located during the day to further investigate visibility and accessibility and to check for daytime occupancy. This can be further complicated by things such as cheeky gull chicks obstructing entrances to nest sites!

A cheeky great black-backed gull chick hiding in the entrance to a storm-petrel study nest!
(Hannah Watson)

Where possible, temperature loggers are deployed in nests to remotely monitor adult attendance and egg neglect during incubation. This often involves tearing your hands and arms to shreds as you try to squeeze your arm as far into a crack in a wall and have to use the sense of touch alone to excavate a suitable spot to embed a temperature logger. Then you pray that the bird will lay its egg on the temperature logger. Temperature loggers have been embedded into an artificial nest cup, moulded out of clay, with the hope of making a perfect depression to entice the bird to lay its egg in. We have had some success so far and certainly some birds and eggs have been seen sitting happily on loggers. We just need to convince a few more that our clay modelling skills produce a desirable home for their egg!

A neglected egg sitting on an artificial clay nest cup with a temperature logger embedded in it
(Hannah Watson - taken on my phone, hence not very good!)

Wednesday, 14 July 2010

Latest sightings

14th July: Grey Heron on Mid Loch, then flew off north. 2 rock doves.
12th & 13th July: Several Red Admirals seen.
12th July: The pair of Red-throated Divers on Mid Loch have successfully hatched a chick.
11th July: Swallow flying around bothy. First Fulmar chicks seen, which are probably now almost a week old.

Pair of ravens still regularly being seen over the last week or so.

Thursday, 8 July 2010

Alamootie update

There has been a rush of laying this week and, as of Tuesday, 34 birds from around 130 study nest sites have been confirmed as incubating an egg! Daytime occupancy of nest sites has been over 25%, suggesting that lots more birds may be about to lay.
Typical nesting area on Mousa's South Isle, where extensive quarrying of stone took place in the past
(Hannah Watson)
Stormies breed all over the island of Mousa using cracks and crevices in the boulder beach, the many dry stone walls that criss-cross the island (remaining from the days in which crofters farmed the land), heaps of stone slabs (remnants of extensive quarrying) and in the Iron Age broch.

Inside Mousa's Iron Age broch (Hannah Watson)

Nests are checked every 5 days for the presence of a bird and evidence of having laid. Due to the nature of nest locations, visibility is often difficult and it is not always possible to determine if a bird is sitting on an egg or not. In this case, nests are visited and checked on up to 3 consecutive days. If a bird is present for 3 days in a row, it can be confidently assumed the bird is incubating an egg.

Study nest sites are located all over the island in areas subjected to varying levels of visitor pressure. Visitor movements are being recorded using beam counters and cameras. The beam counters have a sensor emitting an infra-red beam; each time a person walks by, the beam is broken and a count is made. Camera traps are being used alongside the counters to validate the data recorded by beam counters and check that sheep are not being counted too!

Camera and beam counter hidden within one of the dry stone walls
(Hannah Watson)

Wednesday, 7 July 2010

Otter encounters

At last, we can publish photographic evidence of the stunning otter that we watched fishing two weeks ago in the West Ham...

Otter gorging on the tail stock of a sizeable fish in the West Ham
(Mark Bolton)

This Great Northern Diver, not quite in full breeding plumage, was seen in the West Ham a few times in late June....

 Great Northern Diver, West Ham
(Mark Bolton)

Saturday, 3 July 2010

Latest sightings

Friday 2nd July
Fantastic views of an otter again. One was spotted on the shore of the West Ham, just as it was entering the water. After playing in the water for just a wee while, it vanished. A few minutes later, it reappeared bounding back up the beach and then it lolloped across the grassy plain lying between the West and East Hams, then turned north and headed up the hill behind the bothy.

Pair of ravens were lingering around the island today, seen in the West Ham in the morning, and then later, chilling out at the top of the broch.

Thursday 1st July
Great Northern Diver in full breeding plumage in the West Ham.

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


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.