May24

Spectacular Seabirds

Categories // Hebrides Wildlife Officer

Spectacular Seabirds

Marine mammal sightings are warming up on CalMac ferries as the season moves on!

There have been sightings of minke whales, bottlenose dolphins, and common dolphins across the network. Including a group of over 40 playful dolphins exciting passengers on the Oban-Castlebay route recently, with similar numbers seen on the Coll and Tiree sailings. 

But even on quiet marine mammal days there is always some wildlife to enjoy thanks to the fascinating and spectacular seabirds that we are so lucky to have around the British Isles. During spring and summer months the number of birds around our coasts swell as they arrive, literally from across the oceans, to breed on our islands and rocky coasts. It has been claimed that during the breeding season 70,000 tons of seabirds can be found on the wing around British coasts. The West Coast of Scotland certainly plays a major role in this abundance with internationally important breeding sites across the region from Ailsa Craig in the south to the Shiant Islands in the Minch, and St Kilda off the far west of the Outer Hebrides. Seabirds travel vast distances to forage and can be seen on all the CalMac ferry crossings. 

The CalMac Marine Awareness Program recognises the huge diversity of habitat and marine life that the region is famous for and, as well as the monthly ORCA marine mammal surveys that I lead, Joint Nature Conservancy Council (JNCC) are developing a new citizen science seabird survey programme to be used on the ferries. I will be taking part in these surveys as a mentor on the survey teams and last week we spent time on the MV Finlaggan trialling the scheme between Kennacraig and Islay. I believe that the week was deemed a success by those from JNCC who are developing the programme and it is worth keeping an eye on its progress through the CalMac Marine Awareness Programme and JNCC pages as well as those of MARINElife who will be helping to coordinate the survey programme. If you have an interest in seabirds and would like to volunteer to take part in the surveys, it is certainly worth making contact.

If you are out on the ferries over the next few months do take the opportunity to check out some of these birds. Not only are they beautiful but they are extremely well adapted to living in what is essentially an extreme environment. 

Everyone loves a colourful puffin and it is possible to visit colonies on Lunga in the Treshnish Isles, Canna in the Small Isles, or the Shiant Islands in the Minch.  Yet the majority of their time is actually spent at sea during the breeding season as they fish for sandeels with each individual needing more than 400 per day to feed itself and it’s cutely named, “puffling” chick.  As a result you can encounter them from the outside decks of CalMac ferries, particularly around the Small Isles of Eigg, Muck, Rum and Canna, and also on the crossings from Uig on Skye to Lewis and Harris. Like their auk cousins the, guillemots and razorbills, their prowess in the air is debateable but where they really excel is under the water. Phenomenally well adapted to underwater swimming they dive from the surface, propelled by their wings, sometimes as deep as 200 metres, to hunt. Guillemots have even been recorded at depths of 500 metres which is actually pilot whale territory!  Make the most of the puffins in the breeding months as during the winter they individually disperse out into the Atlantic and lose their quintessential colourful breeding bill. 

Perhaps the complete opposite of the puffins, and one of my favourites, are the Manx shearwaters. Despite lacking the impressive colours of the puffins, with simple two-tone black and white plumage, these relatively small birds are not to be underestimated.  Pretty poor underwater (only diving to a maximum of 3 metres, in comparison to the puffin) and heavily disabled on land, their true medium is in the air, just above the crests where they excel.  Shearing and soaring over the ocean, harnessing the energy just above the waves, the wing tip will sometimes clip the surface and a puff of sparkling water can be seen under the right light conditions. 

The combination of rapid wing beats followed by stiff winged soaring will take them all the way back to the coasts of South America at the end of the summer where they overwinter and feed.  This remarkable migration can be made in a little over a fortnight by these plucky birds. 100,000 pairs of manx shearwaters return to the Hebrides each year to breed on the Isle of Rum. Their only real similarity to puffins (apart from their latin name: Puffinus puffinus) is their inclination to nest below ground in burrows giving them protection from predating birds such as great black-backed gulls and skuas. 

Good CalMac routes to see them from are Oban-Coll/Tiree, Oban-Castlebay, and around Rum and the Small Isles. Indeed, one of the great wildlife spectacles of the Hebrides, is cruising towards Rum on MV Loch Nevis on a calm summers evening surrounded by tens of thousands of shearwaters settling and rafting on the water as they wait for the cover of nightfall to return to their burrows and waiting chicks.

Another stalwart of ferry travel here is the ever present Northern gannet. St Kilda is the most impressive gannetry in the region and is the second largest colony in the world with over 60,000 pairs nesting there. Although heavily persecuted in the past, gannets’ generalised diet and the ability of their 2 metre wingspan to allow them to forage for huge distances has led to a rising population in recent decades; almost a unique trend in current seabird populations.  We see them all around the network and at times they grace us with their presence right above the ferry as they ride the up draught, giving magnificent views of their size and their stunning head and bill markings. 

For me, the most exciting moment is when I see them dive feeding. This is a phenomenal activity in its own right. They tuck their wings behind them and plunge dart-like into the ocean from great height, often reaching depths of up to 20 meters as they hunt their prey. It has been calculated that they can hit the water at up to 60mph and would seriously injure themselves without the physiological protection of cushioning air pockets under the skin, a membrane to cover the eyes before impact, and nostrils enclosed internally within their beaks. The added bonus for me is that they are regarded as “the whale watcher’s friend”. We use diving gannets to help us find whales and dolphins. Any group of seabirds feeding on the ocean indicates the presence of food and therefore the possibility of marine mammals but groups of feeing gannets can be seen a long, long way away.  Train your binoculars on the water under them and you may well find that a minke whale or a group of dolphins is herding the fish from below and pushing them to the surface where they are picked off by the gannets.

There are too many magnificent seabirds out there to mention them all here. But others such as eider ducks, black guillemots, great northern divers, fulmars, and Arctic tern all make the grade, as do the various gull species. They all have fascinating specific adaptations that allow them to survive in a hostile environment and they can all be seen from our coasts, islands and ferries, particularly over the next few months.