Scotland is home to a variety of black and white diving birds that live along the coastlines and offshore islands. These striking birds spend most of their lives at sea, only coming to land to breed and raise their chicks. Some of the most notable black and white diving birds found in Scotland include the puffin, razorbill, common guillemot, and black guillemot.
Puffin
The puffin is one of the most recognizable seabirds in Scotland with its large triangular bill and bold black and white plumage. It is a member of the auk family. Puffins measure about 30 cm long and have a wingspan of around 50 cm. They have black upper parts and white underparts. Their broad bills are brightly colored yellow, red, and blue during the breeding season. Puffins are excellent swimmers and can dive underwater to catch small fish, their main food source. They use their strong wings to “fly” through the water in pursuit of fish.
Some key facts about puffins in Scotland:
- Breeding populations are found along the north and west coasts of Scotland, as well as on offshore islands like the Isle of May in the Firth of Forth.
- They nest in crevices and burrows of coastal cliffs and grassy slopes.
- The largest puffin colony in Scotland is on the island of Lunga in the Treshnish Isles with an estimated 36,000 breeding pairs.
- They spend most of the year far out at sea, only returning to land to breed from April to August.
- Threats to puffins include pollution, overfishing, climate change, and predation by gulls and skuas.
Razorbill
The razorbill is another auk species found along the rocky shores of Scotland. Like puffins, they are black and white in color with a heavy black bill. Adults are about 38 cm long with a wingspan around 60 cm. Their plumage is black on the upperparts and white below. The thick black bill has a vertical white line running along the upper mandible. Their legs and feet are black. In breeding season, razorbills have a white line that extends from the eyes to the throat.
Here are some key facts about razorbills in Scotland:
- They breed in large colonies on remote rocky cliffs and islands.
- Major breeding sites include St Kilda, Sule Skerry, and North Rona.
- The total Scottish breeding population is estimated between 95,000 – 190,000 breeding pairs.
- Razorbills forage for fish, crustaceans, and other marine invertebrates by diving underwater.
- They can dive to depths of 120 m to find food.
- Chicks hatch in June-July and fledge at around 3-4 weeks.
- Threats include oil spills, fishing nets, declining fish stocks, and predation.
Common Guillemot
The common guillemot (also known as the common murre) is the most abundant diving bird along the rocky shores of Scotland. They are slender, dark-colored seabirds around 40 cm long with a wingspan of 60-70 cm. Their plumage is dark charcoal-brown on the head, back, and wings. The underparts are white. They have a long pointed bill. In winter, common guillemots have a white facial blaze that extends back from the eyes.
Here are some key facts about common guillemots in Scotland:
- They breed in densely packed colonies on narrow cliff ledges and rocky outcrops.
- Major breeding sites include Fowlsheugh, Cape Wrath, and the islands of St Kilda, Sule Skerry, Fair Isle, and Foula.
- Scotland holds around half of the world’s breeding common guillemots, estimated at over 1 million breeding pairs.
- They lay a single pear-shaped egg directly on bare rock.
- Chicks fledge at 15-30 days, jumping off cliffs and swimming away.
- Common guillemots feed on fish, crustaceans, mollusks, and other invertebrates.
- Threats include oil spills, commercial fishing, changes in prey fish, and climate change.
Black Guillemot
The black guillemot is the only guillemot species found along Scotland’s coasts that breeds on the mainland. Most other auks are restricted to remote cliffs and islands. Black guillemots reach about 30 cm long with a 50 cm wingspan. Adults in breeding plumage have slate-gray upperparts and wings contrasting with pure white underparts. Their bill is bright red with a black tip. In winter, their upperparts are dark blackish-brown. The bill becomes dark gray.
Here are some interesting facts about black guillemots in Scotland:
- They nest in crevices and caves along rocky shorelines.
- Breeding occurs all along Scotland’s coasts, including Orkney, Shetland, the Outer Hebrides, and the mainland.
- The total breeding population is estimated at around 4,500 pairs.
- Their diet consists of fish and benthic invertebrates.
- They breed from May-July with clutches of 1-3 eggs.
- Chicks fledge at around 4 weeks.
- Threats include oil pollution, habitat disturbance, commercial fishing, and introduced predators.
Migration and Wintering
Most of Scotland’s auks, including puffins, razorbills, guillemots, and black guillemots, migrate southwest in autumn to spend the winter far offshore in the North Atlantic Ocean. Their winter range extends south to Spain, Portugal, and even North Africa. Some birds may remain in northern coastal waters if food is adequate, but most migrate to more productive southern waters.
While away from the breeding colonies, these diving birds raft together in dense flocks on the sea surface. They continue to forage on fish and other marine life during the winter months. By late winter and early spring, they return north to the coastal cliffs and islands of Scotland in preparation for the breeding season.
Threats and Conservation
Scotland’s black and white diving birds face a number of threats both on land and at sea. On land, they are impacted by habitat disturbance, pollution, introduced predators, hunting, and excessive tourism activities near breeding colonies. At sea, they face threats from commercial fishing, oil spills, plastic waste, and declining fish stocks.
Climate change is another major threat facing auks and other seabirds. Rising ocean temperatures, acidification, and severe storms can negatively impact their prey sources. Several Scotland’s seabird populations have declined over recent decades, including important auk breeding sites like St Kilda.
Various conservation efforts are underway to monitor and protect Scotland’s seabirds:
- Monitoring and research of breeding populations
- Protection and management of key breeding colonies
- Control of predators like gulls, skuas, rats, and mink
- Regulations on marine pollution
- Sustainable management of commercial fisheries
- Public education and outreach
With substantial conservation efforts, Scotland’s cherished black and white diving birds can hopefully thrive for generations to come.
Conclusion
Scotland hosts globally significant breeding populations of colorful auk species like the puffin, razorbill, common guillemot, and black guillemot. These diving seabirds rely on the fish-filled waters around Scotland to sustain their populations. Careful management and conservation is needed to protect these iconic birds and their marine habitats into the future. Their unique black and white plumage and lively breeding colonies make them an integral part of Scotland’s coastal biodiversity and natural heritage.