Brünnich’s Guillemot | Life on the Cliffs of the High Arctic

From undertaking death-defying leaps as chicks to being one of the world’s finest divers, the Brünnich's guillemot is a fascinating bird of the world's northernmost seas. While they quite literally live their life on the edges, this vulnerable species is now being threatened by climate change and the rising temperatures in the Arctic.

The meaning behind the name 'Brünnich’s Guillemot'

Also known as: Thick-billed murre
Scientific name: Uria lomvia
Named after: Danish zoologist Morten Thrane Brünnich

The Brünnich's guillemot belongs to the auk family and is commonly found in Greenland, Iceland, and Newfoundland (46ºN-82ºN latitudes). Since the great auk went extinct in 1844, guillemots are now the largest auk family members.

Brünnich’s Guillemots nesting sites

Brünnich's guillemots breed on narrow cliff ledges with vertical faces overlooking the sea. Colonies are densely packed with several hundred thousand breeding pairs, often forming mixed colonies with black-legged kittiwakes or common guillemots.

Unique nesting behavior: Females lay eggs directly on narrow ledges without protective nests. The eggs have a conical or pear shape that causes them to roll in circles rather than off cliffs—though researchers debate whether this is due to egg shape or other factors like predators and weather.

Breeding and the death-defying leap

How to see Brünnich’s Guillemots in the wild

Habitat: Waters below 5°C (ice-free)

Population: ~850,000 breeding pairs in Svalbard

Brünnich’s guillemots spend their lives in waters which remain below 5°C, as long as it remains ice-free. The estimated number of breeding pairs in Svalbard is around 850,000. Some of the largest colonies are found around the Hinlopen Strait, the southeastern coast of Spitsbergen, and the islands of Bjørnøya and Hopen. Beyond that, small and medium-sized colonies are located in various spots on Svalbard.

Other important breeding colonies are in mainland Norway and the islands like Hjelmsøya and Hornøya. In Greenland, guillemot colonies are observed in the Upernavik district and Disko Bay area. Large colonies are found on Saunders Island in the Thule area. In Iceland, the cliffs of Látrabjarg that rise 400 metres from the sea are another spectacular bird colony.

One of the best ways to view the bird colonies is to take zodiac rides that provide close-ups of the narrow ledges where the young are hatched. Large flocks of foraging birds can also be seen from the decks of a cruise ship. There are options to hike to some bird cliffs in Svalbard, like the summit of Fuglefjella through the stunning valley of Bjørndalen. 

When to visit Brünnich’s Guillemot colonies

The best time to visit Brünnich’s Guillemot colonies is during the breeding season, from May and July. The chicks begin to appear by July and leave the nest in late July or early August. Obviously, weather and timing are important factors while photographing bird cliffs. For photographers, light conditions during the morning and the late afternoon hours are the best. Note that, zodiac rides may not be possible if the sea is choppy and visibility is poor.

Why life isn’t easy on the cliff for Brünnich’s Guillemots

While the bird cliffs are fascinating for observers, the guillemots live under constant threat from the marauding gulls flying above. Each time a guillemot heads to the sea for fishing, it runs the risk of its meal being snatched away by a gull while returning. Besides, there are other threats like arctic foxes, keeping the birds anxious and alert at all times.

Another threat is the effects of climate change on the food chain and the birds' physiology. Murres have a low ability to dissipate heat and are extremely sensitive to heat stress. This makes them vulnerable to the warming temperatures in the Arctic. Some reports have pointed out the death of some seabirds in their nests on hot sunny days.

In fact, every aspect of the life of these birds is tuned to match the survival requirements in Arctic conditions. But that rhythm is getting disturbed by the changing environment. For example, the rising levels of plastic waste in the ocean. 

Phytoplankton in the ocean give off an odorous compound, dimethyl sulfide (DMS). These chemical odours attract fish and squid, and foraging seabirds. Unfortunately, microbial layers on floating plastics can also produce DMS, distracting the birds from the food search.

In many ways, guillemot breeding colonies are indicators of marine ecosystem changes in the Arctic environment, including the status of the food chain. There are close ties between the success of a colony and environmental changes.

Brünnich’s Guillemots in climate and ecological research

The Brünnich’s guillemot is a key species, and it forms the largest seabird biomass in the Barents Sea. Since the mid-nineties, there has been a steady decrease in the breeding population of Brünnich’s guillemots in Svalbard, Norway, and large parts of Greenland. The average rate of decline is around 4% per year. 

While the exact causes behind the decline are not known, one reason is the impact of climate-driven changes on the winter food supply. This has resulted in the species being marked as vulnerable (VU) in Svalbard.

Scientists have tracked the levels of organic pollutants in Brünnich’s guillemot eggs to learn more about the status of the food chain. These have helped in monitoring the levels of PCBs or polychlorinated biphenyls, polyfluoroalkyl substances (PFASs), bromide and fluoride compounds, and mercury in the food chain.

For deeper investigations, teams of scientists tag these birds with miniature tracking devices that include a GPS, depth and temperature recorders. These help in determining their foraging patterns, how far they travel to collect food and dive depths. The results portray the impact of climate change on the species. The impact of marine pollution and marine renewable energy developments on the birds is also assessed.

Why these Arctic birds matter

Thick-billed murres play a crucial role in Arctic near-shore environments and food web stability. Their colonies reflect surrounding ecosystem health and inspire wonder among visitors.

These remarkable birds have evolved extraordinary strategies—from pear-shaped eggs that stay put on narrow ledges to chicks that remain motionless before their dramatic cliff leap. The leap may be assisted by parents, after which fathers assume primary care responsibilities at sea.

Understanding the Brünnich's guillemot life cycle helps us recognize the damage humans and climate change inflict on these vulnerable birds and motivates action to protect this fragile ecosystem.