In this month’s marine life column, Aron Sapsford, ornithological warden on the Calf of Man, discusses the seabirds that can be seen in Manx waters.

When we talk about marine life we often tend to think about whales and dolphins or sea creatures such as crabs and molluscs, however there are an array of bird species that specialise in living their lives near to and at sea.

The Isle of Man is host to 16 species of true seabirds that breed annually around our coastline, plus several other seabirds that may occasionally breed, as well as sea ducks, waders and even some passerines - perching birds, like sparrows but also includes some larger birds like ravens - that utilise maritime habitats as either feeding, breeding, nursery areas, migration stop-over or wintering locations.

The most iconic of our seabirds is the Manx shearwater, historically referred to as ‘Manks Puffins’ it is likely that the population on the Calf of Man was, in its heyday, one of the largest, with 95% of the world population known to be breeding in the Irish Sea.

Infestation of the Calf by brown rats - or longtails - caused the shearwater population to be wiped out in the 17th century. However, the sea area to the south and west of the Isle of Man remained crucial for the species, with GPS tracking of breeding birds from the Welsh islands of Bardsey and Skomer showing that the territorial waters surrounding the Isle of Man provide important foraging opportunities for the species.

Subsequently a collaborative project, led by Manx National Heritage, to rid the Calf of longtails was begun in 2012 and recovery of the shearwater population has responded with an estimated 1,000 pairs in 2022.

The Atlantic puffin is another species that is likely to have benefitted from the eradication of longtails and a Manx Wildlife Trust-led project to attract birds to return to the Calf, using decoys and a sound lure, has seen encouraging signs of birds present around their traditional breeding haunts in recent summers.

Small populations of puffin also breed at the nearby Spanish Head, as well as Peel Hill and Maughold Head.

Unfortunately, it’s not all good news and many of our seabird populations are in serious decline.

Annual monitoring by the Calf of Man Bird Observatory and through a programme of colony surveys undertaken around the main island coastline by DEFA, Manx Birdlife and the Manx Ornithological Society show that most seabird species are decreasing in numbers.

Arctic and little terns breeding along the Ayres coast suffer from disturbance by humans as well as predation by both avian and ground predators, including rats, hedgehogs and cats. European shag, along with common guillemot, razorbill and kittiwake show declining population trends and contraction in breeding sites linked to the availability of food sources and repeated disturbance of foraging areas by marine traffic.

The Isle of Man is also host to five breeding gull species, with small populations of black-headed gull and common gull in the north of the island.

Around much of the coastline you can find herring gulls and great black-backed gulls and, in smaller numbers, the lesser black-backed gull. In recent decades some of these birds have begun to nest in towns and cities, bringing them into regular conflict with humans.

The British Isles holds a significant percentage of the world populations of these gulls which are listed as of conservation concern (Birds of Conservation Concern in the Isle of Man 2021 - Manx BirdLife) due to population declines since the 1970s.

With our seabirds under threat, it’s increasingly important to better understand our local species and their requirements, and that often starts with knowing how many and where.

Various organisations in the island - Manx Birdlife, MNH, MWT and DEFA - cooperate to undertake surveys and maintain important research carried out on the Calf of Man Bird Observatory, but everyone can contribute to improving the status of our sea and coastal Manx birds:

• Consider the disturbance of feeding and roosting birds when walking or exercising your dog along the beach

• Keep cats indoors/in your garden during the breeding season, especially at night

• Avoid disturbance of ground-nesting birds, especially high up on the beach (above the tide line)

• Avoid disturbance of breeding or resting sea birds when using power boats and jet skis at sea

• Avoid littering, or picking it up; especially nylon fishing lines or entangling plastics

• Report sightings to http://manxbirdlife.im/sightings/

•Join a bird group to learn more.