Common House Martin or Western House Martin (Delichon urbicum) has a wingspan of 26-29 cm and can live up to five years. 

What do they look like?

The house martin has a blue-black back, a blue-black cap, a white throat, and a white underside.

Where and when can people find them on Alderney

There are only 2–6 breeding pairs of House Martins on Alderney, according to the Alderney Bird List updated in October 2025 by Alderney Bird Observatory. More birds can be seen in spring and autumn as migrants passing through. House Martins are often recorded on Alderney in April and May. In autumn, several hundred birds may be seen feeding on insects near the cliff areas which are sheltered from the wind.

On Alderney, you can spot House Martins flitting over Platte Saline Pond, Longis Pond, around Houmet Herbet, or near the south cliffs. They are often seen with sand martins and swifts. You can learn to tell these birds apart with this article.

House Martins nest on cliffs. In many parts of southern Europe, they still breed in remote locations, such as high mountain cliffs.

As their name suggests, House Martins are also associated with buildings, where they nest under the eaves of houses. This has become much rarer on Alderney.

What do they eat?

House martins catch flying insects and drifting spiders and eat them on the wing. 

Why is house martin on the Alderney’s key species list?

The House Martin is on the Red List of Birds of Conservation Concern 5, which reviews the status of all regularly occurring birds (breeding or overwintering) in the UK, Channel Islands, and Isle of Man. The species was moved from the Green List to the Amber List in 2002, and from the Amber List to the Red List in 2021, indicating an increasing level of conservation concern.

The population of House Martin in the UK decreased significantly from 1994 to 2024. 

Graph credit: Population trend of House Martin in the UK from 1994 to 2024, BTO/JNCC/RSPB Breeding Bird Survey.

Over 27 years, between 1995 and 2023, the UK population decreased by 42%, according to the Breeding Bird Survey 2024 (p. 19).

House Martins visit Alderney and the UK in spring and summer and migrate to Africa during the winter months. It is still unclear exactly where they stay in Africa. However, due to their wide migratory range, many factors can affect their population, including issues on wintering grounds and stopover sites, declining food availability, limited nesting sites, and reduced availability of mud for nest building due to changes in the weather.

House Martins prefer to nest on older buildings, particularly those with wide eaves, gables, and soffits made from natural materials, which allow their mud nests to adhere securely. However, many older buildings have been converted or redeveloped, while newer buildings often lack eaves or have very shallow ones. Some also use modern, plastic materials that make it difficult for mud nests to stick. All of these factors contribute to a shortage of suitable nesting sites.

Additionally, changes in weather patterns affect migration timing, the availability of mud for nest building, and the abundance of insects and spiders, which are their main food sources.

How you can help

You can:

• Create a wildlife-friendly garden or build a pond to encourage more insects. This provides an important food source for House Martins and other wildlife.
• Encourage House Martins to nest on your home by installing artificial nest cups (for more information, please read this flyer by The House Martin Conservation).