The sand martin, like its more well known cousin the house martin, is a summer visitor to Britain to breed. It is a colonial breeding species and nests in tunnels it builds into soft, sandy banks. With its preferred nesting habitat sand and gravel extraction pits are popular with them especially after the mineral extraction process has finished. Here in Dorset in the Purbeck and adjacent areas we have many gravel pits and some of those are exhausted and abandoned but its seems there are very few sand martin colonies here. There are a few small colonies in Dorset but not a significant number and so most of the birds recorded here are passage migrants. In spring and autumn they can be seen in good numbers feeding over lakes and rivers prior to moving on to their breeding grounds elsewhere.
The sand martin is one of the first of the summer migrants to return with birds arriving here from about week 11 in mid March although a very small number are seen even earlier than that; indeed, in 2019 there were reports of sand martin in week 8 at the end of February. Once they start arriving reports come thick and fast until about week 18 at the beginning of May and then there are a small number of reports each week throughout the summer until picking up in week 29 in late July which is when the southern movement seems to start. There are far fewer reports of sand martins during the autumn exodus compared to the numbers passing through in spring. By week 36 in September they are all but gone but in 2017 there was single report in week 42 in October!
There are reports from forty sites in Dorset and many of these are of migrating birds; very few are breeding sites. The distribution map shows a definite tendency for reporting sites to be near the coast indicating observations mainly during migration periods.
An evening visit in April to Swineham Gravel Pit near Wareham or to Longham Lakes near Ferndown will almost certainly bring you views of sand martins and so add them to your Dorset list.
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