Management and creation of sand martin nest sites
Sand martins usually nest in natural sheer cliff faces on river bends or in man-made sites such as gravel or sand pits. They use vertical earth and sand banks soft enough for burrowing, in open areas.
About sand martin nest sites
Sites are abandoned once the face slumps, becomes weathered (forming a resistant crust), overgrown with vegetation, or accessible to predators such as weasels.
Management of existing nest sites may be needed to retain their value for sand martins. Natural erosion of the cliff base may be sufficient to maintain a steep and vegetation-free face.
Where natural erosion is insufficient, vegetation should be cleared from the cliff face over the winter, to ensure that the birds' flight path is clear. Recutting in the winter of a new sheer face of at least 2m high over water may be necessary where erosion is not occurring.
Build your own colony
Safe and long-lasting banks can be created for sand martins.
When creating a bank the face must be vertical and rise at least 1.5m above normal water level. It should be as long as possible, ideally over 5m. Wooden stakes, boulders or gabions may be used to protect the toe of the cliff but, if erosion is prevented, the bank may become unsuitable.
If banks are less than 1.5m above water, or the substrate is stony or liable to slumping, then stoneless spoil can be brought in and packed behind shuttering (available from builders merchants), finished with turf or reseeded, trees or shrubs planted, and the area stock-fenced if necessary. It should be left at least a year to settle, and the shuttering removed in early May before the birds start prospecting for a nest site.
Banks have been made for sand martins using a weak or dry concrete mix around clay or polythene pipes. If this option is chosen, the bank must be vertical with water at its foot.
Pipes should be of at least 6cm internal diameter set in rows 30cm apart with the pipes at 20cm spacing, and the bottom row at least 1m above summer water level. The pipes should be no more than 1m long, sloping very slightly up into the bank (to prevent rainwater flooding the nest chamber) with the opening flush to the cliff face.
It is best to fill the pipes with sand for the birds to excavate, with the entrance hole half blocked with cement. The birds should be able to tunnel farther into loose sandy material at the other end of the pipe. It is essential that the pipes are dry inside, not acting as drains. Ideally, pipes should be scraped out and refilled each winter.
To carry out any of the works described above will require the permission of the landowner.
In some circumstances additional permission may be needed from specific public bodies, for example:
- Construction of a large artificial nesting bank raised above the land surface where there was no existing bank (consult local planning authority)
- Cutting a new face to a river or drainage channel bank or constructing a steep cliff by in-filling against a sloping river or drainage channel bank (consult drainage or river management body)
- Works within a Site of Special Scientific Interest (Great Britain) or Area of Special Scientific Interest (Northern Ireland) will need the consent of the relevant statutory nature conservation body: English Nature, Countryside Council for Wales, Scottish Natural Heritage, the Environment and Heritage Service (Northern Ireland).
- The need for permission is often dictated by local circumstances. The best course of action is to contact the relevant organisation to discuss proposals at the earliest possible stage, before any commitments have been made.