Posted 4th Jul 2014
Surveillance of a usually sociable species has uncovered astonishingly robust behaviour when a sand martin gatecrashed the nest of a breeding pair and their young, outstayed its welcome and was duly evicted
The interaction, captured on film, shows the intruding adult seeking refuge in the breeding pair’s nesting chamber. The apparently unwell bird is temporarily tolerated, even settling underneath the 10-day-old chicks. The clips (click here to watch) show the sand martin arriving in the nest sometime before 8am on Friday 30th May. It remained there for a few hours before being dragged out by one of the parents.
The footage was filmed in Leicestershire & Rutland Wildlife Trust’s artificial sand martin nesting bank at Rutland Water – Britain’s largest reservoir and smallest county. The bank, constructed in 1999, now has approximately 200 breeding pairs each year. In a good year, around 1,000 chicks will fledge from the bank.
Tim Mackrill, Senior Reserve Officer at Leicestershire and Rutland Wildlife Trust’s Rutland Water Nature Reserve, said: “Although sand martins are sociable and gregarious birds that nest close together in summer and roost together in the autumn, this footage shows how vigorously adults will defend their nesting site. It’s fascinating to see and gives us a rare insight into interactions between adults in this important colony.”
Sand martins are an internationally important species with at least 20% of the European population in the UK. They visit between March and October, travelling around 3,000 miles from sub-Saharan Africa to the UK. Despite their small size, similar to a robin or smaller – sand martins regularly fly large distances. Unlike most birds, sand martins migrate during the day to allow them to feed on airborne insects whilst on the wing. While this species is not considered to be at risk of extinction, there are worries about the status of European populations as, when droughts occur in the bird’s African wintering grounds, insects decline and sand martin populations struggle.
The smallest member of the European hirundines, sand martins are grey-brown above and white below, with a narrow grey-brown band across the breast separating their white throat from their white belly. While it’s not always easy to distinguish in flight, it is much easier to identify their call. Repeated continuously during flight, it is a dry rasp often compared to the noise of coarse sandpaper, ‘trrsh’, which quietens when the individuals settle into a roost.
Facts about Sand Martins (Riparia riparia):
- A migratory bird and one of the first true summer migrants to arrive back in the UK each spring
- They over-winter in the Sahel, a region of Africa south of the Sahara desert
- Sand martins migrate during the day so they can feed while they fly
- Adults weigh little more than a £2 coin
- They nest in sandy banks on rivers, cliff faces or at manmade sandbanks
- Sand martins excavate a nesting tunnel with their sharp claws and small beaks
- The nesting tunnels can be up to one metre long with a nesting chamber at the end
- The birds lay four to six white eggs on collected straw and feathers in a chamber at the end of the burrow. The eggs take 14 days to hatch
- Chicks fledge after 19-24 days, although they rely on their parents for food for another two weeks
Seven sand martin spots to experience this summer:
Attenborough Nature Centre, Nottinghamshire Wildlife Trust
Nottinghamshire Wildlife Trust’s sand martin hide and artificial nesting bank was built in the winter of 2013-14, funded by the Heritage Lottery Fund. It provides nesting opportunities for up to 150 sand martins each summer. The integrated ‘sunken’ bird hide has panoramic views across Coneries Pond and enables visitors to watch the sand martins at close quarters as they feed over the water and return to their nests. As the nests become established, Nottinghamshire Wildlife Trust will use small cameras within the nesting chambers to record the nesting behaviour. A BTO nest record check on the evening of Friday 30th May 2014 revealed 34 active nests. Nine of the nests currently have eggs (numbering between one and three eggs in each) and one of these nests seems to have birds incubating now. Find out more about Attenborough Nature Centre.
Rutland Water, Leicestershire & Rutland Wildlife Trust
An artificial breeding cliff designed specifically for sand martins was built at Britain’s largest reservoir, in its smallest county, in the spring of 1999. 347 sand-filled clay pipes for breeding burrows sit in two banks of holes, with a covered walkway between them to allow observation and bird ringing. In 2013, Leics & Rutland Wildlife Trust built a second artificial bank here which has over 500 nesting chambers. Find out more about Rutland Water.
Brockholes, Lancashire Wildlife Trust
Sand Martins nest in a purpose-built wall, created by the Lancashire Wildlife Trust's Contracts team. It contains 68 nesting holes drilled in at random to imitate the birds' natural nesting habits as closely as possible. The holes are 40mm wide – the perfect dimensions for sand martins, and each nesting hole is surrounded by roof insulation so the martin chicks can stay warm and dry. Find out more about Brockholes.
Summer Leys nature reserve, The Wildlife Trust for Beds, Cambs & Northants
At Northamptonshire's Summer Leys reserve an old loading dock provides sand martins with a high rise ‘des-res’. This wetland, within the Upper Nene Valley, is made up of flooded gravel pits, flood meadows, species-rich neutral grassland and mature hedges. Each year, Sand Martins have nested in the drainage holes in the old quarry conveyor loading ramp, located on the path along the disused railway, owned by Hanson UK and forms part of the Summer Leys perimeter walk. Numbers breeding here have ranged from one to five pairs. At the end of March 2014, 50 new holes were drilled in the ramp wall to provide additional nesting opportunities for returning birds. Temporary fencing is currently guiding walkers around the northern side of the ramp to minimise disturbance at the new colony, but it is planned to erect permanent gates and fencing across the disused railway line to protect the nesting birds during future breeding seasons. Find out more about Summer Leys.
Montrose Basin, Scottish Wildlife Trust
Sand Martins can be seen here usually between April and August. They can be seen very easily from the Visitor Centre thanks to the ‘Sand Martin Wall’ where the birds nest most years. Find out more about Montrose Basin.
Wood Lane nature reserve, Shropshire Wildlife Trust
Shropshire’s biggest sand martin colony is at Wood Lane nature reserve, near Ellesmere. However, the birds don’t nest on the nature reserve, but next door in the working quarry. Some 500 pairs nest in a huge mountain excavated sand. This enormous heap, which is their favoured spot, lies within the working part of the quarry and can clearly be seen from the nature reserve, created as part of the restoration process. The birds fly back and forth, feeding over the lagoons, where insects are plentiful. Find out more about Wood Lane.
Portrack Marsh, Tees Valley Wildlife Trust
The best place to see sand martins is to visit Portrack Marsh near Stockton, at the side of the River Tees. The birds nest on the sandy cliffs overlooking the Tees and Portrack Marsh is used as a feeding site. Another reserve to see them is Coatham Marsh, Redcar. You’ll see sand martins feeding over the wetlands but none have yet decided to move into the new bank as it was only finished in May. Find out more about Portrack Marsh.
Images courtesy of The Wildlife Trusts: Shropshire Wildlife Trust, Rutland Water