Seven facts you didn't know about little terns

1. They weigh the same as a tennis ball

Little terns are a rare and declining species. These dainty seabirds are under 25cm in length and weigh about the same as a tennis ball. 

2. Despite this, they rack up the air-miles

They spend the winter in West Africa and migrate to Britain to breed, with several pairs nesting on National Trust-owned coastline in Northumberland and Norfolk. In early 2015, a little tern ringed by the RSPB on the National Trust’s Blakeney National Nature Reserve the year before, was seen on its wintering grounds in The Gambia, West Africa – nearly 5,000km away.

3. They can live to a ripe old age

In 2014, a little tern was found to have died at Blakeney, having been ringed as a chick in Lincolnshire 21 years previously. The bird, a female, had an egg inside, so was clearly still breeding at 21, having migrated between England and Africa 19 times during her life. This was the oldest little tern ring recovery, until the Farne Islands found one 21 years and 10 months old soon afterwards!

4. There are fewer of them 

Sadly, the British breeding population is now thought to be less than 2,000 pairs, having declined by 25% since the 1980s. Little terns face many pressures. They like beaches with sand and fine shingle, which are often popular with people and dogs, which can accidentally disturb the birds as they are highly sensitive to disturbance.

5. They don't lay their eggs in sensible places

They tend to lay one to three camouflaged eggs on the beach, often close to the high water mark. This means that nests regularly get washed away if big tides are combined with stormy weather. Strong onshore winds in June regularly cause problems for little terns nesting in Norfolk. The fact they lay their eggs on the ground also makes them vulnerable to predators of which the list is very long: from every species of gull to most birds of prey, as well as many small and large mammals, crows, snakes and even herons.

6. They are picky eaters

Food availability is also crucial to their success. They will only fly a short distance from their nest site to forage. They feed mostly on Sand Eels and young Herring, by plunge-diving to catch them, and will also feed on shrimps and small invertebrates. The number of eggs they lay and the survival of their chicks is largely dependent on food availability. The Norfolk name for the little tern is ‘Little Pickie’, because the way they skillfully ‘pick’ fish from the sea with their bills. This is also the name of the rangers’ boat at Blakeney.

7. Decoy tactics are working

The National Trust are partners in an RSPB-led EU LIFE+ Project, which aims to help little tern recovery in Britain. As part of this project, at Blakeney, National Trust rangers have made little tern decoys and played recordings of their calls, attracting birds to nest in areas less vulnerable to flooding. In 2014, 60 little terns nests were all flooded, but in 2015, 11 pairs successfully nested in a more suitable area of beach thanks to the use of decoys, all going on to fledge young.

In partnership with other conservation organisations, and with the help of our supporters, we are engaging people’s love of nature and the outdoors, and trying to make the countryside healthy and rich in wildlife and culture. We are keeping our fingers crossed for the little terns this summer.