Little terns – A successful year?
The little tern, Sterna albifrons, is, as its name suggests, the smallest tern species to be found in the UK, with a length of around 23 cm and weight of approximately 50 g. The adult birds sport a yellow bill with black tip and orange/yellow legs in the summer and always have a patch of white on their forehead, which is portrayed by their latin name albifrons which derives from albus meaning white and frons meaning forehead.
Little terns nest around coastlines of the UK, which have shingle or sandy beaches. May is generally the start of the nesting period but chicks can hatch through to July. Usually two to three eggs are laid in a scrape the adults have made on the beach and incubation will last for around 2 ½ to 3 weeks. When born chicks are the picture of ‘cuteness’ but become mobile quickly and often take cover in neighbouring flora.
There is no mistaking this little bird when you hear its call, as it flies with purpose over the beach to its nest. There are around 1,900 breeding pairs in the UK but these birds are however amber listed due to the species European decline. So how has the little tern fared this year in the UK?
The species faces various threats at its breeding sites, including severe weather events, such as cold temperatures, strong winds and flooding; pressure from predation, whether from aerial predators, especially kestrels, or night time visits from foxes; varying ecological influences, such as prey abundance as well as disturbance from humans and dogs.
The EU LIFE+ Nature Little Tern Recovery Project is a five year scheme to help protect this species and its future survival. This project aims to help increase breeding success by preventing disturbance, in many cases aided by the establishment of an electric fence helping to keep out four legged predators, whether foxes or dogs, and preventing trampling by people; carrying out appropriate site management; helping to increase public awareness as well as contributing to national schemes through projects such as colour ringing, which will help to collect more information regarding bird movement and demographics.
This year had varied fortunes for colonies across the UK and according to the BTO the breeding numbers for 2015 were actually 15% less than 2014. Last year was however a particularly successful year in many areas, such as at Chesil Beach, Dorset (the only colony of little terns in the south west), with 33 pairs raising 60 chicks. This year however saw a drop in young raised, only 34. Hang on a minute – ‘only’! Considering in 2009 no pairs were present, 2015 is still a huge success for this area. Further amazing news came from this site this year during colour ringing of adult terns for the EU project, when it was found that one ringed bird was sixteen and another fifteen years old. Thanks to these birds being previously ringed, it was possible to calculate their age, which produced this astonishing result, meaning each bird has migrated over 100,000 km in its lifetime.
Other areas have also had unexpected events this year. According to the RSPB around 30% of the national little tern population go to the east coast to breed, with Norfolk being an especially important area. Winterton-on-Sea was famed for a huge colony of birds, around 300 pairs were recorded in 2014, but this year the terns abandoned the site, with a lack of food being partly to blame, despite 60 nests having been set up. These birds are however very resilient and many moved along the coastline to breed at Eccles, thankfully fledging 90 chicks from 78 pairs. It was unknown why a lack of food was occurring, although it was reported that in July sandeels and herring fry were readily available. Bad weather and predation pressure may have also played a part here. Another previously productive site, Kessingland in Suffolk, was also abandoned this year.
Other sites had largely positive news with record numbers of chicks raised at Benacre in Suffolk and Kilcoole, Ireland. At Benacre 180 chicks fledged from 116 pairs, the greatest number of fledglings from a Suffolk nesting site for more than fifteen years. The colony at Kilcoole saw around 289 chicks from 155 pairs, this being the best year since the start of the project for fledglings.
Thanks to schemes involving various organisations and hours of dedicated work by little tern wardens and volunteers, recording bird behaviour, hysterically chasing off aerial predators (with what appears to be some strange kind of dance), intercepting overexcited dogs before they reach the colony; inspiring and educating the public about this fantastic little bird or frantically deterring foxes in the darkness, these little birds have survived another breeding season.
Once the breeding season had finished, during July and August, the birds departed from their breeding grounds in the UK and made their way to their wintering grounds in Africa. Their southward migration took many across European and African coastlines before they reached West Africa, although some may have continued further south. But one thing is for sure, and that is that they will be back next year and dedicated wardens and volunteers will be there to watch over them.
2,826 total views, 3 views today
Latest posts by A Johnson (see all)
- Why Attenborough Documentaries will always be needed - 12th December 2016
- More than one non-native crayfish species in the UK - 25th November 2016
- The Science of Autumn Leaves - 7th November 2016