Skylarks can be heard singing around the reserve, so this week we are profiling this small, brown bird with a big voice. Skylarks (Latin name: Alauda arvensis) are larger than sparrows but smaller than starlings. They measure between 18 and 19 cm in length, weigh between 33 and 45g and have a wingspan of 30 to 36 cm. They have streaky brown bodies and wings, white sides on their tails and a small crest on their heads which they can raise when they are excited or frightened.
Skylarks are found throughout the UK in open countryside, both lowland and upland. Although they can be hard to spot on the ground due to their well camouflaged colouring, male Skylarks are easy to spot when in their distinctive song flight, rising vertically up in the air with rapid wing beats, then hovering in mid-air for several minutes while singing, before plunging back down. Song flights of up to an hour long have been recorded and Skylarks can reach 1,000 feet (approximately 300 m) before they descend. They also sing from perches such as large rocks or fence posts.
Skylarks nest on the ground, ideally in vegetation between 20 and 50 cm tall, making a hollow lined with leaves, grass and animal hair. They usually make two or three attempts at nesting during the breeding season. Females lay between two and six, greyish-white, spotted eggs, which they incubate for 11 days. The males and females then feed the chicks together, starting with insects for the first week and progressing to seeds and shoots as well after that.
Numbers of Skylarks have decreased in almost all countries in northern and western Europe. In the UK, the Skylark population halved in the 1990s and it is still declining, so the species is now classified as Red under Birds of Conservation Concern. Skylarks need to produce at least two broods of chicks a year to maintain population levels, but, if crops or vegetation are too tall and dense, they are not able to do this. Sowing of cereals on farmland in autumn has adversely affected the Skylark population, as this means that the crops are too tall for the birds to raise more than one early brood. If crops are sown in spring, this allows Skylarks to make further nesting attempts later in the year, but there has been a widespread switch from spring to autumn-sown cereals. Skylark nests may also be destroyed by mowing in grass fields and, on land where there is increased livestock, the grass is too short for Skylarks to build their nests and they are at risk of being trampled.
Research carried out into Skylarks and their habitats have found that small areas left unsown in winter cereals boost nesting opportunities and availability of food for Skylarks, making them more likely to nest and reproduce successfully. At Hope Farm, a 180-hectare farm in Cambridgeshire, the RSPB investigated how to use wildlife-friendly farming methods to benefit species such as Skylarks and the organisation manages all of its reserves to improve habitats for birds, while working with farmers to advise on ways to support bird populations.
The song of the Skylark has been the subject of works of literature and music, including those by Geoffrey Chaucer, Percy Bysshe Shelley and Vaughan Williams. Listen out for its beautiful song and keep your eyes peeled while exploring the reserve and surrounding countryside – you might be lucky enough to witness its song flight yourself.