In early summer woods which will later be full of fungi are home to one of our most mysterious and least-seen breeding birds…
As dusk tightens across Britain’s heaths and woodland edges, sharp-eyed walkers might spot a strange hawk-like bird flitting just above the trees. Its pointed wings and long tail are those of a kestrel or cuckoo, but its bouyant flight with rapid direction changes and sudden swoops and rises are more like those of a martin chasing invisible moths.
More noticeable than the blurred silhouette in the gathering gloom is the strange ‘churring’ sound, rising and falling in a monotonous purr as the bird sweeps back and forth. Dusk is almost the only time to see these strange creatures which spend 22 hours a day sitting on the ground or perched among the forestry brash where their cryptic, grey-brown, mottled plumage provides ideal camouflage.
This and their silent flight has given them an almost supernatural reputation. Indeed, as one of their numerous local names, ‘goatsucker’, suggests, they have even been credited with suckling milk from goats. Although nightjars may turn up almost anywhere, they are most common in southern England – notably in the heaths of Dorset and Surrey, with good populations in the mosaic of commons and scrub found in the New and Thetford Forests. In much of Wales, northern England and southern Scotland, however, they are more likely to be found in recently felled and replanted conifer woods.
Unfortunately the birds have experienced a cataclysmic drop in numbers over the past century. In 1900 they were found everywhere except the far north of Scotland, but numbers crashed mid-century, reducing breeding pairs to less than two thousand by 1981. Fortunately this had risen to just over 3,000 by the time of the next count, but still only a fraction of its original population.
The fall is probably mainly due to habitat loss for nightjars have very specific nesting requirements, needing bare earth, yet reasonable cover. Until recently this usually meant lowland heaths, commons and moors, but unfortunately Britain has lost some 80% of these to development over the past century. Fortunately it now it appears woods which have been clear-felled and replanted provide an ideal habitat that mimicks the traditional heathland breeding site, thanks to the mosaic of discarded brash, undergrowth and young saplings. This provides the ideal camouflage for their nests which are built on the ground with the minimum of adornment, the birds relying almost entirely on their superb camouflage to hide the eggs and young from predators.
Nightjars are generally solitary creatures, but have a complex breeding cycle. When the males return from the winter quarters in sub-Saharan Africa, they establish territories in suitable habitat, declaring their ownership with a loud, churring calls during their dawn and dusk patrols. This attracts a female who lays a clutch of two eggs in a scrape in the ground. The male remains in help feed the young, but after a fortnight the female leaves them to the sole care of the father and begins afresh. Sometimes she remains loyal to her partner, but frequently finds a new mate. Surprisingly, it is at this stage that the original male can find help arriving from an unusual direction. It is quite common for a second male to chip in as ‘uncle’, helping to feed the now almost fully-grown young, even though he has no genetic stake in the clutch.
This article is reproduced by kind permission of Daniel Butler www.fungiforays.co.uk