We are privileged to be able to share this piece from Tim Kohler at Natural England, in which he discusses nightjars at Humberhead Peatlands National Nature Reserve. After a devastating and ongoing wildfire beginning in May this year, Tim considers how the nightjar might be impacted by the changes wrought on the landscape, and looks to the future of the site.
The Nightjar – After the Fire
Nightjars (more specifically the European Nightjar, Caprimulgus europaeus) are a medium sized bird, about the same size as a small dove. They are a greyish-brown colour, streaked with black, in a broken speckled pattern, the males having distinctive white spots towards the end of the wings and tail which they show off in mating display flights with wing-claps.
Nightjars are migratory birds, spending the winter in the southern Sahara, and then flying up to Europe, usually at night, in May to nest and breed here, before heading back off to Africa in September. Recent research on the moor has shown that they can be very site faithful, with one ringed female found to be nesting within 50 meters of her previous nest from the year before. Other birds will roam more widely, and seem to be quite happy to nest on different sites each year. They nest on the ground, hardly making any nest at all, just a little scrape amongst low heather or emerging bracken, usually laying 2 eggs. In good years they may manage 2 broods. Their colouring blends in perfectly with the ground and they are almost impossible to spot on the nest, or when they are roosting. Despite this, we think that the main cause of nesting failures is predation, with eggs and chicks being taken by foxes, stoats, weasels and crows. They are also vulnerable to disturbance from people and particularly dogs, so we would urge people visiting the site in the breeding season to keep their dogs under close control, or ideally on a lead.
They have a very distinctive call, which is a long continuous “churr”, or rolled R sound, which may last for several minutes without pause. It is the male who makes this call, and they use it to advertise their territory, actively chasing off other male intruders. They are best heard early in the season (June–July).
They feed on insects, mainly larger moths and beetles, and their unique feature is that they feed at dawn and dusk, with some activity through the night. They have huge eyes, and a very wide mouth, with a rim of bristles, and catch their prey on the wing, often hawking along the edges of scrub and woodland. They will often perch on a branch, or on the ground and look up, waiting for their prey to be silhouetted against the lighter sky. They can also be seen hunting around artificial lights. Their normal habitat is heathland, or heathery ground, with small trees and scrubby vegetation. Recent research on the Humberhead Peatlands National Nature Reserve (NNR) has shown that they are quite variable in the area and distance they will travel to feed. Some birds in good habitat stay close to the nest, but other birds will travel several kilometres to feed in favoured areas.
Possibly due to their nocturnal habits, they have attracted some curious folklore, and a number of curious names. Sometimes called a Gabble-ratchet, although this name is also attached to other night-flying birds, they are also known as Goat Suckers due to the belief that they would suck milk from goats.
The Humberhead Peatlands NNR (Thorne, Hatfield, and Crowle Moors) is a perfect haven for them, with extensive areas of heather and scrub, and the natural vegetation provides an abundance of the moths and beetles they prefer. It is a little ironic that it is only because the moors have been dried out by previous drainage and peat cutting that the site is so good for them, and recent restoration work has sought to balance the recreation of wetter habitats with management of drier areas to suit nightjar. While there are other good populations in North Lincs., Sherwood Forest and the North York Moors, Humberhead NNR holds about 1.5-2% of the total British population.
Unfortunately, as readers may be aware, there has recently been a massive wildfire at Hatfield Moor, with about half the site (700ha) being burnt. Although quickly attended by the Fire Brigade and site staff, a brisk wind blew the fire from west to east across the site. At of the time of writing, the fire is under control after 2 weeks of intensive effort, led by the Fire Brigade, and supported by NNR staff, some of our local contractors, and even a water bombing helicopter. The fire is now reduced to a number of smouldering hot-spots, but peat fires are deep seated and very hard to finally extinguish, so we expect to be dealing with small flare-ups for some weeks.
The fire has caused huge destruction across the site, with many areas of heather scrub and woodland being burnt, and a significant effect on the many animals such as adder, and other wildlife. But the fire has fortunately largely missed the most important areas for nightjar, although we expect there will be an impact on them this year. The birds have only just started arriving after their migration, so are unlikely to have started nesting, but some of their traditional nesting areas have been lost. Whether those birds will go elsewhere, or whether they will try to cram in to the remaining areas we don’t know, and how much of their feeding areas have been lost or diminished is unknown. Ongoing research is looking into how the birds move between different sites, and how much the populations mix, but this is still at an early stage. Overall it seems likely that there will be fewer birds nesting on Hatfield this year.
Looking to the longer term, we think populations will recover quickly. Much of the dryer habitats they like will regrow, and in the early stages may even be more attractive to nesting birds, as the vegetation will be shorter and less dense, but this will depend on how deeply the peat has burnt, and how quickly the heather recovers. Where the fire has skimmed over and not burnt out the roots, the heather will start to re-establish very quickly, but more deeply burnt areas may take some years to regain a good heather cover. Managing the site better to reduce fire risk, by creating wide fire breaks, will also improve the site for nightjar by managing the heather more, and creating the mixture of low and higher areas the nightjar like.
So overall, while we can be optimistic about the future of nightjar on the site, the fire has still been a tragedy for the Moors.
About the Author
Tim graduated from Wolverhampton Polytechnic with an Applied Biology degree in 1986 and worked as senior botanical surveyor for the Montgomeryshire Wildlife Trust, spending 18 months surveying around 80 second tier wildlife sites. He moved on to the adjacent Shropshire Wildlife Trust, working with second tier sites, planning casework and ended his year with the Trust preparing management plans for woodlands in the Severn Gorge.
Tim joined the Nature Conservancy Council in March 1990 as an assistant to the conservation officer covering the West Midlands, again looking at second tier wildlife sites, but this time in a much more urban setting. In April 1991, on the formation of English Nature he moved to Colchester, to become a Regional Urban Officer, covering Essex, Suffolk, Norfolk and Hertfordshire. His role was to promote Urban Nature Conservation and work with a wide range of partners on policy and practical management of urban sites.
Tim moved back to Yorkshire in 1992 and for the next 6 years was Conservation Officer South Yorkshire, dealing with the full range of English Nature’s activities in the County looking after SSSIs (including Thorne and Hatfield Moors), providing advice on wildlife issues and on planning applications. In late 1998 he changed roles to take on Biodiversity issues for the Team, and spent much of the following 4 years encouraging and assisting with the development of Local Biodiversity Action Plan groups and plans. Ultimately, Tim reverted to covering South Yorkshire until the formation of Natural England in 2006, adding Agri-environment scheme and SSSI work in the Doncaster area.
Tim has been the Senior Site Manager for the Humberhead Peatlands NNR since the beginning of 2016.
Join us again tomorrow, Friday 12th June at 8pm on the Land Lines website, when we will be releasing photos of some lovely artwork, notes and creations relating to the nightjar from students at Hatfield Woodhouse Primary School!