Special places, hidden stories

Wildmoor in storm by Roger Stace

The BBOWT team tell us about their favourite spots and what makes them so special. This month: nightjars and scrub bashing on Wildmoor Heath

In this blog series members of our team share a photo of their favourite spot on our reserves, and tell us the story behind it: what makes it so special, and the work that goes in to maintaining it. There’s always more than first meets the eye!

In our second report from Wildmoor Heath, Roger Stace introduces us to the fascinating world of nightjars, and the land management needed to maintain their breeding habitat.

Nightjar by David Tipling

Nightjar by David Tipling/2020Vision

RS: If we’re talking about Wildmoor we really need to talk about nightjars. They’re such fascinating birds – they’re crepuscular, so they’re most active at dawn and dusk, but then they are somewhat active through the night as well. They’re ground nesting, and lay their eggs on the edge of heather or bracken – the eggs are highly patterned so they’re well camouflaged when they’re on the ground.

They are quite strange looking birds with a really broad beak, and massive eyes when they’re wide open at very low light levels (usually you’ll see them with their eyes only partially open). They fly over from Africa in April or May, stay here to breed, and make their way back in September time. Heathland is one of the key habitats for them, although you do occasionally find them in big forestry clearing operations, things like that.

Male nightjar by David Tipling

Male nightjar by David Tipling

They feed on insects – they hawk, meaning they fly around hunting on the wing, and they’ve got little bristly hairs inside that broad beak to enhance their ability to catch moths or other flying insects. That means the nightjars flying around the night that we were moth trapping (see Part 1) will have been eating the moths that we were trying to identify! But that’s one of the main reasons that moths are so important, just the sheer volume of food they and their caterpillars provide for birds.

The call of the male nightjar is called a churr, a kind of rattling call. He basically sits in the top of a tree and will give this rattling call repeatedly – the first time you hear a nightjar out on the heath it’s a really otherworldly experience, there’s no other bird call in this country that’s anything like it. It’s almost like a didgeridoo, they just keep going and going using circular breathing, and you can hear the pitch change which I think is where they’re breathing in and out. They can go for minutes on end without stopping.

Nightjar churring by Roger Stace (sound up!)

Then if you’re lucky enough to see it, you get the males and females flying together - the males have these very bright white flashes on the underside of their wings. I’ve had fantastic views of them flying together when the male does the wing clap as well – they knock their wings together over their head and make a loud clapping noise that you can hear right across the heath – that’s their courtship display. They’re amazing, I absolutely love it.

Wildmoor in storm by Roger Stace

Wildmoor in storm by Roger Stace

JM: I’ve seen Wildmoor described as a ‘fragile’ site – why would that be?

RS: First of all, the hydrology of the mire is a very delicate thing, so if it started to dry out you’d very quickly start to lose the key species. Also if you got too much runoff of polluted water, that would also be hugely detrimental.

Nightjar on nest by David Tipling

Nightjar on nest by David Tipling

On heathland in general the bird species are ground nesting, so they’re very vulnerable to disturbance, especially from dogs and people exploring off the paths. Even a dog that's perfectly behaved just by its presence could disturb a nightjar nest on the ground – the bird will potentially fly away, abandoning the eggs to chill and perish.

JM: What conservation management do you do on this site?

RS: Heathland is effectively a manmade habitat – certainly the heathland we see in our county was created by people’s subsistence living off the common land. They’d have their two cows and three geese that would graze a bit of heath near their home; they’d cut the gorse and birch for firewood, the bracken for bedding or food, and by doing all that just to survive they created and maintained these open habitats for hundreds of years. The wildlife found its way into these heathlands, and developed and adapted to utilise these open habitats.

Sphagnum moss and heather by Mark Hamblin

Sphagnum moss and heather by Mark Hamblin

So what we’re doing now as habitat managers is effectively recreating some of that work that people used to do to survive by clearing scrub: cutting the bracken and heather, and scraping the ground (people would have dug heather turves for fuel as well). We’re creating that variety, the bare ground and the open habitat without scrub, that mosaic of different aged structures of heather, scrub, and some areas that are very open - that’s what the wildlife we’re looking to conserve is reliant on.

And that variety is also what makes it a really fun place to trap moths – good open habitat, and lots of scrub as well which is very important for moths, providing shelter and food plants for the caterpillars. You’d never actually want to get rid of all the scrub, just it tends to take over if we do nothing.

Wildmoor boardwalk by Roger Stace

Boardwalk at Wildmoor Heath by Roger Stace

The key to our management is our work parties over the winter – we call it scrub bashing, cutting lots of it down and having a bonfire; cutting areas of heather and raking it off so that it regrows. The work party isn’t happening right now of course because of lockdown, but do look out for it back up and running next winter. We also usually run several nightjar surveys through the summer, where we have spaces for members of the public to come along and join in, so do look out for those when it becomes possible again.

Roger Stace has worked for BBOWT across all three counties, and is currently Land Manager for West Berkshire.