If you go down to the woods today...

Nope we didn’t have to go in disguise and there were not all the teddy bears having a picnic, but this time we were definitely in for a big surprise. 

Sunlight from a golden evening streams through the trees, the dried crunchy leaves and needles scattered on the forest floor glow in the dappled sunlight. The trees are bushing out with bright green leaves, mixing with dark evergreens of the pine trees. A rustle in the fallen leaves and two men appear from the open grassy track, carrying a ladder, and head into the shade of the trees. They move as quietly as possible, carrying their load. Manoeuvring the ladder against one of the tall trees, one begins to climb to the large nesting box attached to its trunk. With care he opens the side hatch and peers in. The box is a Tawny Owl nest box, one of 20 put up around the Forest in a new monitoring project. 

Sunlight streams through as the guys check the box

At the bottom of the box on top of the fresh sawdust placed on its wooden floor, is a deep cosy nest of greyish, soft down and hidden beneath a small layer of feathers are 10 creamy eggs.  

Here is the surprise. The eggs do not belong to Tawny Owl, or even Stock Dove perhaps the other species expected to inhabit the boxes. They do not even belong to Jackdaw, although that would be unusual given the location within the Forest. No, the nest belongs to a Mandarin. A beautifully exotic duck whose usual range is in East Asia but that was introduced in the early 20th Century and is now a naturalised resident. 

It seems odd, a duck nesting in a tree cavity. But there are many that do, including our native Goldeneye. 

Mandarin nest. Photo: Mike Toms

But there it is all nestled within the squared walls of our box. This time the female is not present and has carefully covered the eggs to keep them warm in her absence. Carefully the ladder is removed and the team retreats, we will return again to check the nest again with the hope of catching the female as she leaves, but also to check that the ducklings have climbed out OK. For that is how it must be, the ducklings will claw up the inner wall of the cavity and launch themselves out of the hole! Good job they are so soft and ‘fluffy’!

A few days later and the glorious sunshine had vanished to be replaced by a rather dull, grey morning. But once again, moving softly and quietly between the trees and over the rustling leaves the team with the ladder returns to the tree and the box. This time we are in luck, the female is in the box and we are able to catch her. What a beautiful bird. While the male may have all the flashy colours, the subtle beauty of the soft greyish brown feathers, mottled chest and big dark eye of the female is captivating. 

The beautiful female Mandarin

We let the female go with an extra bit of bling in the form of a uniquely identifiable ring. She will return to her nest and very soon those little ducklings will be making that leap of faith. It’s then a long walk through the forest leaf litter and grassy tracks to the nearest water of the river. 

A night in the forest

I may be 38 weeks pregnant but that is not going to stop me following my interest and passions, within reason of course. 

So 8pm on a Thursday night finds me standing in chest high bright green bracken in a patch of forest. On all four sides the tall dark green of dense pine trees surrounds this opening. Above the darkening sky is overcast with just a hint of pale gold touching the underside of some clouds as the sun sets. It is very still, not a breath of wind troubles the pine needles or the curling fronds of bracken. Beneath the canopy brown needles have collected along with dead branches that crunch underfoot. Out in the patch beneath the bracken the dusty soil kicks up with each footstep as we head through the bracken in search of a suitable place to position our net. 

In the forest setting up nets

The last few strains of bird song drift through the air, a robin, song thrush and the odd woodpigeon settling down for the night. With the net set we settle on the carpet of pine needles just within the shelter of the trees and wait. The colour drains from the surrounding landscape, the bright green of the bracken turning grey. Against the darkening sky the silhouette of a tiny bat darts across our view, twisting and turning with fluttering wings. A larger bat dashes by, a bold black dot with distinctive shaped wings. Amongst it all a new call begins to echo across the forest and its open spaces. A continuous churr followed by a soft coohick. Then there is the sound of clapping before the source of the unusual sounds is revealed. From the trees and swooping overhead in almost silent flight, comes a dark shape with pointed wings and a long tail. The flight can be direct, but also bouncy, with the bird swooping low to skim the bracken before lifting back up and away over the trees. Still although out of sight the distinctive churr picks up again. This is the nightjar. 

Unfortunately and it seems like many of our distinctive migrant birds the nightjar has experienced major population declines. Fortunately like many of species there are individuals and organisations out there working to understand these declines and the movements and requirements of such species. Nightjars in Britain have actually increased in breeding numbers in recent years (whoop!) thanks to a number of conservation measures. However they are still Red Listed and we still know very little about their movements outside of the breeding season. For a number of years the British Trust for Ornithology has been conducting a tracking study of the nightjars looking at not only the habitat they are using for nesting and feeding during the summer on our shores, but also where they are going during the winter. We know that the species winters in Africa and that they pass through places like France and Spain enroute, the tracking allows us to work out the detail.   

And so with a couple of birds drifting around us it was time to try and catch one. With the help of a system playing the churring call of the male it was not long before one came into investigate and was caught in our mist net. 

The type of tags the team from BTO have been using are known as geolocators, these record light levels allowing position to be calculated by day length and the time of solar noon. More recently novel GPS tags have been used. Both require the birds to be re-caught in order to down load the data. Hence the intensive effort each breeding season to catch the birds. 

Tonight our bird did not have a tag and was also not ringed. But this gave the team the opportunity to attach one to it in order to track its migration south. 

A beautiful nightjar

Up close the nightjar is so cryptic it is stunning. The grey-brown mottled plumage with fine streaks on the breast provides the perfect camouflage against the scrub, heath and dead branches of the forest floor during daylight hours. We know it is a male from the brilliant white patches on the wing and tail. The fresh, consistent plumage indicates it is an adult (born at least 2 years ago). Large dark eyes sit on a relatively large head that appears all feather and has a tiny beak with sturdy bristles along its closed mouth, used for detecting its prey at close quarters. But that mouth holds a secret, give it time and the tiny beak will open revealing a huge wide open gape capable to engulfing moths. 

With a new metal ring and a tag securely attached the bird is ready to return to the dark forest. It sits unhindered for a moment on my hand, its eyes getting re-accustomed to the dark after the torch light. It feels like no weight at all. Then with one dip of the wings it is off becoming once again the churring, wing clapping shadow against the night sky, only this time it will also be collecting valuable data to help its entire species.

An Owl in the Forest

To be honest even for me it was the wrong side of 4 am. Light was seeping through the forest as dawn broke, turning the misty trees various shades of grey. For the first time in a long time I could hear the dawn chorus, a cacophony of birds waking up to a gloomy day threatening on its promise of rain.

The convoy of cars made its way down the dirt track, a thick wall of tall pine trees crowding in on both sides, their tops swaying in a slight breeze. Suddenly the trees fall away, opening up into one of the many clearfell patches within the forest. Tall waving grasses and dense, thick scrub and bramble replace the wall of trees alongside the track. Looking out across the clearfell, rows of stumps line the patch, a tumble of roots and limbs of felled trees. The odd tall tree remains, standing sentry overlooking the neat rows of newly planted pine trees, merely knee high and often overshadowed at this stage by the willowy grasses that are heavily laden with moisture. 

As the convoy slows, something swoops out from the trees, catching the lead driver's eye before a sickening thud is heard from the rear of the van. The group stops and the driver gets out retracing his route. Half expecting to see a pheasant, notorious for their suicidal flights out across roads, there is surprise as he approaches to find, crouched on the ground by the side of the track, a rather stunned looking tawny owl.

Tawny owl ringed in Thetford Forest

Close inspection reveals the bird is absolutely fine if a little stunned the convoy having been moving so slowly. And while this is not the most conventional way to catch owls, we could not miss the opportunity to put a ring on this one. Very few tawny owls are ringed in Thetford Forest (not for the lack of trying). In fact this is the first free flying bird to be ringed by the Thetford Forest Ringing Group, with only chicks in the nest having been ringed before the group formed. There are however many questions about the spatial distribution and productivity of tawny owls in the Forest, and how this relates to other owl species utilising this landscape such as the long-eared owl.

This owl turned out to be a young bird, fledged this year. Tawny’s breed early, with territories established during winter, and the first eggs usually being laid between February and March. Young birds leave the nesting hole after 25 days before they can fly, hanging around on branches near to the nest for another 10 days or so. This bird was well beyond that, being able to fly, even if it was not quite so well coordinated as to avoid big moving vans….

And then with a soft swish of silent wings the owl swooped away from the road and disappeared into the darkness of the maze of tree trunks.

This was not however the reason for getting up at the crack of dawn on a bank holiday weekend…. that was to try and catch a cuckoo, something that will have to wait for another day as the birds remained stubbornly out of the net and the promised rain finally arrived.

Larking Around

Only recently had the trees been felled, leaving a mosaic of sandy soil, mossy grass, patches of dark heather and tangles of twigs and branches. From the main road this seemingly barren landscape sloped up to the tall dark green conifer trees that surrounded the patch on three sides. While it may seem an extreme change this is the cycle of this forest where trees are planted and felled on a rotation. Add to that the process of returning areas to more natural grassland heath and more of such open areas can be found amongst the blocks of trees. For 100 years ago this landscape was totally different. The entire area was open with grass and heather heaths, open sandy areas, low intensity arable farming and abandoned fields. Rabbits in particular were farmed in large enclosed warrens. Following the First World War the Forestry Commission began the process of afforestation, planting hundreds of hectares of Scots and then Corsican pine to provide a reserve of timber for a country whose trees had been as ravaged by the demands of war as its people. Today the whole of Thetford Forest is a patchwork of pine plantations, broadleaved trees and heath land, and is managed not only for timber, but for recreation and wildlife.

Woodlark carrying food for its chicks

Such barren looking patches of clear fell and grassy heath provide important habitat for a number of scarce breeding birds, including the woodlark. The tufts of short grass, close proximity to bare soil and good high posts for singing, are all perfect for woodlarks to set up home during the summer.

Knowing an area is good for breeding woodlark, seeing a pair there with the male’s sweet song of melancholy notes which includes a lu-lu-lu, giving the bird part of its scientific name Lullula arborea, is one thing. Finding its nest is a whole different ball game, one of patience and knowledge. Even knowing there is a nest within a few square feet in front of you, it is still hard to see, such is the excellent cryptic nature of nest and chick.

A beautiful woodlark nest

But there nestled amongst the grassy stems is a tightly weaved nest, in which four greyish brown chicks are squeezed in. What a privilege to be allowed to approach and view such a nest, which is done under strict licence. Monitoring of this species has never been more important. Since the early 1980s the range and population of woodlark in the UK has actually increased following a severe decline, but it is still comparatively rare and its breeding range restricted. Forestry plantations form a key part of this increase, but interestingly in the Forestry areas of Norfolk and Suffolk numbers of woodlark are in decline. Understanding more about the movements, breeding success and habitat use of birds in such areas is contributing to maintaining and increasing woodlark numbers by feeding into management plans for the forest. To that end this, and other nests are being monitored from egg laying to fledging, and the chicks are being colour ringed to look at movements of birds and where they subsequently return to breed.

Feed me!

On returning these four chicks to their snug nest and stepping carefully away to a safe distance, we watch as both parent birds call with a soft ‘tlewee’ to each other, beaks full of recently foraged insects, before swooping in back to the nest. We turn to leave, happy birds, happy chicks, happy people.