Always when I have visited Upton before it has been the height of summer and the place has been alive with insects: dragonflies and damselflies quartering the dykes, and butterflies skitting low over the nettles that blanket the woodland floor. This evening, one of the last of April, I would have expected summer to have almost arrived, but the strange, stunted spring has put paid to that. Nature is a couple of weeks in arrears, and despite a false promise of things to come a day ago, the wind gnaws at me as I get out of my car. Even so, I am excited at the prospect of walking around one of my favourite Norfolk nature reserves at an unfamiliar season; from the look of the empty car park, it seems I will have the place to myself.

Norfolk Wildlife Trust’s Upton Broad and Marshes is located between the villages of South Walsham and Upton, two miles northwest of Acle. Covering over 300 hectares, it’s a sizeable reserve, comprising a mosaic of different habitats: open water, reedbed, wet woodland, grazing marsh, and the exotic-sounding quaking bog. As well as its wealth of dragonflies, Upton is also famed for its plants, including being one of the few sites in the country where the exquisite fen orchid can be found. The site forms the heart of NWT’s Bure Valley Living Landscape, which aims to connect together parcels of important wildlife habitat into an impressive whole: already, the Trust has made several purchases of neighbouring land, and evidence of conservation improvements and management work are plentiful around the reserve.

From the car park, I head along a woodland trail. It’s quiet, apart from the wind, but now a chiffchaff – one of the most pioneering of summer migrants – pipes out its staccato song from somewhere unseen. I come to an open area where the reeds have been cut to encourage new growth, and admire a display of daffodils which bring a vibrancy to the early-evening greyness. Despite the breeze, it is an oddly tranquil scene, with the woods that border the clearing soaking up any stray background noise. I press on, along the side of a dyke. The water it holds is black, with a thick film of bubbles and scum floating on top, a reminder of all the nutrients and life below. When I approach more closely, an army of pond skaters whizz away across the oily surface. I carry on, the ground spongy, but firm underfoot; no need to worry about the quaking bog, a sign assures me, so long as I stick to the path.

A great spotted woodpecker passes overhead, drawing my attention with its sharp call, and a wren scolds at me from among a stand of stark ash trees. Now I come to a boardwalk and the wood opens out. Large towers of exotic sedge jut up like termite mounds, and I stop to examine a semi-rotted birch stump covered with strange, sculptural fungi. The sun has emerged from behind the clouds, and although the breeze is no less severe, the newly arrived brightness makes the scene different again: the green shoots look verdant, and spring really does appear to be on its way. A blackbird begins to sing and a rival replies, not wishing to be outdone. Abruptly, I am into a sea of reeds, one lone birch ahead standing guard in the middle of the path. I stop, to try and take in the tranquillity, but am shocked by a commotion from just off the path. A brown shape crashes away into the reeds and I know it can only be one thing: a dog-like Chinese water deer, an introduction from the Orient that now flourishes in East Anglia.

As I carry on around the circular trail there are lots of signs of the hard work that goes into maintaining such an important jigsaw of habitats – pyramids of cut reed-straw cleared from paths and rides exposing the new growth below, shovelfuls of peaty soil dug from half-blocked channels, and piles of logs where willows and birches have been chopped back to stop the unceasing progression towards scrub and carr which, otherwise, would continue unabated.

I reach the grazing marsh, which looks resplendent in the late sunshine. The cattle glow orange-brown as they make their way, in unison, to wherever they are headed. Another deer gets up from among the juncus, disappearing into the distance like a frightened hare. I count five windmills on the horizon, reminders of the landscape’s human history: Clippesby, Oby, Upton, St Benet’s and Thurne Mills. From the reeds comes a loud rattling churring and I scan with my binoculars to find the culprit, who eventually pops into view – a sedge warbler, another long-distance summer visitor. In a few weeks, this reedbed will be alive with these smart, striped songbirds, as well as their plainer relative, the reed warbler.

Since my last visit new water-filled scrapes have been cut out among the reeds, and over on the marshes. Two lapwings spiral and dive above them, making the peewit calls that give them their local name – an odd, evocative noise unlike anything else. In the distance I can make out a lone little egret, pure white against the darkness of the land, and the V-winged silhouette of a marsh harrier strains the edge of my sight.

Returning through the other side of the wood, more life stirs. Pale yellow primroses paint the floor below feathery willow catkins. Stock doves cough out deep hooting calls as big flocks of woodpigeons scatter from the treetops, and two new summer migrants join the evening chorus: the bubbling chatter of a blackcap and the down-slurring song of a willow warbler. Almost back to where I began, I pass alongside another reed-fringed dyke and disturb one last water deer. This one though is braver, peering at me through a curtain of brittle stems, so close I can make out its distinctive facial pattern. I swear its down-turned mouth is scowling at me.

As I reach my car the light is slipping away fast, but there is still time to look up at the source of a twittering call: my first swallow of the summer.

[A version of this article first appeared in the Eastern Daily Press on 11/5/13]