Fenland wildlife does not perform on cue. A drain that looks empty in February can be heaving with duck in November, and the best sightings often come from standing still for ten minutes rather than walking another mile. The trick is knowing what should be around, where it tends to sit, and which small signs give away the animals you will probably never see directly.

What follows is a seasonal guide to the birds, mammals and insects of the drains, washes and wet meadows. It is written for people walking, cycling or quietly sitting on a bank with binoculars — not for anyone needing a rare-bird tick. Learn the common species well and the uncommon ones will eventually stand out by themselves.

Winter: the season of water and numbers

From November through February, fenland is at its most open. Vegetation has died back, water levels are typically high, and birds that spent the summer on northern tundra or Arctic coasts are here in force. This is the easiest time of year to learn wildfowl, because you can see them without leaves in the way and they are often concentrated on a few unfrozen water bodies.

Look for swans on flooded washes and shallow drains. Mute swans are resident and obvious, with their orange bills and curved necks. Beware swans, though: whooper swans arrive from Iceland and have more angular heads, with yellow running in a wedge down the bill. Bewick's swans are smaller and scarcer, and their yellow patch is usually smaller and more rounded. If you cannot separate them at distance, note the bill pattern and move on — swan identification improves with repetition, not with stress.

Duck numbers peak now. Wigeon whistle from wet grassland, teal cluster in tight groups on the edge of vegetation, and tufted duck and pochard dive in deeper drains and gravel pits. Goldeneye and smew turn up on larger waters in cold snaps.

Winter is also the best time for mammals, simply because you can see through the hedges. Look for:

• Otter spraints — dark, tarry droppings left on flat stones, bridge ledges and grass tussocks, often with fish scales and bones visible. They usually smell faintly of jasmine or fish, depending on your nose.
• Water vole latrines — small piles of green, blunt-ended droppings on ledges just above the waterline, plus neat nibbled stems cut at a sharp angle.
• Muntjac and roe deer tracks — cloven prints in soft mud along droves and field edges, often with a well-worn path running parallel to a ditch.
• Field signs of brown hare — flattened forms in rough grass, and droppings that are rounder and paler than a rabbit's.

Barn owls hunt by day more often in winter, when short daylight forces them out early. Watch fence posts and ditch margins from mid-afternoon.

Early spring: sound before sight

By late February and March the fen starts to announce itself. Chiffchaffs arrive and sing their name from willow scrub. Lapwings display over wet fields, tumbling with a wheezy, peevish call. Redshank and curlew return to damp grassland, and oystercatchers pipe over gravel workings.

This is a good period for amphibians. Common frogs spawn first, leaving clumps of jelly in shallow, sun-warmed corners of ditches and garden ponds. Common toads follow, laying long strings rather than clumps. Great crested newts are protected, so look without disturbing: a torch after dark can reveal them hanging in clear water, but do not handle them or move spawn.

Late spring and summer: insects, reeds and reedbed birds

From May, the fen becomes a different place. Reeds grow tall, ditches fill with water plants, and insects take over as the main spectacle. Warm, still, overcast days are often better than blazing sun — dragonflies and damselflies fly less frantically and settle more readily.

Learn a few species and the rest become manageable:

• Banded demoiselle — a metallic blue-green damselfly with dark, broad wings, drifting low over slow water from late May.
• Four-spotted chaser — brown, with dark patches at each wing base, perching on reed tips.
• Emperor dragonfly — large and blue-green, patrolling drains at height, rarely landing.
• Common darter — red-brown, perching on fences and paths well into September.

Reedbeds hold reed warbler, sedge warbler and reed bunting through the summer. They are hard to see and easy to identify by song once you know a few phrases: reed warblers repeat a steady, churring rhythm; sedge warblers ramble and imitate. Bitterns boom in spring but are far more often heard than seen. Listening is a legitimate form of wildlife watching.

High summer on the washes and meadows

July and August are quiet for birds and loud for everything else. Grasshoppers and bush-crickets fill rough grassland, and brown hares are visible in hay meadows in the early morning. This is the best month for water voles along clean, slow drains with plenty of soft bankside vegetation; sit still at dusk and listen for the loud plop of one entering the water.

Bats are the other summer highlight. Pipistrelles emerge early and flutter low and erratic along tree lines; noctules are larger and fly straight and fast, often high overhead. A simple heterodyne bat detector can turn an invisible evening into a recognisable one, though exact identification takes time.

Autumn: passage and departure

September and October bring movement. Swallows and martins gather on wires and over water before leaving. Waders pause on muddy margins — green sandpiper, ruff, black-tailed godwit, snipe. Water levels are often low enough to expose mud, which is exactly what these birds need.

Fungi appear on wet woodland edges, and berries and seeds draw in winter thrushes. Fieldfares and redwings arrive from Scandinavia, often first heard as thin, high calls overhead at night or on murky mornings.

How to look, wherever you are

The techniques matter more than the location. Standing quietly at the edge of a drain for fifteen minutes will usually show more than marching a mile along it.

1. Walk into the sun where you can, so birds are lit rather than silhouetted and you are less visible against the sky.
2. Stop at corners, bridges and gates. Animals use these pinch points too, and you get a clean view without trampling banks.
3. Scan slowly. Sweep the far bank with binoculars, then the near margin, then the water surface, then the sky. Repeat.
4. Use your ears first. Pishing, clapping or playing recordings is not necessary and can disturb breeding birds — patience does the same job.
5. Check the edges. Most wildlife in a drain is within a metre of the bank, not in the middle.
6. Keep a notebook or phone note with date, place, weather and species. Patterns emerge after a season or two that no guidebook will tell you.

Stay on public rights of way and permissive paths, keep dogs under control near water and nesting birds, and leave gates as you find them. Disturbance costs animals energy they cannot spare, particularly in winter and during the breeding season.

A few practical notes before you go

Binoculars of 8x42 are a sensible general choice for fenland, where light is often flat and views are long. Waterproof boots are not optional between October and April. A torch is useful for evening walks, and insect repellent earns its place near standing water in summer.

If you are watching from a boat, a canoe or a paddleboard, keep well back from banks and reed edges, where nests and burrows are easily damaged. Avoid approaching stranded or apparently sick animals; report concerns to the relevant wildlife organisation or the landowner rather than intervening.

The fen rewards the same visit repeated through the year. Pick one drain, wash or wetland near you and go back once a month. By the time you have a full twelve months of notes, you will know more about that one place than most guidebooks could ever tell you.

Photo: jhenning / Pixabay