Why ridge lines give you the best odds

Ridge lines are the highways of the upland edge. Air warmed over the valley floor spills up the slope, and any bird that wants to travel without spending much energy will ride it. That is why a footpath following a heather shoulder, a limestone escarpment, or the top of a wooded scarp will often put you above two or three raptors in a single afternoon. On a breezy day the birds hang almost motionless into the wind, which gives you all the time you need to look at them properly.

The trick is not to walk faster than you look. Most people stride along a ridge and the birds see them long before they see the birds. Ten minutes standing still at a gate is worth an hour of striding.

Reading the silhouette

When a bird is high and backlit, shape is everything. Forget colour and learn the outline.

• Red kite: long, narrow wings with a sharp bend at the wrist, held angled back like a bow. The tail is the giveaway — long, and forked, twisting constantly as the bird steers. Look for five splayed "fingers" at each wingtip.
• Buzzard: broad, rounded wings, often held in a shallow V when gliding, and a short, fan-shaped tail. The head and neck project noticeably in front of the leading edge.
• From underneath: a kite shows pale, almost white patches at the wrists on a darker underwing. A buzzard shows dark, solid patches at the same points, plus a barred belly on many birds.

A kite viewed from below often looks pale-headed and silvery; a buzzard reads as a solid brown bird with a paler, barred chest. If you can only remember one thing, remember the tail.

Flight — the difference is in the rhythm

Watch for a minute rather than a second. Buzzards are steady and deliberate. They flap with deep, stiff beats, glide on flat or slightly raised wings, and hang into the wind with the tail fanned and the head down, kestrel-like, before dropping. They will sit on a fence post for twenty minutes and then stoop heavily onto a rabbit or a worm with a businesslike air.

Kites are looser and more buoyant. They steer with the tail, rocking slightly from side to side, and often drift without any apparent destination. Wingbeats are slower and lazier, and they frequently soar with the wings pushed forward and the tail twisted to one side. Buzzards circle tightly and neatly; kites wander. Kites also gather — two, five, sometimes a dozen over one field or near a communal roost wood — whereas buzzards are usually alone or in pairs.

Calls that carry across the valley

Sound often finds them before your eyes do, especially from late winter into spring.

• Buzzard: the classic mewing "pee-yay", drawn out and plaintive, repeated every few seconds on the wing. It is the sound of a windy afternoon over a copse.
• Red kite: thinner and higher — a whistled "wee-oo" that rises and then falls. Breeding birds make a whinnying tremolo, like a small toy whistle spun in the air.

Both can be surprisingly far away when you first hear them. Get into the habit of looking up and turning slowly, because a call from directly overhead is easy to miss entirely.

Fieldcraft on farmland and moorland edges

Good views come from being unremarkable. A few habits will double what you see.

• Walk into the wind where you can. Raptors hunting a ridge face into the breeze, so a bird working towards you is far less likely to spot you first.
• Use cover. Hedgerows, drystone walls and the dark side of a conifer belt break up your outline. Avoid stepping onto a bare skyline yourself.
• Stop at gateways and stiles. They are natural vantage points, and birds are used to people pausing there rather than ploughing on.
• Scan with the naked eye first, then lift your binoculars. Sweep in slow horizontal bands, checking the air above the ridge, not just the ground beneath it.
• Pick your hours. Early morning and the middle of a warm afternoon are best, when thermals lift and birds are on the wing. Mid-afternoon in high summer can be strangely quiet.
• Note the weather. A light westerly after rain, with cloud breaking, is often the finest kite weather you will get. In a flat calm, expect birds to sit tight.

A short list to carry in your head

Long forked tail and bent-back wings means red kite. Short fan tail and broad, rounded wings means buzzard. Pale wrist patches and a twisting, ruddering flight: kite. Dark wrist patches, a hunched glide and a fence-post habit: buzzard. A thin rising whistle: kite. A drawn-out mew: buzzard.

None of this replaces time in the field. Give a ridge line an hour of quiet attention on a breezy afternoon and the two birds will separate themselves for you, almost without effort. Once you have seen a kite twist its tail against the wind, you will never mistake it for anything else.