The greatest wildlife spectacle on earth is undoubtedly the wildebeest migration in East Africa .

Over 1.5 million wildebeest and hundreds of thousands of zebra and Thomson's gazelle follow the grass and the rain in a year-long trek from the Serengeti to the Masai Mara and back.

I have travelled to Kenya and Tanzania to follow this mass movement on several occasions, but there are other migrations that happen closer to home every winter, albeit on a smaller scale.

Like the wildebeest, some of our Yorkshire birds migrate in order to follow food and weather. Some, like swallows and house martins, leave to undertake epic journeys back to Africa .Others, like waxwings and fieldfares, flock in to escape the icy cold of the Scandinavian winter and gorge on our berries.

The next few months, in particular, promise to be a good time to spot these beautiful birds as harsh temperatures are forecast for Northern Europe and Russia .

Even regionally, mini migrations occur.

Skylarks are resident in the UK all year round but will often leave open moorland, such as the North Yorkshire Moors and Pennines , when temperatures drop. They usually head for low-lying areas where they can be assured of less punishing weather and more food. Meadow pipits also leave the moors in search of warmth – many travelling as far as the continent.

As with the African migration, when the herds move on, the predators follow. Similarly, as the migratory birds travel, the birds of prey that depend on them also follow suit.

One bird of prey that is particularly affected is the merlin. For most of the year, its main quarry is the meadow pipit. But, when the meadow pipit ups sticks for winter, the merlin is left with no choice but to leave its traditional moorland haunt and follow the food.

Now is a good time to spot this super falcon. You can find it almost anywhere there is suitable hunting ground. It favours low-lying marshland, estuaries and coastal areas where there tends to be an abundance of small birds.

The size of a mistlethrush, a merlin packs plenty of raw power into its diminutive frame and two foot wing span. Its nearest relative is the kestrel, but a merlin is readily distinguished by its shapelier and shorter wings, which can look like a mini-peregrine in silhouette.

A merlin is smaller than a sparrowhawk, which has broad round wings, and is more agile than both of these birds of prey. In flight, it has quick flickering wing beats followed by irregular glides.

People also confuse the merlin with the hobby, since they are the two smallest falcons in Britain . But it's easy to spot the difference when these birds are hunting.

The merlin hunts like a sparrowhawk zipping along hedgerows and dry stone walls. Whilst the hobby hunts like a peregrine, soaring in the sky and then stooping down with sweeping, scythe-like wings and is often seen catching insects and eating them on the wing.

You don't have to worry about confusing the two at this time of year, though, since the hobby is migratory and has already left with the swallows – its main quarry – and will return with them too.

The hunting technique of the merlin is more persistent than any of our birds of prey. Once it has locked on to a target, it doesn't give up. And pursuits can be prolonged. The merlin will tail-gate its quarry until it is exhausted.

One wet and windy winter's day, I was driving along close to my home in Thixendale when I spotted this aerial combat ahead of me.

I knew straight away that it was a merlin chasing a small bird and not a sparrowhawk attack, even though sparrowhawks are more likely in this area.

The small bird was climbing higher and higher – an unusual escape plan. Most small birds head for cover when under pressure.

As I got out of my car I could hear the clear, loud singing of the merlin's quarry. It was a skylark.

The song of the skylark is pure bravado, much like the pronking of a gazelle on the African plains. It sounds as if it is saying: ‘catch me if you can', or, in modern speak, ‘am I bovered?'

As the skylark climbed, so did the merlin. But, the merlin needed to get above the skylark in order to launch its attack. They were already 300 feet up and at last the merlin gained some height advantage. He started a spectacular set of stoops.

To my amazement the skylark kept singing, twisting and turning to avoid the falcon's reach. Then the two birds climbed higher still, so that they were almost impossible to see with the naked eye. And still the lark sang on.

After a few minutes of combat and 30 or more stoops, I thought these birds must be getting tired. Sure enough, the skylark's tune faded, and, as it did so, the merlin picked up the pursuit. Tail-chasing the lark like a guided missile, it mirrored every aerobatic move the lark made.

The lark knew it was in trouble and plummeted to the ground with the falcon hot on its heels. Then both disappeared into some trees and out of sight.

I was so fascinated by the spectacle that I had not noticed that I had been soaked by the driving rain until the battle was over.