BOUNTY HUNTERS

Brian Pike reports on three of the Dales’ commonest birds of prey

irds like robins, blackbirds and blue tits have UK populations numbered in millions, but even our most successful bird of prey, the common buzzard, can only muster a population of some 70,000 breeding pairs. And when it comes to rarities like the goshawk or the merlin we’re talking in terms of hundreds of pairs rather than thousands.

Here in North Yorkshire the three birds of prey you’re most likely to see on the wing by day are the common buzzard, the kestrel and the sparrowhawk. And winter’s as good a time as any, if not better, to spot them. Now that the days are shorter, these sharp-eyed hunters have to concentrate their efforts at finding food into a far smaller window of opportunity than during the bright and balmy summer months.

HEDGEROW ASSASSIN The sparrowhawk

Although it’s the least common of the three species, the sparrowhawk is the bird of prey you’re most likely to see in your back garden. And that’s because our familiar garden birds – including sparrows, tits, finches, robins, blackbirds and pigeons – all represent potential meals for it. If times are hard the sparrowhawk will also feed on small mammals and invertebrates, but it’s other birds that it is supremely well adapted to catching.

The sparrowhawk’s favourite hunting strategy is to ambush its prey by dashing out from under cover and taking the unfortunate victim by surprise. It is a supremely fast and agile bird, capable of flying through narrow gaps between branches and changing direction in a split second.

Male sparrowhawks are substantially smaller, faster and more manoeuvrable than females, and they generally prey on smaller birds. Females are larger and slower, and consequently hunt correspondingly larger, slower prey, including relatively hefty birds such as jackdaws, pheasants and partridges.

If you’re fond of watching the small birds that crowd around your bird feeder you may not be entirely delighted to spot a sparrowhawk in the neighbourhood. However it’s worth reflecting that sparrowhawks, like most apex predators, tend to take slow, weak, sick or injured birds – in other words birds whose long-term survival prospects are poor. Sparrowhawks and songbirds have coexisted for thousands of years, and the main threats to bird populations today are habitat loss and environmental pollution rather than other birds.

DIVE BOMBER The kestrel

From a bird that you may well spot from your back window to one you’re most likely to glimpse through your car window: the kestrel.

Kestrels are experts at hovering, and some of their favourite hovering spots are above roadside verges, especially motorway verges. Their chosen haunts reflect their diet, which consists predominantly of the small mammals – mice, shrews and voles – that live in the strips of largely undisturbed grassland flanking our major roads.

Kestrels’ ability to maintain a constant position without flapping their wings is an impressive feat, one that they achieve by facing into the prevailing wind and using the lift provided by the oncoming air current to precisely counterbalance the force of gravity. Hanging motionless in the air, kestrels can use their razor-sharp vision to detect the slightest hint of movement in the grasses below. When they spot a furry snack they dive – swiftly, steeply and decisively.

In the absence of mice, shrews or voles, kestrels will also take invertebrates such as earthworms and beetles. So acute is the kestrel’s eyesight that it can spot a beetle at a distance of 50 metres. Like cats, kestrels can see ultraviolet light, enabling them to spot the urine trails left by small mammals and thereby helping them pinpoint their prey.

Whilst kestrels are still relatively common, their numbers have halved since the 1970s. Intensive farming, and consequent loss of hunting grounds and nesting sites, may be one factor. Another is the fact that kestrels can be poisoned by eating small mammals that have consumed poison meant for rats.

HIGH FLIER The buzzard

Whereas kestrels are most often seen on the wing just a few metres from the ground, buzzards are at home at altitude. On sunny days you’ll often spot them in pairs or small groups circling on thermals high in the air. From their lofty position they often conveniently draw attention to themselves with their mewling, mournful calls. (If you’re in any doubt what to listen out for, there’s a useful recording on the rspb.org.uk website.)

© RSPB Images

OPPOSITE Female sparrowhawk TOP LEFT Common buzzard in meadow TOP RIGHT Female sparrowhawk feeding young in nest BOTTOM Kestrel landing on old trunk

That’s not to say you won’t spot buzzards at lower levels too, perching on trees, telegraph poles and fence posts. I even saw one in my back garden recently, but by and large they are birds of the open countryside – which is not surprising, given that one of their favourite foods, and a major component of their diet, is rabbit. Buzzards will also take other small mammals, including rats and weasels, along with frogs, snakes and mid-sized birds such as jackdaws, crows and pigeons.

Thirty years ago buzzards were a rare sight in the Dales; like kestrels their numbers had plummeted in the middle years of the last century. Unlike kestrels, though, buzzards have staged a comeback – a revival in part due to legal protection and a more tolerant attitude on the part of gamekeepers.

Other than the common buzzard, two other species of buzzard can be seen in the UK. The honey buzzard is a very rare summer visitor that is occasionally spotted on the North York Moors. Slightly more common, but still rare, is the rough-legged buzzard, a winter visitor that can be seen on and near the North Yorkshire coast from October through until April.

ABOVE Male honey buzzard BOTTOM Kestrel chicks in nesting hole