Western Morning News (Saturday)
Bird that comes with a twist
Charlie Elder goes in search of a unique finch of pine forests with an overlapping beak like no other
It is one of our most bizarre looking birds – curiously parrot-like, with a benttipped beak that suggests it has flown headfirst into a pane of glass. Yet despite its unique appearance, widespread distribution and idiosyncratic habits, it is not a species familiar to all.
The descriptive name is easy enough to remember, given its appearance: crossbill.
And to find them you need to find the right kinds of trees first – conifers.
A few days ago I paid a visit to a promising plantation forest in the heart of Dartmoor in search of this museum curiosity of a species, whose lifecycle is inextricably linked to that of the pine cones upon which it feeds.
You need the right tool for the job as a bird when it comes to beak shapes and sizes, whether probing for worms deep in the mud, harpooning fish, cracking open nuts, tearing into prey or chiselling a nesting hole in a tree. And the crossbill’s twisted mandibles are perfectly designed for extracting seeds from pine cones.
The bent and overlapping tips of the beak enable the crossbill to prise open the scales of ripening conifer cones, using its tongue to get at the seeds hidden within.
As such it spends all of its time in conifer forests. It favours Norway and sitka spruce and gregarious groups roam widely in search of ripe cone crops, breeding when times are plentiful.
Crossbills also clamber about a bit like a parrot, hanging acrobatically at the ends of branches as they plunder the pine seeds, and can be brightly coloured – the males brick red or orangey-yellow and the females greenish-grey.
But given these chunky finches feed high up amid the treetops, good views are not always that easy to come by, unless they fly down to ground level to a puddle or pool for a drink to wash down the dry seeds.
In the hope of coming across a flock I parked close to the Warren House Inn at the centre of Dartmoor and wandered down a path into the valley, following a stream to Soussons Plantation, which is criss-crossed by tracks and bridleways.
Evergeen forests, devoid of much undergrowth in the shadows beneath ranks of uniform trees, often appear at first glance to be devoid of life. But there can be plenty about, including specialist species adapted to the habitat.
And felled clearings between blocks of mature conifers also play host to a range of wildlife, from nightjars in summer to adders, bats and butterflies.
It was too cold to spot reptiles or butterflies, but there was a variety of birds to keep things interesting. Cutting through an area of birch and Christmas-tree sized firs, I came across a chatty gathering of long-tailed tits, working their way as a party from branch to branch in search of food.
At this time of year small birds of different species can join together in feeding flocks, with more pairs of eyes to find sources of food and watch for predators. And sure enough other species were close by, following the long-tailed tits. They included yellow and black finches called siskins, which are typically associated with coniferous forests, and a goldcrest, our smallest bird that sports an orange and gold stripe on its head.
Working its way up a tree trunk was a mouse-like brown bird with a white underside and a thin, curved beak – the aptly-named treecreeper. Their claws enable them to hop up the vertical sides of trunks with ease, while the
larger nuthatch can also climb head-first down trees, and there was one present, showing off its party trick.
I managed a quick photo of what I assumed was another siskin perching briefly on a branch and silhouetted with the sun behind it. Taking a closer look at my photo I was delighted to see it was in fact a small finch with a red forehead called a redpoll. I have seen them in this area before, but this was the first time I had ever managed to photograph one – even if, in this case, not knowingly.
Following a wide path deeper into the plantation forest I came across a great-spotted woodpecker and, as I stopped to admire it, I heard the distant sound I had been waiting for – the chip-chip-chipchip calls of a flock of birds: crossbills.
Crossbills have a hard tone to their call, which can be heard at a distance as they fly around at treetop height. The problem is they sounded to be heading away from me.
Negotiating shortcuts if you are unfamiliar with paths winding through the high-sided maze of a conifer forest is far from easy and after trying to track them for some time I was forced to give up and circled back, finding a way out of the plantation.
It was then that, by a stroke of luck, the restless crossbill flock decided to feed along the sunlit edge of the dense forest close by and arrived on trees flanking the path, along with plenty of siskins.
Given how tall mature spruce trees are, it was hard to get good views even through binoculars as they worked the cones among the uppermost branches. But passing birdwatchers with a telescope managed to focus in on them, and kindly allowed me a peek through the viewfinder at a female, her bent beak clearly visible.
They are certainly distinctive birds, and it always feels a treat to spot one. There may be some 40,000-plus breeding pairs in Britain, but given they move around it can be tricky guaranteeing sightings, even in good habitat.
They have a particular claim to fame north of the border, where they can be most numerous. Along with common crossbills, Scotland has its own endemic species of crossbill, the Scottish crossbill – with several thousand pairs found in that country and nowhere else in the world.
The Scottish crossbill was only distinguished as a separate species as recently as 2006, largely on the basis of its differing calls and song. It sports a slightly thicker bill than the common crossbill – though not as thick as that of the parrot crossbill which is a scarce visitor from northern Europe and breeds in very small numbers in Scottish forests. Three crossbills to tell apart! And quite a challenge given the differences are subtle.
I am fortunate in that I can claim with certainly that I have seen a Scottish crossbill, as I joined an RSPB researcher surveying the distribution of the species using sound detection equipment back in 2008. In fact, it was the first crossbill I ever saw, lured in by a tape recording to a pine tree in the snowy Highlands.
Down on Dartmoor there are no Scottish or parrot crossbills to confuse matters. Which was just as well given how hard it was to observe the flock I was watching with any clarity in the fading light.
Still, I was glad for a glimpse. They are certainly one-of-a-kind finches. And if you find yourself walking in a conifer forest and come across birds feeding high up amid the pine cones, it is well worth giving them a second glance just in case they are crossbills – fingers crossed.