A Confusion of Birdwatchers

Forest and Bird, Issue 309, 1 August 2003, Page 18

A Confusion of Birdwatchers

and

have worked

together on several books and documentary films.

—GORDON ELL

GEOFF MOON

The pipit and the skylark look alike but are quite different birds.

ut in the open country a small () fawn bird takes flight. Roused from the shelter of the rough grasslands where it feeds and nests, the bird rises to hang, fluttering in the sky. But what is it? Poets have made a common symbol of the skylark; the native pipit, however, lacks such a literature. It is very easy to confuse the two — they look so similar that it can be difficult to realise there are actually two different species of birds in the same habitat. Not only do these birds favour the same environment, they behave in a similar manner. Yet they are not even related — in evolutionary terms, skylark and pipit are so different that they belong in totally separate categories, birds without any scientific similarity. The skylark is an introduced European bird, the familiar subject of poetry and music, literary allusion and sentiment. The pipit or pihoihoi is a native bird, though it occurs in other parts of the world where it is known as Richard’s pipit. Skylarks were introduced to New Zealand by sentimental settlers. This is the songbird of the two, singing as ‘the lark ascending’ and continuing its song for many minutes as it flutters high above. The native pipit has a more restricted songbook: it is more likely to be heard calling ‘pipit from a fence post (though the skylark sings from there too). Unlike the skylark, the pipit tends to swoop in the sky, rather than maintain a particular position, and sings only as it returns to earth. It is easier to tell the difference between the two birds on the ground. The pipit is slightly longer and heavier than the skylark, with a longish tail, though the distinction is hard to grasp when a direct comparison is not possible. The pipit has a dark eye stripe.

A better field distinction comes from its song and flight behaviour, and from its behaviour on the ground. While both birds strut across open ground, the pipit continually twitches its tail up and down. The male skylark also has a tiny crest which it may erect as part of its display (see picture below). The skylark occurs naturally across Europe, North Africa, the Middle East and northern Asia as far as China. From there the birds may migrate southward in winter. The New Zealand pipit is related to pipits in central and eastern Africa, central and southern Europe, and Asia through to Australasia. Scientists now identify four subspecies in New Zealand; one on the mainland, the others offshore on the Chathams, the Antipodes, and Auckland and Campbell islands. In New Zealand, both birds inhabit a similar environment — short, often rough grassland from the sand dunes to the subalpine zone — but they use it differently. Pipits are found at greater extremes — at the higher altitudes, such as the exposed volcanic top of Tarawera, and in the sandhills and on the coastal strand.

The diet of skylarks includes vegetable material plucked from plants, some seeds and some invertebrates. The pipit feeds mainly on invertebrates. Both birds are ground nesters: this makes them vulnerable to predators such as magpies, falcon, rats, cats, hedgehogs and mustelids — the ferrets, stoats and weasels. The nest of the pipit is a deep cup ina stack of dry grass, in rough vegetation usually on a bank or slope. The skylark’s nest is neater, just a grass cup in a shallow natural depression in flat pasture, sometimes in very short grass. With their dull, fawn and creamy plumage the skylark and the pipit are well-disguised in the grass. While there are distinguishing marks in the form of different tail feather arrangements and subtle facial markings, it requires time

with a good field guide to judge the difference quickly. How then did these two unrelated birds come to look so alike and live in such a similar manner? In recent years, scientists have formulated the theory of what they call "convergent evolution. In this case two totally different birds have adapted to the same environment and responded to the same evolutionary challenges in very similar ways. By coincidence they have both developed similar features in their evolutionary struggle to survive.