Travelling Birds.

Forest and Bird, Volume 17, Issue 1, 1 February 1986, Page 28

Travelling Birds.

B* can sometimes be given the most odd-sounding names, but ‘godwit’ must surely be one of the oddest of them all. Originally, it was probably ‘Goodwight’, ‘wight’ coming from the old AngloSaxon word meaning creature. The ‘good’ refers no doubt to the popular presence of godwits on the menu at many an AngloSaxon feast. The Maori name for the bird is kuaka, and the fact that it has a Maori name at all shows that the godwit is not a recent import. In the past, English names were often given to New Zealand birds simply because the early settlers thought they looked like the birds back home, or because they were of the same family. In this case they are not only related, they are actually the same birds, for godwits breed in the northern hemisphere and come all the way down here for the summer. In fact they avoid winter altogether, for when they are nesting in Siberia and Alaska it is summertime there as well. Halfway round the world is a long, long way for such a small bird to fly, and just why the godwits should choose to come so far is one of the many mysteries that still surround the subject of bird migration. It is thought that the direction birds take and the places they go were learned thousands of years ago, and that although the climate and the landscape may have changed since then, the birds still follow the old ways. The reasons that they need to move at all have to do with the availability of food at different times of the year. A place that is good for breeding, with plenty of food for the new young chicks, may well turn into a barren icy waste later in the year, so

the birds must move to somewhere else when the season changes. In the case of the godwits, however, one would think that there must be plenty of suitable places that they could use between here and Siberia. An even greater mystery is how they find their way. Studies and experiments have shown that migrating birds can recognise landmarks, can navigate by the sun or the stars, and some can probably even sense the direction of magnetic north, but there are also species in which the young birds leave before or after their parents and seem to be able to find their own way to somewhere they have never been before. Godwits are among the migrant visitors

to New Zealand that come outside their breeding season, but there are also birds that come here to nest and return elsewhere in the winter. Notable among these are the cuckoos, although nesting is perhaps the wrong word for them as they do not build nests of their own. Both the long-tailed and the shining cuckoo lay their eggs in the nests of other birds, a habit, incidentally, that is by no means common to all cuckoos. Here in New Zealand there is not such an extreme difference between winter and summer as there is in other parts of the world, so many of our native birds have no need to migrate. There are some that do, however, the most famous being the little wrybill, the only bird in the world to

have a beak that is curved to the side. Wrybills nest on the shingle river beds in the east of the South Island, but they spend the winter on the estuary and harbour mudflats in the northern part of the North Island. Other New Zealand birds, like the South Island pied oystercatcher, are partially migrant, which means that some of them move north for the winter and others do not, as if they can’t quite make up their minds. To further complicate the issue, there are some recent arrivals from Australia like the silvereye and the welcome swallow who do not seem to have developed a migration pattern here, although they do migrate in their Australian homeland. All in all it may seem rather confusing, but migration is one of those fascinating subjects about which the more you learn, the less you seem to know! pet Most of the eastern bar-tailed godwits (opposite) arrive in New Zealand in September and leave again in March. They can be seen feeding on exposed tidal mud-flats and wet sand throughout the summer months. Numbers have been estimated at around 70,000 in the North Island and 30,000 in the South Island and Stewart Island. The bird in the foreground is in non-breeding plumage, the

other has the more colourful breeding plumage which you will see on some individuals towards the end of the summer. Each year some 10,000 or so godwits remain here for the winter as well, and it is assumed that these are non-breeding juveniles. Shining cuckoos (above) have been known to arrive from the Solomon Islands as early as

August, but most of them appear in the second half of September. They can be seen wherever there are grey warblers nesting, for it is to the grey warbler that this little cuckoo entrusts the care of its own young. The English name does not appear anywhere in the shining cuckoo’s song, but if you listen carefully you might hear the Maori name pipiwharauroa.