The Life and Family Affairs of the White-Fronted Tern.

Forest and Bird, Issue 40, 1 May 1936, Page 12

The Life and Family Affairs of the White-Fronted Tern.

(By R. A. Falla)

A SMALL FISH IS FIRST OFFERING OF LOVE.

“SEA-SWALLOW” is a popular name throughout the world for birds of the tern family. Although closely related to gulls, terns are of more slender build, with long sharp beaks, long pointed wings, small feet and swallow shaped tails. The most plentiful kind in New Zealand seas is the whitefronted tern, so called because its “front,” or patch of forehead feathers just above the beak, is white. A splendid picture appears on the cover. It is found in coastal waters from the Auckland Islands in the south to the Bay of Islands in the north, and also occurs less commonly along the south coast of Australia.

The largest flocks and greatest number of nesting colonies are to be seen in the Hauraki Gulf. Here they are well known to sailors and fishermen as “kahawai” birds because of their habit of congregating in the air in a dense noisy flock wherever the surface is broken by shoals of small fish pursued by the larger kahawai. Under these conditions terns find fishing easy, but they are good divers and able to catch such small fish as pilchard and anchovy even without the help of the kahawai.

The birds begin to make preparations for nesting late in September and for some weeks about this time flocks of them seem to be engaged in examining likely nesting sites. When these are eventually chosen, they may occupy a variety of situations. Narrow rock ledges, shell banks, sandy beaches, cliff ledges, piles of drift wood, or even the decks of old barges and hulks are among the home sites likely to be chosen.

Love Making Preliminary.

Among the preliminaries of courtship the presentation by the male bird to the female of small fish is an elaborate and pretty ceremony. When laying commences, most birds are satisfied with one egg although two and very rarely three may be found. Incubation is shared by both sexes and lasts about three weeks. The egg shown in the cover picture is of average

shape and colour, but a great range of colour is to be found, from pale blue without spots to very dark brown with heavy blotches. Hardly any two specimens are exactly alike.

There is a similar variation in the colour of the chicks which are clothed in soft down, sometimes buff or fawn or grey with mottled and spotted pattern about the head. These young birds are alert and active and always ready to receive the lish brought in by their parents and to swallow them with lightning rapidity. They grow rapidly and become more and more daring in their excursions from the nest. Sometimes indeed they are washed off the island or sand bank altogether and only get back again by swimming strongly, encouraged by their excited parents. The plumage that succeeds the down is somewhat similar to that of the adult but differs in being spotted on the back.

Winter Spent at Sea?

These terns appear to spend the winter months at sea and enormous Hocks of them have regular resting places on off-shore islands or along deserted ocean beaches. When Spring comes again they return to their favourite nesting places, although it has been noticed that they rarely return to exactly the same site in two succeeding years. It appears that they do, however, return to an original site in alternate years and it may be that this habit ensures that the site is perfectly clean and free from vermin after being deserted for so long.

The extreme abundance of this species and the habit noticed in recent years of colonies choosing a nesting site quite close to busy beaches and public thoroughfares, should recommend them to our interest and protection.

Our cover picture is a faithful reproduction of the first of a series of sea bird pictures painted for us by Miss L. A. Daff, under the supervision of the authorities of the Auckland War Memorial Museum.