IN TOUCH WITH NATURE

Otago Witness, Issue 3594, 30 January 1923, Page 6

IN TOUCH WITH NATURE

A DRAGON-FLY PROBLEM.

By

J. Drummond, F.L.S., F.Z.S.

New Zealand’s largest dragon-fly, a hand- ! foine and conspicuous yellow-banded insect, t-M in evidence at this time in some swampy places. It is almost three inches long from the ton of its head to the tip of its body, l and its forewings, slightly iridescent, have C • spread of about four inches and a-half. f rolling tussocky downs it darts with i aurprising rapidity through the air, often t’rtnly a few feet from the ground, in search 3®f flies and other insects it lives on. The jinales, distinguished by two rounded leafijike appendages at the ends of their bodies, i*re less retiring than the females. This ® r , perhaps, actual numbers, accounts for f the fact that six males may be counted to , one female. The brown grub, about two i Inches and a-half long, is ugly, fierce, and 1 Aggressive, and snaps at fingers that handle j it, although the perfect insect, however fort Dutiable it may be to small insects, is Utterly harmless to human beings. As it does not seem to have a popular name, its official title, Uropetala carovei, is unavoidable. When spending a few days at the Biological Observatory in the Cass Valley, .Southern Alps, Dr R. J. Tillyard, of the jpawthron Institute, Nelson, collected Uropetala dragon-flies. Rater he caught indi- ! .Viduals at Arthur’s Pass. He noted that in 4he black and yellow colour pattern on the , head the dragon-flies from both the places differ from individuals of Uropetala carovei, flftught in other parts of New Zealand,

Grubs he found in a small mountain swamp at Cass, unlike the grubs of Uropetala carovei, were inert and could be handled safely. They were in holes about half an inch in diameter in peaty soil. By inserting his fingers into a hole and working his hand down, enlarging the hole at the same time, until a depth of from ten inches ' to one foot was reached, he could feel the grub at the bottom and pull it out. Specimens of the Cass and Arthur’s Pass dragon- . flies were taken to England and Europe, and were compared carefully with specimens of Uropetala carovei in dragon-fly collections in the British Museum and the Brussels Museum. The comparison established the fact that the Cass and Arthur’s Pass dragon-flies are very distinct from Uropetala carovei in those collections. It is not quite certain whether the differences make the Cass and Arthur’s Pass dragon-flies a distinct species, or rank them merely as a sub-specUs or a geographical race, but the differences are so well marked and so constant over the whole series of individuals examined, that Dr Tillyard has established a new species, which he has dedicated to Dr C. Chilton, Rector of Canterbury College, as a memorial to the rector’s excellent work in connection with the Oass Observatory. As far as is known at present, Uropetala carovei occurs over the whole of the North Island and in the Lake Wakatipu district, and Uropetala Chiltoni occurs only at Cass and Arthur’s Pass, but the distribution of the two species, if they are distinct species, is by no means determined. One of them, probably Uropetala carovei, is common on the lonely Gouland Downs, extensive sanctuaries between Collingwood and Westport. Dr Tillyard asks that specimens of Uropetala be sent to him. with the places S, ..4. J rd

in which they are caught named. He suggests that Uropetala Chiltoni may be the species that inhabits the West Coast of the South Island, and that it may be encroaching on the domain of uropetala carovei through the gap at Arthur’s Pass. In any case, he believes that each island does not possess its own peculiar species of Uropetala and that some barrier other than Cook Strait has brought about the differences in the forms. “Is there any ground for supposing that birds have anything in the nature of a. language, apart from the ordinary signals for danger?” a Christchurch correspondent asks. “This year,” he adds, “I mated two canaries, and I have been impressed by the code of signals the young ones seem to understand. The birds have a very keen instinct of when they are watched, or when anyone is going to watch them, and the male always hops down on the floor under the nest whenever anyone approaches. There are four young birds in the brood. They seem to take definite instructions from the parents. Whenever anything is put into the cage for the first time, like a cherry or grass or lettuce, or even a piece of sugar, the birds all stand stock still while the old bird makes up his mind whether it is good or not. Then he gives one little note, and the family start in to sample the food. “The father seems to do the feeding when the young ones are in the nest, and so long as the coast is clear the mother twitters up and down the cage; but as soon as anyone approaches she stops still, and the father stops feeding at the same instant. It all seems to be a matter of signals. It was very pretty to see how the first brood ran to their mother even after they were fully fledged. While she was sitting on a second lot of eggs, tho other four often sat all

round the nest, or in it, to keep her company, and sometimes they walked all over her, or fluffed up and went to sleep on the edge. The male does not sing during the breeding season except for one or two little trills very early—just a'fter daybreak—and these outbursts seem to coincide with the hatching of the chicks. Otherwise, he gives signs of the very gravest responsibility, and seems worried for the most part. ‘‘lt is very amusing to see the young birds having a siesta at odd hours of the day. They fluff up' and put their heads under their wings and go to sleep in broad daylight. Sometimes they all have a nap at tlie same time, but sometimes one who is more wakeful than the others and pulls the others’ tails and wakes them up. -.s mischievously as a monkey. The young birds are very fond of a bath, and they like a crystal dish best.” “It is surprising how soon most flowers fade,” Mr H. Hill, an able and experienced botanist, writes from Napier. “Pohutukawa trees that were ablaze in the crimson and scarlet-reds in the middle of December had passed on by January 1. They had fulfilled their mission, namely, to prepare for new births and illustrate the sureness of death of the plant from which the flowers sprang. It is so with all flowers, with all life, for living, and dying represent the organic world in the great round of change. One might write much of the brotherhood of trees that are known ae pohutukawa, manuka, rata, blue gums and so on. They all belong to the myrtle family and have family likenesses in their flowers that hardly can be mistaken. A range of trees on the sea side of the Marine Parade in Napier, perhaps, is unequalled elsewhere in New Zealand. The sea spray, dangerous as

it is to most garden trees and shrubs, has no effect on a line of Norfolk pines, for their nativj home is an island in the Pacific Ocean, and for many years their ancestors were subject to sea spray, and after a time they became immune from injury when fierce storms blew over them from tho ocean. Tho same thing takes place in the case of the pohutukawa, the karanni, and other trees and shrubs along the seafront here; they have learnt the art of adapting themselves to boisterous winds and salt spray.”