IN TOUCH WITH NATURE

Otago Daily Times, Issue 18768, 23 January 1923, Page 2

IN TOUCH WITH NATURE

A DRAGON-FLY PROBLEM. By J. Drummond, F.L.S., F.Z.S. New Zealand's largest dragon-fly, a handsome and conspscu-j.-a yellow-banded insect, is in evidence at- this time in some swampy places. It is almost three inches long from the top of its head to the tip of its body, and its forowings, slightly iridescent, have a spread of about lour inches and a-half. bbl rolling tussocky downs it darts with surprising rapidity through (ho air, often only a few feet from the ground, in search of flies and other insects it lives on. The males, distinguished by two rounded leafbke appendages at the ends of their bodies, are less retiring than the iemales. This or, perhaps, actual numbers, accounts for tlie (act that six males may be counted lo one lemale. the brown grub, about two inches and a-half long, is ugly, iiorce, and agglessive, and snaps at lingers that handle it, although the perfect insect, however formidable 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 (he Cawthron Institute, Nelson, collected Uropetala dragon-flies, Later he caught individuals at Arthur’s Pass. He noted that in tho black and yellow colour pattern on the head the dragon-flies from both the places differ from individuals of Uropetala carovei, caught 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 bo handled safely. They were in holes about half an inch in diameter in peaty soil. By inserting his fingers into a hole and wonting his hand down, enlarging the hole at the same time, until a depth of from ton inches to one foot was reached, he could feel tho grub at the bottom and pull it out. Lpecinions of the Cass and Arthur’s Pass dragonflies 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 tho Cass and Arthur’s rass dragon-flies are very distinct from Uropetala. carovei in those collections. It is not quite certain whether the differences make tno Cass and Arthur’s Pass dragon-flies a distinct species, or rank them merely as a sub-species or a geographical race, but the differences are so well marked and so constant over the whole series of individuals examined, that Ur Tillyard has established a new species, which he has dedicated to Ur 0. Chilton, Rector of Canterbury College, as a memorial lo the rector’s excellent work in connection with tho Cass Observatory.

As far as is known at present, Uropetala carovei occurs over the whole of the North Eland and in the Lake Wnkatipu district, and Uropetala Ghiltoni occurs only at, Cass and Artluir’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. Ur liltyard asks that specimens of Uropetala should be sent to him, with the places in which they are caught named. Ho suggests that Uropetala Ghiltoni 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,” ho adds, “1 mated two canaries, and I have been impressed by the code of signals the young ones seem to understand.- Tho 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 tho brood. They seem to take definite instructions from tho parents. Whenever anything is put into the cage for the first time, like a cherry or grass of 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 lit 110 note, and the family start in to sample the food.

"The fat her seems to do the feeding when the young ones are in the nest, and so Jong as (ho coast is clear the mother twitters up and down the cage; but as souu as anyone approaches she stops still, and the father stops feeding at the same instant. It all seems to be a mutter of signals. It was very pretty to see how the first brood ran to their mother even after they were fully Hedged. While she was sitting on a second lot of eggs, the other four often sat all round the nest, or in it, to keep her company, and sometimes they walked nil over her, or fluffed up and wont to sleep, on the edge. The male does not sing during the breeding season except for one or two little trills very early-just after daybrenk—and these outbursts seem to coincide with tho hatching of the (hicks. Otherwise, he gives signs of the very gravest responsibility, and seems worried for the most part.

“It is very amusing to see the young birds having a siesta at odd hours of the clay. They fluff up and put their heads under their wings and go to sleep in broad daylight. Sometimes they all have a nap at the same time, but sometimes one who is more wakeful than the others and pulls the others’ tails and wakes them up. -is mischievously us a monkey. 'I he young birds are very fond of a bath, and they like a crystal dish best.’’

"It is surprising how soon most flowers fade," Mr 11. Hill, an able and experienced botanist, writes from Napier. "Pohutukawa trees that uere 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 tho plant from which the flowers sprang. It is so with all flowers, with all life, for living, and dying represent tho organic world in the great round of change. One might write much of tho brotherhood of trees that arc 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 tho 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 Hue of Norfolk pines, for their natni- home is an island in tho Pacific Ocean, and for many years their ancestors were subject to sea spray, and after a time they became immune from injury when tierce storms blew over them from the ocean, 't he fame thing takes place in (he case of the pohutukawa, tho karnmu, and other trees and shrubs along tho seafront here ; they have learnt the art of adapting themselves to boisterous winds and salt spray.”