IN TOUCH WITH NATURE.

Otago Daily Times, Issue 15433, 20 April 1912, Page 2

IN TOUCH WITH NATURE.

NOTES ON NATURAL HISTORY IN

NEW ZEALAND.

(Br James Drummond, F.L.8.. F. 3.8.1

The origin and purpose of birds' migrations is attracting more attention as time passes, and it is probable that, with extensive and systematic work,Bamo definite' knowledge will be obtainable on this elusive but very fascinating subject. In New Zealand, native birds undertake strange migrations, it has been noted on many occasions that a species may be present in large numbers in a district one season, and after that it may absent itself for a decado. The most obvious theory is that tho birds, in these movements, are influenced by the conditions of the food supplies, flocking whero forest berriea are ripe and plentiful and deserting places where-the shrubs and trees have not fruited well.. Observations, howovor, have shown that tho theory is not quite satisfying. There is often in tltc birds' minds something besides a craving for the best food supplies. An illustration of this was afforded two years ago, when fantails were exceptionally plentiful in city and suburban gardens in Christchurch and although the flies and other insects upon which they feed were not unusually plentiful. Hundreds of fantails, apparently, deserted their haunts on the banks of streamlets and in forest glades to visit gardens in towns and cities, whero they had seldom been seen before. Outside the ranks of tho land birds, of course, there are the godwit, tho knot, and the sandpiper, which come to New' Zealand from distant lands, and the two cuckoos, which come as regularly as the Beasons.

Up to the present time inquiries into the movements of these birds have been mainly directed along the lines of speculation and-theory. Very few hard facta have been recorded, and a letter from Mr A. Landsborough Thomson, secretary of tho Aberdeen University Bird Migration Inquiry, suggests that fpmc steps of a more practical nature might, be taken in the Dominion. My Thomson is a son of Professor J. Arthur Thomson, Professor of Natural History at the Aberdeen University, and tho author of a largo number of notable scientific works, including "Outlines of Zoology," •" Evolution," "Heredity," and "The Biology of the Seasons." In his letter Mr Thomson says: " We should- be very glad indeed to see you and otliers who aro on the spot, and arc cognisant of the conditions, 'take up the bird-marking method adopted by our inquiry.' Anything wo can do'in tho way of advice we shall be only too glad to do.') From tho information supplied, I learn that tho object of

tho inquiry is to collect definite information by placing rings on tho feet of a lnrgo number of birds. It is hoped that if this is dono' Tcporta will be received of the subsequent movements of a proportion of tho marked birds. The rings aro placed on young birds found in (ho nests or on old birds Uiat can be caught without being injured. As the rings .are mado of aluminium, and are very light, they do not inconvenience the birds. Mos>, of the markin,-; is done in Scotland, and circulars have been widely distributed, requesting any person who captures, hills, or receives news of the marked birds to communicate with the natural history department of the university, sending particulars of the locality in which the bird was found, tho date, and the nnmbor on tho ring.

Mr Thomson 6tatos that different mothods of marking havo been suggested or tried. Amongst these aro parchment tied under tho tail with silk, thin metal discs glued to tlie Uiil-fcathore, and indeliblo stamps on the eame feathers. All these methods, howcver t aro clumsy, and arc useless as a moans of identification after the next moukt. Obvioualy for convenience and permanence, marks on tho feet aro best. In early attempts brass wire or dlk thread was twisted around a bird's foot, but an inecription of some kind is necessary, and >t has been found that nothing is better thin an aluminium ring, which is ligliit and durablo, and is easily stamped and worked. Information in regard to the capture of a marked bird depends upon the address stamped on the ring. Some rings bear only tho markor's initials, but th:s method is un-

satisfactory on account of tho difficulty tho person who captures the bird may experience in finding the headquarters of tho inquiry movement, and) it almost completely prevents records '"being rotanicd from a great dislojx». Many oirds havo 'been found with rings bearing insufficient addresses, but news of their discovery ban not been sent to tho marker because ho could not bo found. In tho Bret system- ' atic scheme attempted, young -woodcock on the Duko of Northumberland's estate at Alnwick, Northumberland, bora rings with tho letter " N " and figures representing tho year. A mare elaborate method of marking was adopted by the American Bird Banding Association, whoso rings havo an identification number and the words " Notify ' The Auk,'- New York." In the movement with which • Professor Thomson and Mr -Thomson aro associated tho words " Aberdeen University " and a number are placed on each ring but on tho smaller sizes, used for small birds the words are conk-acted to " Aberdeen Univ." In ringing tho birds tho Inquiry has , tho hobY of a largo number of ladios and gentlemen who have volunteered their services. Mc«t of .them livo in Scotland but scone aro in England, Wales, mid Ireland. A fow m-Btematically nndortako bird-catching in the winter months, relying chiefly on clap-nets, automatic cagetraps, and other harmless appliances. Many birds, notably gulls on \m shore, . have been caught at night by means of acetylene cycle lamps, which dazzle and bewilder them. Each co-operator ia sup-1 plied with a hst of tho common species j for which the sizes of rings may be used, i With tho rings the Inquiry sends schedules, on which particulars of marked birds are' ►ocorded. When the eohodnlee ore returned to tho Inquiry, tho particulars .they contain aro copied into a largo ledger. In the present stage of tho work no attempt is mado to form conclusions. Amongst tho results obtained may be mentioned a widgeon, duckling, marked on Loch Brora, Scotland, on June 19, 1909, and caught in a duck decoy in Giovingen, north-eastern Holland, on September 3 in the 6amo year. A number of young' fop. wings wore marked on tho north-east of Scotland in tho summer of 1910. .Four were caught in Ireland at tho end of 1010 or tho beginning of 1911;■ and ono was caught at Oporto, Portage!! A-song thrush, marked in a nest at. Aberdeenshire on June 4, 1910, was shot at Leira, Portugal, on November 6 in tho same year. A starlinc, marked nt Edinburgh on March 20, 1911, was found at .Saltdalcn, Norway, just above tho Arctic

Cirolo, on April 20, 1911. In Now Zealand there is an objection to interfering with Uio rare tialivo birds, bnt tharo bc«iiis to be no reason why, later on, an

attempt should not bo mado (o obtan iffformation in this way in regard to the movemonts of species that aro not protcctcd.