MUSEUM OF NATURE Kerguelen petrel- rare visitor

Press, Volume CXV, Issue 33739, 11 January 1975, Page 11

MUSEUM OF NATURE Kerguelen petrel- rare visitor

An exciting recent addition to zoological collections at the Canterbury Museum was a well preserved specimen of a small species of ocean-living bird—the Kerguelen petrel.

This is the first specie men of this little-known petrel the museum has received — which is remarkable in view of the countless thousands of birds which have been brought to us for identification over the years. The Kerguelen petrel is about the same size as a domestic pigeon. Although of drab appearance, with feathers of a uniform grey-brown, this petrel has an impressive

33in wing-span. It frequents the <subAntarctic, South Atlantic and South Indian oceans but occasionally stormdriven birds are wrecked on the western coastlines of Australia and New Zealand. Of the 20 New Zealand records of this petrel most are of dead snecimens which have been washed up the west coast of the North Island. Nesting colonies The history of our newly acquired specimen is consistent with the details of those previously reported — it was found exhausted on October this year near Greymouth. Although cared for by the attendants at the Wildlife Game

Park at Paroa it died a day after it was found. The bird was subsequently forwarded to us by the branch office at Greymouth. Little is known of-the biology of the Kerguelen petrel. Nesting colonies of this nondescript oceanic wanderer have been discovered on Kerguelen and Marion islands and on Tristan da Cunha and Gough islands. Eggs are laid in October and November of the southern summer in a leaf-lined nest bowl built in a chamber at the end of a tunnel. As is typical of many of its relatives the Kerguelen petrel lays a single white egg. Chicks have been observed in December and in the few nesting colonies studied adults and juveniles have already vacated these by February. Identification The Kerguelen petrel belongs to the Procellariiformes a grouping of birds which includes the albatrosses, mutton birds and other petrels. Many of these, particularly the smaller species, are extremely difficult to distinguish in the open. Indeed the normal lot even of those who specialise in oceanic birds is to return from a sea voyage with a longer list of tentative identification than positive ones. ’ A tip for distinguishing shearwaters and petrels from other coastal and oceanic birds is to note their mode of flight. The smaller Procellariiformes have a rapid gliding flight — they skim low over the waves and wheel in broad arcs. The larger representatives, for example the albatrosses and mollymawks glide more and flap less. On the other hand the storm petrels fly very close to the surface of the sea and their flight is more erratic. Most shearwaters and petrels are similar in shape and colouration. Invariably they are white, black or a combination of these. In many instances it is the pale markings which are diagnostic. Field book It is essential that oceanic birds are observed at close quarters in good conditions before positive identifications are made. One complication is that the paler markings are usualy concealed when a bird lands or settles on the water.

Many species can only be identified in flight. Perhaps the simplest way of becoming familiar with oceanic birds is to stroll along a beach after a storm in search of beach-wrecked specimens. Basic requirements are a good field book for identification, some scales, and a ruler or slide cali-

per for taking measurements. As a double checlj some beach-combers might collect their specimens in plastic bags and compare them with the comprehensive collection of Procellariiformes we have on display at the museum, or consult the museum zoologist. — G.A.T,