CHANGES IN WILD MAMMAL POPULATIONS IN CANTERBURY NEW ZEALAND FOREST SERVICE INFORMATION SERIES No. 52 CHANGES IN WILD MAMMAL POPULATIONS IN CANTERBURY by MAVIS M. DAVIDSON A. L. Poole, Director-General of Forests NEW ZEALAND FOREST SERVICE WELLINGTON 1965 NEW ZEALAND FOREST SERVICE INFORMATION SERIES No. 52 SYNOPSIS A review is given of the changes in wild tnammal populations in Canter­ bury, New Zealand, as determined from research into all relevant historical sources available to the writer and broi1;ght up to date (I962) from information supplied by the New Zealand Forest Service. The mammals concerned are: the native bats, rat, and dog, and the in­ troduced rats, rabbit, hare, cat, mustelids, hedgehog, opossum, wallaby, horse, pig, cattle beast, sheep, goat, thar, chamois, fallow deer, and red deer. Information has been given, as far as is known, of the date and place of liberation of the introduced mammals, the history of their establishment, and the present siti-1;ation and assessment of the future role of all wild mammals in Canterbury. Inset l All photos in this publication are copyright and may not be reproduced without permission. CONTENTS Page INTRODUCTION . 7 CHIROPTERANS.. 8 V espertilionidae Long-tailed bat (Chalinolobus tuberculatus) 8 Mystacinidae Short-tailed bat (Mystacina tuberculata tuberculata) 8 Southern short-tailed bat (new sub-sp.) (Mystacina tuber- citlata robusta) 9 RODENTS ro Heteromyidae Kiore rat (Rattus exulans) ro Norway rat (Rattus norvegicus) II Ship rat (Rattus rattus) II Mouse (Mus musculus) IZ Leporidae (Lagomorphs) Rabbit (Oryctolagus cuniculus) . r3 Hare (Lepus europaeus) 15, CARNIVORES r7 Canidae Wild dog (Ganis familiaris) 17 Felidae Wild cat (Felis catus) r9 Mustelidae Ferret (Putorius putorius) 20 Stoat (Mustela erminea) 20 Weasel (Mustela nivalis) 20 INSECTIVORE 22 Erinaceidae Hedgehog (Erinaceus europaeus) 22 MARSUPIALS 24 Phalangeridae Opossum (Trichosurus vulpecula) 24 Macropodidae Wallaby (Protemnodon rufogrisea) 28 5 Page UNGULATES (Perissodactyle) 30 Equidae Wild horse (Equus caballus) 30 UNGULATES (Artiodactyles) 30 Suidae Wild pig (Sus scrofa) 30 Bovidae Wild cattle (Bos taurus) 32 Wild sheep (Ovis' aries) 33 Wild goat (Capra hircus) 34 Thar (Hemitragus jemlahicus) 36 Chamois (Rupicapra rupicapra) 37 Cervidae Fallow deer (Dama dama) 39 Red deer (Cervus elaphus) 41 THE FUTURE 45 ACKNOWLEDGMENTS 47 LITERATURE CONSULTED 47 6 INTRODUCTION This paper was prepared for inclusion in the main symposium (The Changing Face of Canterbury) of the Royal Society of New Zealand's Tenth Science Congress, held in Christchurch in the year of the Canter­ bury centennial (1962). The requirement was for information on the history and present situation of the wild mammals in Canterbury together with an enlightened look into the future. The area under review is not that of the old Canterbury provincial boundary of 1876 (which reached northwards only to the Hurunui River), nor the Canterbury Land District (which finishes at the Conway River), but is that of the Canterbury Conservancy of the New Zealand Forest Service. This, flanked to the west by the Southern Alps, extends from the Waitaki River northwards to the Clarence River mouth beyond Kaikoura. The method of presentation of a paper on the wild mammals of Canter­ bury posed the problem of the order in which the animals should be described. It was thought that perhaps they should be separated into larger and small mammals, which would correspond roughly with those for which the New Zealand Forest Service is responsible (Davidson, 1958) and those controlled by other organisations. As usual the opossum posed a difficulty: it is a small mammal but until recently (31 March 1961) it was the responsibility of the New Zealand Forest Service, and still is so on Crown land. It is usual to separate the marsupials (Metatheria), the group con­ taining our opossums and wallabies, from the more common mammals (Eutheria); but, since there are no clear ecological differences between the two classes, both are considered here without differentiation (see Kean 1959a, 1961). 7 The deciding factor in the order of presentation was that surely one should refer first to our native bats, definitely small mammals. The unorthodox procedure was then adopted of fitting in the marsupials between the small and the larger mammals. We have then, chiropterans (bats), rodents (rats, mice, hares, and rabbits), carnivores (dogs, cats, stoats, weasels, and ferrets), an insectivore (hedgehog), then marsupials (opossums and wallabies), followed by the larger mammals, which, except for the horse (a perissodactyle), which is but briefly mentioned, are all artiodactyle ungulates (pigs, cattle, sheep, goats, thar, chamois, fallow deer, and red deer). Another matter calling for a decision was the use of the word "wild" where a more true description might be "feral" (usually applied to an animal which· has escaped from domestication and reverted to the wild state); it was decided that "wild" is commonly used by New Zealanders who are well aware of the situation and that "feral" could lead to con­ fusion. CHIROPTERANS (BATS) Hutton (1904) gives New Zealand only two native land mammals, the bats Chalinolobus (Peters, :i:866) morio (Gray), and Mystacops (Flower, 1891) tuberculatus Gray. See also Hutton, 1872. Dwyer (1960) refers to Chalinolobus (the long-tailed, short-eared, lobe­ 1 lipped, or wattled bat) as C. tuberculatus • Forster and identifies it as one of six species of the Australian genus Chalinolobus (family Vespertilioni­ dae); earlier, C. tuberculatus was confused with C. morio, a species from south-east Australia and Tasmania. The presence of a bat in New Zealand was recognised when Forster (1844), quoted by Dwyer, caught a long­ tailed specimen in Queen Charlotte Sound during Captain Cook's second voyage; but subsequently Gray confused this animal with the short-tailed bat (Buller, 1892). Dwyer (1960) calls the short-tailed, long-eared New Zealand bat Mystacina tuberculata Gray (sole species of the family Mystacinidae), and is inclined to agree with Dobson (1876) that it is "unique in being the most active climber of all bats"; it is confined to New Zealand. There have been unconfirmed suggestions of a third New Zealand species of bat (Polack, 1838, and Stock, 1876, quoted by Dwyer). From records, which he quotes, Dwyer (1962) has divided the distribution records of bats into those before and after 1930, and into (1) colonies or large flights and (2) small flights and isolated sightings. On this basis Dwyer has no records for Canterbury before 1930 other than in group (2), with four sightings of Chalinolobus and three where the species was unknown; most of these records were in Christchurch and vicinity. Hutton and Drummond (1923) note that the long-tailed bat was common in the Christchurch area until about 1885, roosting under the wooden bridges across the Avon (notably the Cashel Street bridge; E. G. Turbott (Canterbury Museum), pers. comm.), but that the replacement of these bridges caused the bats to disappear. Recently Turbott told me that there were unconfirmed reports that bats had been seen in Christchurch suburbs. An additional record 8 Photo: Domin.ion Muse·am Fig. I. Native bat (short tailed) furnished by Turbott is of a long-tailed bat found in October 1958 at Orari Gorge homestead, South Canterbury, by A. Graham, who took a colour photograph of the animal. Dwyer (1962) shows four Canterbury records after 1930, a recent record of a Mystacina, a Chalinolobus, and an unknown, virtually to­ gether in the Geraldine county of South Canterbury, an unidentified bat near the main divide in North Canterbury, but none in the Christchurch region. Senior Protection Forestry Ranger Lance Boyd (pers. comm.) advises that an unidentified bat was seen in the Lewis Pass area about 1956. Dwyer (1960) describes the bats as having the size of a mouse and states that they are bush dwellers, " usually seen only at twilight as they pursue insects over clearings or rivers and lakes. Fine summer and autumn evenings are favourable for observing these secretive animals". They hibernate in winter. Dwyer (1962) considers that the present distribution of bats is much less than it was a century ago, and he correlates the decrease with that of the area of forests; bats have failed "to survive in open country or to urbanise". Dwyer considers that there is no evidence of reduced density of bat population in unmodified forest, but there is some suggestion of predation from introduced mammals such as cats and black rats (Stead, 1937) and mustelids. Dwyer (1962) finds that there are two distinct forms of Mystacina which he has described as sub-species, a southern form which he has named 9 Mystacina tuberculata robusta, and the northern form (which probably includes those in Canterbury) which he calls Mystacina tuberculata tuberculata Gray. Dwyer's work suggests that the New Zealand bat population is static but that it may tend to rise coincidentally with the reforestation' which is taking place, and with tlie growth of new forests. As the diet of bats (Dwyer, 1962, p. 24) appears to be composed mostly of insects, introduced species of insects may well furnish an additional source of food, so that with restored and new habitat and a possibility of an additional food supply, a rise in the bat population may occur in the future. RODENTS RATS AND MICE Buller (1871) writes: "According to native tradition and the accounts of the early colonists, there formerly abounded in New Zealand a small frugivorous rat, which has, within the last quarter of a century, become almost extinct. The extermination of this apparently indigenous species is generally attributed to the introduced brown rat." (It has been the general opinion that the rats introduced by the white man displaced the native rat (kiore*); but Watson (1959) gives evidence for the coexistence of kiore and brown rat, and from information gained by R.H.