No. 102 JULY 1990 REGISTERED BY AUSTRALIA POST PUBUCATION No. TBH0495 ISSN 0819-6826 POSTAL ADDRESS: G.P.O. BOX 68A, HOBART 7001 ANNUAL SUBSCRIPTION: $10.00 EDITOR: D.G. HIRD THE HABITAT AND CONSERVATION STATUS OF THE TASMANIAN BETTONG by Michael Driessen and Gregory Hocking Department of Parks, Wildlife and Heritage INTRODUCTION The Tasmanian bettong (Bettongia gaimardi) is one of three species of bettong found in Australia. All three species had wide distributions on the Australian mainland at the time of European settlement; all have since undergone a massive reduction in range and are now restricted to a number of remnant populations. The Tasmanian bettong once ranged beyond Tasmania from south-eastern Queensland through New South Wales, Victoria and into south eastern South Australia, but it has not been recorded on mainland Australia for over 60 years. The cause of this dramatic reduction in range has been attributed to a combina¬ tion of habitat clearance for agriculture, modification of habitat by stock, and the impact of various introduced animals such as the feral cat, the rabbit and in particular the fox. This report summarizes a recently completed study carried out by Michael Driessen and Greg Hocking of the Tasmanian Department of Parks, Wildlife and Heritage which assessed the habitat associations, conservation status and management requirements of the Tasmanian bettong. DISTRIBUTION AND HABITAT OF THE BETTONG The range of the Tasmanian bettong extends throughout the drier parts of eastern and central Tasmania (see Figure 1). It occurs as far west as the Mersey River in the north, Derwent Bridge in the Central Highlands and National Park, Judbury and Geeveston in the south. Within this range, highland areas above 1,000m and the higher rainfall areas of the north east are excluded. Each author is responsible for the opinions and facts expressed in his or her article— EDITOR. 2 The T asmanian Naturalist julv i 990 Throughout its range the bettong occurs in a number of different dry sclerophyll communities. In all 14 dry sclerophyll communities were identified. For convenience these can be categorised into the following broad groups: Lowland Grassy Forests and Woodlands Lowland Heathy Forests Highland Grassy Forests and Woodlands All communities were typified by an open understorey. Bettongs were largely unrecorded from sedgey and shrubby dry sclerophyll forests which typically have a dense understorey. In addition bettongs were rarely recorded from grassy E. delegatensis forests. It is estimated that the total area of potential bettong habitat in Tasmania is in excess of 1,000,000 ha or approximately 15% of Tasmania. However, within this large area bettongs generally occur at low densities, something in the order of 1 bettong for every 17 hectares of habitat. Very limited areas support high bettong densities. These areas include heathy Casuarina littoralis forests in the north and north east of Tasmania, grassy Eucalyptus rodwayi woodlands in the Central highlands, and grassy E. amygdalina woodlands on lateritic soils in the Midlands. Bettong densities were also high where suitable habitat occurred on soils derived from the Mathinna beds and granite in the north east of the State. Suitable habitat on soils derived from Jurassic dolerite supported particlarly low densities. Grassy E. dalrympleana forests in the Central highlands also support particularly low densities. IMPACT OF LAND MANAGEMENT PRACTICES Most of the bettong range occurs on either private land or State Forest and is therefore vulnerable to various land management practices. Clearing for pasture: In the long term, conversion of forest to pasture represents the most serious threat to bettong conservation. The area of improved pasture has increased by approximately 35% to over 800,000 ha in the past 25 years and much of this area has been at the expense of bettong habitat. 1080 Poison: Bettongs are highly susceptible to 1080 poison and evidence suggests that its repeated use leads to a reduction in bettong numbers particularly in small or isolated populations. The use of 1080 poison is widespread in Tasmania, and the number of poisoning operations has increased dramatically in recent years. The Tasmanian Naturalist july 1990 3 V \ Illustration by T. Woolcott Courtesy of Australian National Parks and Wildlife Service Grazing: Evidence suggests that heavy grazing is associated with a reduction in bettong densities. It is not known whether this is due to the compacting effect of stock on soil and underground fungi (upon which bettongs mainly feed) or to the use of fertilisers which increases the soil fertility and may lead to a reduction in the abundance of underground fungi and hence a reduction in bettong densities. Fur¬ ther investigation is warranted in this area. Forestry Practices: Current logging practices in general represent a minimal threat to bettong conservation. The selective removal of up to 75 % of tree stems does not appear to be detrimental to bettongs provided that the essential structure of the vegetation is retained. In the long term clear felling followed by regeneration does not ap¬ pear to be detrimental to bettongs provided suitable habitat is left adjacent to the cleared area. Areas supporting older regrowth forest were more suitable for bet¬ tongs than younger regrowth forest. The extent of pine and eucalypt plantations within the bettong range is relatively small although increasing steadily. Although bettongs are known to utilise eucalypt and in particular pine plantations it is not known whether they can live in plantations in the absence of any suitable native vegetation. Further investigation is required in this area. 4 The Tasmanian Naturalist july 1990 Mining: The extent of mining within the bettong range is very limited, however gravel quarrying represents a threat to those bettong populations on lateritic soils. Fire: Fire is a common occurrence within the range of the bettong and appears to play an integral part in maintaining bettong habitat to create an open understorey. Fire is also believed to promote the fruiting of mycorrhizal fungi which form the bulk of the diet of bettong. Reservation of Habitat: Bettong habitat is poorly reserved in Tasmania. Most reserves contain less than 400 ha of dry sclerophyll forest. Although all reserves are of some use for bettong conservation, ultimately their conservation may rely on appropriately managed reserves of larger size. It was estimated that a minimum of 3,300 ha of suitable bettong habitat is required to maintain viable populations of bettongs. Three reserves appear to meet this requirement, they are Mt William, Freycinet and Douglas Apsley National Parks. Maria Island National Park may be suitable with appropriate fire management. Foxes: There is a growing amount of evidence implicating the fox as one of the most, if not the most, important factor contributing to the decline and extinction of small and medium sized mammals on the Australian mainland. Whilst foxes do not occur in Tasmania, every effort must be taken to prevent the establishment of this species in the State. CONSERVATION STATUS OF THE BETTONG Statewide, the conservation status of the Tasmanian bettong was considered to be potentially vulnerable which means that although the species has a wide distribution and is apparently moderately abundant, it requires monitoring and protection to prevent a decline in status. On a regional level the conservation status of the bettong in the northern Midlands is considered to be vulnerable. If current land management practices continue then the bettong is likely to become endangered in this region in the foreseeable future. The Tasmanian Naturalist july 1990 5 Figure 1: Distribution of bettong sites 6 The Tasmanian Naturalist july 1990 MANAGEMENT RECOMMENDATIONS The report makes a number of recommendations for the future management of the Tasmanian bettong. These include: • The creation of additional reserves in areas of dry sclerophyll forest, particularly in the northern Midlands. • Regular monitoring of bettong abundance. • Limiting use of 1080 poison in areas containing isolated bettong populations. • Consideration of the use of fire as a management tool to maintain bettong habitat in reserves. • Publicity to increase the public’s awareness of the bettong and its requirements. FURTHER READING Driessen, M.M, Hocking, G.J. & Beukers, P. (1990) Habitat, Conservation Status and Management of the Tasmanian Bettong (Bettongia gaitnardi). Report of the Tasmanian Department of Parks, Wildlife and Heritage. TheTasmanian Naturalist julyi990 7 BOOK REVIEW Australian Cicadas by M.S. Moulds University of New South Wales Press, 217 pp. R.R.P. $39.95 Reviewed by P.B. McQuillan Singing cicadas are as evocative of an Australian summer as sun cream, but until now it has been difficult to find reliable information about them. Max Moulds, our leading authority on cicadas, has finally filled that need with a handsome and comprehensive book which distils decades of endeavour. All 200-plus described species are mentioned in this book, most with detailed notes and a map on distribution, habitat, distinguishing features and where known, life-history and song. The seven Tasmanian species are well covered. The low diversity of our fauna is offset by its novelty, including the elusive nocturnal hairy cicada, which is unable to sing, and three species of Diemeniana which are conspicuous denizens of alpine heathlands and buttongrass plains in the west and south. Part 1 of the book is given over to 9 chapters which, among other things, cover the principles of classification and history of vernacular names, details of how cicadas produce and receive sounds, and a useful account of procedures to follow for setting up a cicada collection. A key to assist identification is not provided but the 24 colour plates are an excellent visual reference which, together with the sup¬ porting text in Part 2, guide the reader to the appropriate name for their specimen. A glossary, extensive reference list and index complete the book. A lasting impression is that much detail on the behaviour and biology of many species remains unknown and here is a fertile field for patient endeavour. I have no hesitation in recommending this book to all naturalists. ' . -tJ J2 -3 (n 4J o CA 'Tasmanian ‘fieCcC9^cLturaCists' Ctub ( ( TT < H0 ******* BULLETIN NO. 259 SUPPLEMENT TO THE "TASMANIAN NATURALIST" July 1990 The Tasmanian Field Naturalists Club is devoted to the study of all forms of Natural History, and is comprised of both experts and beginners. We cover a wide variety of topics, and we support conservation. Meetings are held on the first Thursday of every month, except January, in the CSIRO Conference Room, Stowell Ave, Battery Point, at 7.45 p.m. Outings are usually held the following weekend, meeting outside the new entrance to the Museum, Macquarie Street. The Club's address is G.P.O. Box 68A, Hobart, 7001 and the Secretary is Ms Helen Davidson, phone 23 7015. **************************** *"* *************************************************** PROGRAMME 7.45p.m . Don Hird will give an overview of Tasmania's small mammal fauna, in particular those to be found on Mt. Wellington. 8.00a.m. (from Museum) Mote early start ! We will visit Mt. Wellington to inspect tn results of Don's live-trapping of these native mammals. (If the weather is very bad, the trapping will be on Porter's Hill, Lower sandy Bay, not the mountain.) 7.45p.m. Members Night . Would all members who have natural history slides and meme.rcos of their recent holidays or outings, and would like to contribute to the evening, please contact Helen as soon as possibLe so that a programme can be arranged. Federation of F.N.C. we=kend at Banksia Camp, Port Sorell, hosted by the Devonport Field Mats. Club. If you would like to attend,- please contact Helen for copies of the itinery, etc. 9.00a.m. Note: 3rd. Sat, in Sept.! A special springtime visit to Capricorn 1, an educational farm and children's holiday resort near Cygnet. We will be joined by special guests who will assist us in an initial assessment of the streamside area's natural history, prior to the establishment of a Nature Trail there. (See the item later in this Bulletin for further details.) 7.45p.m. Mr. Malcolm Walls, an expert in underwater photography, will show us some of hi5 beautiful slides of Tas. marine life. You will view fish you have never seen or possibly even heard of before! 9.00a.m . Dr. Robert TayLor will lead us and members of B.O.A.T. on an outing via the Nugent Forestry Road to the Sandspit River Forest Reserve, the WieLangta Forest Block with its tall trees and the Three Thumbs near Orford which has interesting plants and bird-life and where, from the Lookout, we will be able to obtain wonderful coastal views. We will visit a gully of remnant rainforest as well as wet sclerophyll and dry sclerophyll areas. 7.45p.m. Peg Putt, the Nature Guarantee Coordinator with the Tasmanian Conservation Trust will give an illustrated talk on Protection for Tasmania's Endangered Species and their Habitats. A trip to Bruny Island with Peg Putt and Sandy Tiffin to visit the Trust's newly acquired Lutregala Marsh Reserve. ******************************************x***************************************** NEW MEMBERS: Patti Virtue and her son Jacob of the Glebe, Glenda Johnson of Rosny and Georgina Docharty of Bellerive have recently become members to TFNC. We welcome them all and hope they will continue to enjoy attending our meetings and outings. ******************************************,***************************************** VISIT OF AMERICAN NATURALISTS : On Wednesday October 31st and Thursday November 1st, a group of 20 North American ladies will be visiting Hobart. Len Wall, Helen Davidson and Robbie Poynter will act as guides for their trips to various natural history sites in Southern Tasmania. It is hoped that they will confclude their stay by attending Peg Putt's talk on Thursday night and meeting some more of our members. ****************************************** 1 ****************************************** Thurs. Aug. 2nd. Sat. Aug. 4th. Thurs. Sept.6th. Sept.7th,,8th. and 9th. Sat. Sept. 15th. Thurs. Oct. 4th. Sat. Oct. 6th Thurs. Nov. 1st. Sat. Nov. 3rd. SGAP WILDFLOWERS OF AUSTRALIA EXHIBITION: The show will be held at the City Hal' Hobart from 12th-15th October. The committee and other members are busily involved in organising our display which will be entitled "Collecting With Care". It is envisaged that plants, insects, snails, shells, mammal scats and skulls, seaweeds and reptiles will be collected, preserved and exhibited. We require volunteers to help set up the display on Thursday October 11th, staff it and give out information to the public during the exhibition which will be open daily between 10 a.m. and 8 p.m., and to assist in dismantling the display after 3 p.m. on Monday 15th. Please let Sue Collier know (ph. 29 6597) when you will be available so that a roster can be drawn up. This will be a great opportunity for you to publicize our club, meet many interesting people and take a prolonged look at the other displays. x *********** A-***********************************************************************:.'- CAPRICORN 1 OUTING: The farm is situated between Cradoc and Glaziers Bay, opposite the southern end of Egg Island. We will be observing and hopefully identifying some of the native plants, birds and invertebrates, as well as the fossils on the property. It is envisaged that an educational leaflet will be produced to indicate to children the significant flora and fauna along the Nature Trail route, and to encourage them to study them further. Children will be very welcome to attend on Sat. 15th, but parents are asked to please supervise them at all times as there will be a lot of newborn farm animals there then and the owner would like them not to be disturbed or harmed in any way. ************************************************************************************* TFNC INC.? In conjunction with the review of club rules, the committee is invest¬ igating Public Liability Insurance and whether or not the club should become incorporated. Recommendations will be put to members at a special general meeting once sufficient information is available. ********************* **************************************************************** NEW MEETING VENUE AND LIBRARY LOCATION : After inspecting several buildings, committee members have decided to accept the offer of accommodation in the Life Sciences building at the University. Meetings will be conducted in a seminar room and the Library will be stored upstairs in a laboratory. It is envisaged that the November meeting will be the first held at this new venue and the Library will be moved around about this time. Further details and directions will be given in the next Bulletin. ********************************^***************************************************** COATES Wildlife TOURS OUTBACK CAMPING SAFARIS NEW 1990 BROCHURE AVAILABLE NOW Including our popular range of wildlife tours in and Introducing two new tours Western and South Australia and the Northern . 25 day New Zealand Botanical Tour Territory - 7 day Christmas Island Nature Tour For further informcrtion and brochures, please contact: 87 First Avenue, Mount Lawley, Western Australia 6050 Tel: (09) 271 7879 Fax: (09) 271 5570 V. Uc. No 9TA00358