Unsurpa�s�d accuracy Finding your way in the and prec1s1on bush with SILVA I11Iustrated 1s SILVA type 41 Map magnifying fens Finest Swedish Map and compass use opens up the real steel needle enjoyment and many rewards of finding Pivot on friction- your way 1n the bush with full free sapphire confidence. The Swedish SILVA designers have made the tedious task of compass work a pure simplicity. When you add a SILVA -0.' · Distortion proof compass to a topographic map and a acrylic baseplate few basic map reading instructions, you gain a sixth sense. The sense of "seeing" Non-radioactive over the hill: knowing what to expect luminous readout behind it and how to get there with the Anti-static, liquid least effort. Most importantly, it will filled capsule enable you to get back to your home base, as well as find that special spot As syea as 1,2,3 to use again next time. 1 Place compass on map Fun & safety in the bush with edge along direction of travel Good compass and map use increases SILVA compasses are built to the highest the fun and safety of outings in the standards of accuracy, not deliberately 2 Rotate the bush. capsule until "N" on compass dial points With a good map and a SILVA Compass, down to a low price. SILVA is the only north on map a sense of complete independence and North-South lines freedom of movement 1s acquired. Any compass in the world that uses the finest should be parallel Swedish steel in its sensitive magnetic wuh magnetic time that you feel like leaving a track or North gnd lines on road, you will be able to take a direct the map needle. SILVA is filled with a unique non­ route through the bush knowing the yellowing anti-static liquid that resists bubble 3 Hold compass direction and distance required to travel. honzontally In front A standard SILVA compass is not formation. SILVA is tested to operate in of you and rotate your body until red expensive, retailing for around $30. temperatures from -40C to +SOC. SILVA is point of needle ,s Some more professional models cost a over red part of little more. And there are more than 60 North arrow. Look specially counter- balanced to account for up. pick up a land different models in the SILVA range. mark and walk the magnetic dip forces found in Australasia. toward it The SILVA Guarantee When its a SILVA compass you can be sure SILVA guarantee that their compasses are there is no better or more accurate compass unsurpassed 1n quality and accuracy, being shockproof, waterproof and come you can buy. with an exclusive 6 year warranty Choose from many differentSILVA models at backed by an Australian better camping stores throughout Australia, after sales and spare parts service base. but beware of cheaper, look-alike imitations. There is no other compas that 1s more accurate Look for this display than SILVA. in all good camping stores that sell quality equipment You'll find a compass displayed to suit your exact requirements and Insist on budget. Try them for yourself and quality test the "Easy as 1,2,3"" SILVA system. asl< for a SILVA Compass! Trade enquiries: Macson Trading Company Ply Ltd Tel (03) 9489 9766 Fax (03) 9481 5368 http://www.macson.com.au - u Front 30 JUN 1999 coral cay in the Great Barrier Reef, we follow the trials and tribulations of booby chicks struggling to reach maturity. now all about the From the moment they hatch, these Effect? ick of Greenhouse birds are harassed by siblings, ino? Well here's hearing about EI neighbours and predators, and if that's you not a global phenomenon may not enough, their parents are often be as familiar with but one that can conned out of dinner before it gets to have just as much impact on the them. planet . and us. In fact it's Velvet geckos, on the other hand, responsible for Australia turning face quite different dilemmas. Being from the lush tropical forest of th nocturnal, they laze about in the warmth past into the harsh desert we know of their rock crevices during the day and today. It's called an ice age and it then rush about at night until it's time to seems that our planet has been go home. Unfortunately for Lesueur's 5 subjected Lo several of these cold Velvet Gecko finding a home is a bit like � Lesueur's Velvet Gecko. events since they began millions of playing Russian roulette as any potential r years ago. Wl1at started all this f eezing and thawing is still abode could contain an angry rival male or even a gecko­ unknown (although Geoff McNamara presents some eating snake. So how do the geckos tell which home is a safe intere ting theories) but what continues to trigger them house? appears to be a complicated interplay of various planetary We also take a look at how giant squids have sex, and conditions. One thing is for sure, they have been responsible discover that the smartest marsupials are wearing long tails. for some major events including mass extinctions and Our regular features include tips on saving a species when allowing humans to migrate from Siberia Lo Alaska. So when there is only one individual left, instructions on the best way is the next one? Is it time to stock up on extra winter woollies? to serve earthworms to your friends, advice on how to beat You may be surprised by the answer. Read 'The Big chill" on the flim-flam virus, and The Last Word highlights what can page 54 and find out. happen when we all look the other way. From the chill of an ice age to the tropical warmth of a -Jennifer Saunders Sorry We don't have any of the things you may be used to. But we do have clean air, fine food and enchanting scenery Talk to your NO TRAFFIC JAMS, travel agent about a visit to Freycinet Lodge, and immerse yourself POLITICIANS, in the beauty of Tasmania's most stunning coastal wilderness area. CROWDS, You can bring your stress if you like, but you can't take it home with you. I -LAWS, Please send me a complimentary copy of your brochure. PARK.I GTICKETS Name .... OR SMOG. Address ... Ph (. .... ) .. .. ..... ........... But we still call it ho111,e. Send this coupon to: PO Box 225 Kings Meadows TAS 7249 Ph (03) 6257 0 IOI Fax (03) 6257 0278 Frey in t Lodge .f" TIV ITI ES fR(YCINET Nt\TIONt\l l';\IU,•COLES SAY J- A WOR LD OF /\.TUR AL A NATU RE AUSTRALIA WINTER 1999 bz HOME GECKONOMICS For Lesueur's Velvet Gecko, a discerning sense of smell can Nature mean the difference between WINTER 19 99 VOLUME 26 NUMBER 5 life, death and a warm place Published by the Australian Museum Trust to slee/J. 6 College Street, BY SHARON J. DOWNES Sydney, SW 2000. Phone: (02) 9320 6000 46 Fax: (02) 9320 6073 Web: http:/ /www.austmus.gov.au Trust President: Malcolm Long Museum Director: Michael Archer MAJ AGING EDITOR Jennifer Saunders, B.Sc. email: [email protected] CIENTIFIC EDITOR Georgina Hickey, B.Sc. email: [email protected] PHOTO & EDITORIAL RESEARCHER Kate Lowe email: [email protected] RIVETING SEX IN THE DESIG AND PRODUCTIO GIANT SQUIDS Watch This! Design When a 220-lzilogram female PRINT! 1G was hauled up from the murlzy Excel Printing depths off Tasmania, scientists were amazed to find sperm ADVERTISI G cords embedded in her arms­ THE BIG CHILL Robbie Muller the first-ever evidence of mating The Earth freezes for thousands Phone: (02) 9320 6119 in giant squids. of years and then it thaws. Not email: [email protected] BY MARK ORMAN just once, but again and again. SUBSCR.IPTIO S 24 Why?And what does our planet Robbie Muller have in store for us? Phone: (02) 9320 6119 BY GEOFF McNAMARA Toll-free (1800) 028 558 RAISING BOOBIES Fax: (02) 9320 6073 The trials of life for a booby 54 email: [email protected] chicli begin almost before it has hatched. Parental inadequacy, Annual subscription (4 issues) accidents, bad weather and Within Australia $A33 Other countries $A45 Two-year subscription (8 issues) predators all talze their toll, Within Australia $A63 Other countries $A83 maliing life hell in paradise. Three-year subscription (12 issues) BY MYRIAM PREKER Within Australia $A89 Other countries $A116 1 ew subscriptions can be made by credit card on the NATURE 28 AUSTRALIAtoll-free hotline (1800) 028 558 or use the form in this magazine. If it has been removed, send cheque. money LAND OF THE LONGTAILS order or credit card authorisation to the address above, made In the drier rainforest scrubs of payable to the 'Australian Museum' in Australian currency. northern Queensland, could All materialappearing i11 NATURE AUSTRALIA is copyright. Reproduction in part or whole is not permitted without written long tails and braininess be a11thorisatio11 from the Editor. NATURE AUSTRALIA welcomes linked? articles on the natural and cultural heritage of the Australian BY ROGER MARTIN Region. Opinions expressed by the authors are their own and do not necessarily represent the poHcies or views of the Au tralian 38 Museum. NATURE AUSTRALIA is printed on archival quality paper suitable for library collections. Published 1999 ISSN-1324-2598 NATURE AUSTRALIA (asA H) @ is proud winner of the 1987, '88, '89, '90, '91, '92 & '93 Whitley Awards for Best Periodical, and the 1988 & '90 Australian Heritage Awards.