Tree-Kangaroos of Australia and New Guinea

169 Pages·2005·3.801 MB·English

by  Roger Martin

AUSTRALIAN NATURAL HISTORY SERIES
-
TREE KANGAROOS
OF AUSTRALIA AND NEW GUINEA
Roger Martin
TREE-KANGAROOS
OF AUSTRALIA AND NEW GUINEA
ForCharlie Roberts
North Queensland Bushman
TREE-KANGAROOS
OF AUSTRALIA AND NEW GUINEA
Roger Martin
Illustrated by Sue Simpson
© Roger Martin 2005
All rights reserved. Except under the conditions described in the Australian
Copyright Act 1968 and subsequent amendments, no part of this publication
may be reproduced, stored in a retrieval system or transmitted in any form or
by any means, electronic, mechanical, photocopying, recording, duplicating
or otherwise, without the prior permission of the copyright owner. Contact
CSIRO PUBLISHING for all permission requests.
National Library of Australia Cataloguing-in-Publication entry
Martin, Roger William, 1946– .
Tree-kangaroos of Australia and New Guinea.
Bibliography.
Includes index.
ISBN 0 643 09072 X.
1. Tree kangaroos – Australia. 2. Tree kangaroos – New
Guinea. I. Simpson, Sue. II. CSIRO. III. Title. (Series :
Australian natural history series).
599.22
Available from
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Front cover
Finsch’s Tree-kangaroo (Dendrolagus inustus finschi)
Photo by Roger W. Martin
Back cover
Riverine complex forest of the Annan River
Photo by Roger W. Martin
Author photo by Courtney Booker
Set in 10.5/14 Sabon
Cover and text design by James Kelly
Typeset by J&M Typesetting
Printed in Australia by Ligare
Preface
This book is a summary of current knowledge on the biology and natural
history of tree-kangaroos. While there are 10 species currently described, read-
ers will find a heavy emphasis placed on the two Australian species, Bennett’s
Tree-kangaroo (Dendrolagus bennettianus) and Lumholtz’s Tree-kangaroo
(Dendrolagus lumholtzi). In a book that purports to be on the tree-kangaroos
of both Australia and New Guinea this is an unfortunate bias but it is an accu-
rate reflection of the present state of knowledge. Largely because they are rela-
tively abundant and far more accessible to wildlife biologists, almost all recent
field research on tree-kangaroos has been done on Australian species. There is
still comparatively little known about the New Guinea species.
Readers will also find that of the two Australian species I focus more on
Bennett’s Tree-kangaroo, particularly when discussing the finer points of tree-
kangaroo natural history. The main reason for this is that it is the species I
know best. Apart from a brief period spent working on Scott’s and Grizzled
Tree-kangaroos in New Guinea, and the odd foray working on Lumholtz’s
Tree-kangaroo, almost all tree-kangaroo research I have done over the past 15
years has been on this species.
When I started my field studies of Bennett’s I wasn’t planning a comparative
study of all members of the genus. I was simply trying to determine the con-
servation status of this one species, which was very poorly known at the time.
However, as the work progressed and I became more familiar with Bennett’s
Tree-kangaroo and its habits, ‘dendrolagophilia’ set in. I realised I was dealing
with a truly extraordinary marsupial and this led me to ask broader questions
about the biology and origins of the genus as a whole. It is only now, in writing
this book and attempting to give plain answers to these questions, that I realise
the serendipity involved in selecting Bennett’s Tree-kangaroo as a study animal
in the first place. It has given me insights into tree-kangaroo biology that I
doubt would have been available had I studied any other species.
For a start, Bennett’s Tree-kangaroo belongs to the ancestral grade of tree-
kangaroos. That is, with its two sister taxa Lumholtz’s and the Grizzled Tree-
kangaroo, it is thought to be the least differentiated from the original stock of
kangaroos that abandoned their terrestrial ways and took to living in the trees.
And thus it is directly linked to the big question, the great paradox of kan-
garoo evolution: why did an animal so beautifully adapted for terrestrial living
vi Tree-kangaroos of Australia and New Guinea
abandon all to take up an arboreal lifestyle? Knowledge of Bennett’s Tree-kan-
garoo and its natural history has provided some important clues towards an
answer to this question.
The most important clues have come from its use of habitat. Bennett’s
Tree-kangaroo occupies a wide range of habitat types – wider in fact than any
other species of tree-kangaroo. Upland montane rainforest was its presumed
preferred habitat at the outset of my studies, but Bennett’s proved equally
populous in the lowland monsoon forests. It even occupied the sparse riverine
forests clothing the creeks meandering through the dry country on their way
to the Coral Sea.
A major difficulty usually encountered when studying tree-kangaroos is
their rareness but, in part because of its widespread habitat, this wasn’t the
case with Bennett’s. As well, populations of Bennett’s Tree-kangaroo were
both undisturbed and secure in these habitats (most of them being in World
Heritage areas). The populations were also free of hunting pressure. Over-
hunting is the main reason New Guinea tree-kangaroos are rare and although
the indigenous inhabitants of Australia’s wet tropics also used to be avid tree-
kangaroo hunters, they ceased the practice more than 50 years ago. As a con-
sequence, Bennett’s Tree-kangaroo is now populous – probably as populous as
it has been since the last Ice Age.
The other great advantage of such a focus on Bennett’s Tree-kangaroo,
particularly when writing a natural history such as this, is the long period over
which it has attracted notice and been written about. It was the first tree-kan-
garoo reported in Australia and the first to be caught live and held in cap-
tivity here. Many eminent zoologists (Richard Semon, George Tate, Hobart
Van Deusen) have visited the Bloomfield River district in search of Bennett’s
Tree-kangaroo and there is an extensive literature of their various quests from
which much can be learnt.
For these reasons I hope my bias is understood and appreciated for the
insights it provides. Even so, there have been relatively few field studies on
tree-kangaroos and we still know very little about them. Few Australians are
even aware of their existence. An earlier natural history (by Tim Flannery,
Alexandra Szalay and me, with beautiful illustrations by Peter Schouten), pub-
lished in 1996, reached fewer people than we had hoped, so this current book
aims to introduce tree-kangaroos to the wide audience they deserve.
Tree-kangaroos have a notoriously long period of gestation and, in keeping
with this, so did this book. Many people have assisted me over the years and I
am very much in their debt.
Over the time I spent doing fieldwork in the Bloomfield River area, I
received help from many local residents. Pre-eminent among these are Lewis,
Preface vii
Charlie and Edith Roberts from Shipton’s Flat and Rob and Ruth Whiston
from Gap Creek. My work on Bennett’s Tree-kangaroo could not have been
done without them. I also thank Viare Kula, Oscar Kirsch, Tom Veitch, Geoff
Waldeck and Bruce and Sue Simpson.
I am grateful to John Elliott, Scientific Editor of UNSW Press, for first elic-
iting and then offering to publish a book on the natural history of tree-kan-
garoos. Unfortunately the UNSW Press’s Natural History series was finished
before the book.
The book has been written under a number of different roofs and I am
indebted to Peter McCarthy, Arthur Blackham, Amanda Embury and particu-
larly Amy Shima for their hospitality.
I would like to thank William Foley, John Nelson, Will Betz and Lisa
Dabek for allowing me access to their unpublished material on tree-kangaroos
and for permitting me to quote from it. I am also grateful to Ian Beveridge for
giving me some of his precious time to discuss the intricacies of tree-kangaroo
parasites. I thank Peter Johnson for allowing me access to his captive animals
at Pallarenda, Queensland.
Ian and Keith Stewart were also very generous with their time and exper-
tise in scanning images of tree-kangaroos for me. David Humphrey, from the
Department of Photography at Monash University also photographed some
material. I would also like to thank Gerald Cubitt, John Nelson and Dan Irby
for allowing me to use their photographs.
I am grateful to Tim Flannery for facilitating a couple of trips to New
Guinea that allowed me to get a first-hand impression of field research on tree-
kangaroos in that country.
I thank the staff of the Australian Museum Library in Sydney for their
assistance in providing reference material from some of the rarer books and
journals in their collection. I also thank Ralph Schmit, Dermot Henry and Tom
Rich from Museum Victoria for locating and making available fossil material
in their care.
Michael Kearney, Nicole Kearney and Chris Johnson read and commented
on earlier versions of this work and I am particularly grateful to them. As I am
to Sue Simpson for the magnificent job she did in drawing the majority of the
illustrations in this book.
Finally I would like to thank Amy Shima for her enduring good judgment
throughout the many discussions we had about this book, as well as for her
support and encouragement during the final stages of its writing.
Roger Martin

Contents
Preface v
1 A tree-climbing kangaroo? 1
2 Tree-kangaroo taxonomy 15
3 Adaptations for an arboreal life 25
4 The rainforest canopy: A bountiful world 35
5 Evolutionary history 63
6 The rainforest canopy: A dangerous world 83
7 Parasites, pathogens and other irritations 99
8 Population density and spatial requirements 109
9 Sex and reproduction 121
10 Conservation 133
Appendix: Basic information for each species 147
References 150
Index 156