Antler rubbing of yellow-wood by Sambar in East Gippsland, Victoria

2013·2.3 MB·English

by  Rohan J Bilney

Research Reports
Antler rubbing ofYellow-woodby Sambar
in East Gippsland, Victoria
Rohan Bilney
J
POBox988,Bairnsdale,Victoria3875.Email:[email protected]
Abstract
Surveysof49WarmTemperateRainforestgulliesinEastGippslandidentifieddiscretepopulationsofYellow-
woodAcronychia oblongifolia in 34gullies. Antler rubbingofYellow-wood by Sambar Cervus unicolorwas
obvious andwidespread in all 34gullies. Eight gullieswere randomly selectedto assesstheextentofantler
rubbingto100Yellow-woodplantsineachgully(50plantsclosetotworandomlygeneratedlocations).Across
alleightgulliesanaverageof64.6%(± 17.7sd;range36-92%)ofYellow-woodindividualswereantlerrubbed,
with51.0%(±17.8sd;range18-80%)subjectedtosevererubbing(>50%ringbarking),withmortalityrecorded
mm
at30.3%(± 14.0sd;range6-52%).Yellow-woodwithstemsintherange30-150 diameteratbreastheight
(DBH) weresubjectedtothehighestratesofantlerrubbing(73-81%),withsmallerstems(10-16mmDBH)
sufferingthehighestratesofmortality.Sambarrepresentamajorthreattothelong-termpersistenceofYellow-
woodandrainforestcommunitiesinEastGippsland.(TheVictorianNaturalist130(2)2013,68-74)
KeyWords: Cervusunicolor Acronychiaoblongifolia, deer, rainforest
,
Introduction
Sambar Cervus (Rusa) unicolor is a large deer in Victoria, Sambar are also listed under the
speciesnativetosouth-eastAsia(Bentley 1978; Wildlife Act 1975 as protected wildlife, due to
Bilney 2008). During the 1860s they were re- their status as a highlyvalued game species. It
leased into Victoria for recreational hunting is therefore illegal to harvest Sambar without
purposes,andhavesincebecomethemostsuc- a Victorian Game Licence (issued by Depart-
cessfully established deer species in Australia, mentofPrimaryIndustries) oranAuthorityto
occupyingmostforestedhabitatsinsouth-east- ControlWildlifePermit(issuedbyDepartment
ernAustralia(Bentley1978;Moriarty2004;Peel of Sustainability and Environment). Overall,
etal. 2005;Gormleyetal 2011).Itspopulation there is apressing need to develop aneffective
size and distribution is continuing to increase andappropriatemanagementstrategyforSam-
insouth-easternAustralia(Moriarty2004;Peel bar,butthisprocessishamperedbythemeagre
et al. 2005; Gormley et al. 2011), despite con- ecological information that has been gathered
siderablerecreational huntingeffort (estimates onSambarandtheirecological impact inAus-
ofannuallegalharvestfor2009-2011 inVicto- tralia(e.g. Peeletal. 2005;Bennett2008).
riawerebetween 28762 and34368 individuals Quantifying ecological impacts ofSambar is
(GormleyandTurnbull2010,2011). challenging, especially differentiating between
Concern is mounting about the ecological browsing impacts caused by other herbivore
impactscausedbySambar;however,theextent species (bothnativeandexotic).Thisresultsin
and severity of their impacts remain poorly conjecture about the extent oftheir ecological
understood (Stockwell 2003; Peel et al. 2005; impacts (e.g. Hall and Gill 2005; Bennett and
Scientific AdvisoryCommittee 2007a; Bennett Coulson 2008); however, there is nothing con-
2008). In the state ofVictoria, Sambar has re- jectural about the observed impacts caused by
cently been listed under the Flora and Fauna antlerrubbingbecausenativemammalsdonot
Guarantee Act 1988 as a ‘potentially threaten- possess antlers. Deer primarily rub antlers on
ingprocess’tobiodiversity,whileinNewSouth trees to remove velvet from fully grown ant-
Wales, Sambar, along with all other feral deer lers,forscentmarkingtodefineterritories,and
species, is listed under the Threatened Spe- potentiallyforstrengtheningmusclesforfight-
cies Conservation Act 1995 as a ‘key threaten- ing (Bentley 1978; Gill 1992). Particular plant
ing process’ (NSW Scientific Committee 2005; species areoftentargeteddue totheir aromatic
Scientific Advisory Committee 2007a). Yet, properties, size and physical structure, so this
68 TheVictorianNaturalist
Research Reports
activity can result in a considerable impact on trees or fewer, while some populations can ex-
someplantspecies (KileandMarchinton 1977; ceedseveralthousand(pers.obs.).
BennerandBowyer1988;Johanssonetal. 1995; The aim of this study was to assess Sambar
BennettandCoulson2011). antler rubbing on Yellow-wood in eight popu-
One plant species observed to suffer severe lations throughouttheknown range ofYellow-
and targeted antler rubbing is the rare and wood in Victoria, to evaluate the impacts of
threatenedYellow-woodAcronychiaoblongifolia Sambarantlerrubbing.
(Peeletal 2005;ScientificAdvisoryCommittee Methods
w20o0o7db;iPseerles2tr0i1c0t)ed(Ftiog.c1o).mmIunnViitciteorsiao,fYeWlalorwm- oBfetwWeaernm20T0e2mpaenrdat2e008R,aimnofsortesktno(wbnasesdtanodns
Temperate Rainforest, Dry Rainforest and Lit- Ecological Vegetation Class maps available
toralRainforestatlowelevationsinthefoothills on-line from the Department ofSustainability
and coastal forests between the Mitchell River
and Environment http://www.dse.vic.gov.au/
andtheBemmRiverinEastGippsland(anarea about-dse/interactive-maps) were surveyed
approximately 150 km in length) (Costermans from foothill and coastal forests (below400 m
1983; Peel 1999). Itisathicket-forming species elevation) between the Mitchell River in the
relying on site occupation by root-suckering west and the Snowy River in the east (exclud-
once the original seedling has established. As
ing the Snowy River catchment, but including
a canopy component, it is generally sparsely Cabbage Tree Creekapproximately 10 km east
and patchily distributed throughout rainforest ofthe Snowy River). The surveyarea incorpo-
patches. In some gullies the entire population ratedmostoftheknownpopulationsofYellow-
may number only several hundred individual wood in Victoria (except for the Snowy River
Fig. 1.Astandof17Yellow-wood,allseverelyantlerrubbedbySambar.
Vol 130 (2) 2013 69
Research Reports
and Bemm River catchments) (Flora Informa- tent ofantler rubbing did not always correlate
tion System, Department ofSustainability and with treehealth.Thisisbecauseofthediffering
Environment, Viridans Biological Database: time since antler rubbing (ranging from sev-
accessedMay2005). eral days to several years), and tree health ap-
Atotalof49isolatedstandsofWarmTemper- peared to deteriorate with time since rubbing.
ate Rainforestweresurveyed and Yellow-wood Theextentofantlerrubbingdamagetothebark
wasdetectedin34(12sitesintheMitchellRiv- therefore appeared a more consistent measure
er catchment, nine in the Tambo River catch- ofantlerrubbingimpact. Surveystoassessant-
ment, two in the Tara Range, 10 in the Lakes ler rubbingwere conducted between 2010 and
Entrance/Lake Tyers area, and one at Cabbage early2012.
Tree Creek). At all 34sites, Sambarantlerrub- Statistical procedures including Chi-square
bing on Yellow-wood was obvious and wide- tests,MannWhitney UtestsandKruskal-Wal-
spread. Eight of the 34 sites were randomly listestswereconductedusingSPSSversion 16.0
selected to assess the extent ofantler rubbing (SPSSInc,Chicago, Illinois).
on Yellow-wood (three sites from the Mitchell
Results
River catchment, two from the Tambo River A total of 800 individual Yellow-wood stems
catchment and three from Lake Tyers). These
wasassessedforantlerrubbingacross 16stands
siteswereselectedbyconsecutivelynumbering
allYellow-woodpopulationswithanumberbe- ineightgulliesin East Gippsland. Acrossthese
tweenoneand34andrandomlyselectingeight sites, an average of64.6% (± 17.7sd, range 36-
numbersbetween 1 and 34. Gulliessupporting 92%)ofYellow-woodstemshadbeensubjected
Yellow-woodpopulationsoflessthan 100indi- to antlerrubbing,with 51.0% (± 17.8 sd, range
18-80%) experiencing severe rubbing or death
vidualswerenotanalysed.
A total of 100 Yellow-wood stems was as- (Table 1).
sessed for antler rubbing in each gully, and Sizeclassofstemsrubbed
this required assessing the 50 plants closest to Sambar antler-rubbed Yellow-wood stems of
two randomly generated locations within each all sizes (including the largest tree recorded at
gully. Steep rocky terrain was avoided and all 312 mm DBH), although the extent ofantler
surveyswereconducted near thegully flooror rubbing and its impact varied depending on
onlowerslopesofgullies. stem diameter (Figs. 2 and 3). Smaller (<30
For each Yellow-wood stem, the diameter at mm) and larger stems (>150 mm) were sub-
breast height (DBH) was recorded. However, jectedtoreducedratesofrubbingcomparedto
stumps ofYellow-wood stems (<1 minheight) theiravailability(X2= 11.379,df=5,p=0.044)
that had been killed by antler rubbing were (Fig. 2), while stem DBH also differed signifi-
measured at their highest point, which was cantlybetweenrubbed(mean;54mm±4.1 sd)
considered to still closely resemble the trees and non-rubbed stems (45 mm ± 5.0 sd) (U=
DBH. Individualswithstemdiameters<10mm 53,799,p<0.001).
or which had died without any apparent sign There were significant differences relating
of antler damage were not assessed. Antler- to average stem DBH and the extent of rub-
rubbedYellow-woodwerecategorisedaseither bing (H= 55.798,df=2,p <0.001),with mod-
mm
‘Dead’ (obviously antler-rubbed with a dead erately rubbed stems (76 ± 5.5 sd) being
maintrunkwithorwithoutregeneratingbasal/ larger than severely rubbed stems (alive and
coppicing shoots and therefore considered ef- dead) (48mm±3.4sd),whichwerelargerthan
fectively dead) or ‘Alive’ (with leaves). The ex- non-rubbedstems.Severelyrubbeddeadstems
mm
tentofantlerrubbingwasallocatedtothreecat- (37 ± 2.2 sd) on average had significantly
egories: ‘Severe’ where over halfofthe trunk’s smaller DBH than severely rubbed alive stems
mm
outer-bark is removed, ‘Moderate’ with less (65 ± 4.0 sd) (U= 10352,p = <0.001), in-
than halfofthetrunk’souter-barkremoved, or dicating that larger trees were more resilient
‘None’ (non-rubbed). An assessmentoffoliage to surviving antler damage than smaller trees.
cover was rejected as a measure oftree health Thelargestdeadstemwithantlerrubbinghada
primarily because it was apparent that the ex- DBH of127mm. As DBH increased, the sever-
70 TheVictorianNaturalist
Research Reports
Table1.TheextentofdamagecausedbySambarantlerrubbingto16standsofYellowwoodacrosseightpopu-
lations,totalling800individualsinEastGippsland.
Plantconditionandextentofantlerrubdamage % sd Range(%)
Minimum Maximum
Alive-None 35.4 17.7 8 64
Alive-Moderate(<50%ringbarked) 13.6 8.5 2 28
Alive-Severe(>50%ringbarked) 20.8 9.1 2 32
Dead-Antlerrubbed 30.3 14.0 6 52
ityofantler rubbing declined, along with rates rubbed treestypicallyappearingtobeinbetter
ofmortality(Fig. 3). condition than older rubbed trees. The time to
death was likely to be correlated with the de-
Discussion gree of ringbarking, with complete ringbark-
The extent and severity ofdamage inflicted by ing typically inducing mortality quickly, while
SambarantlerrubbingonYellow-woodisofse- many severely and even moderately rubbed
riousconservationconcern.Eventhelowestre- plants progressively declined in health, even-
cordedrateofantlerrubbingtoasinglepopula- tually resulting in mortality. Most trees sub-
tion was high (at 36%), while at the other end jected to severe antler rubbing were partially
of the spectrum, the most severely observed dead with several dead limbs and significantly
damage(at92%,with52%mortality)isofgrave reduced foliage cover, and manytrees were ex-
concern. Ofadditional concern is the limited pectedtodiesoon. Someolderplantsappeared
time-frame in which such extensive damage to have died from minimal ringbarking, pos-
has been inflicted, with Sambar occupying the sibly due to infection from the wound caused
studyareaonlyinthelast50years (foothillfor- byantlerrubbing(e.g.Stewart2001).Undoubt-
ests)to25years (coastalforests) (e.g. Peeletal. edly,thelevelsofmortalityatthesesiteswillin-
2005). crease progressively over time (irrespective of
Mortalitywastheonlymeasureoftreehealth continued additional antler rubbing), and this
recordedinthisstudy,primarilybecauseitwas study has underestimatedthe inevitable extent
apparent that the current health of trees did ofmortality. Long-term studies on the health
notappeartobeasuitablemeasureofthetrees’ of individual rub-trees will be important for
long-term health.Thiswasdue tothevariation evaluatingthetrueextentofmortalityinduced
in time since trees were rubbed, with recently byantlerrubbing.
45 70
StemDBH
StemDiameter Moderate —Severe*Dead ***Severe —-Dead
wFiigt.h2t.heTpheercaevnatialgabeilainttyleorfruYbebleldowb-ywoSoadmbcaormpinardiefd- rFiugb.bi3.ngThoenpYeerlclenotwa-gweoofdreoqfuednifcfyeraenndtesxtteemntDoBfHantsliezre
ferent sizeclasses. Percentages rubbed aredisplayed classes,includingthelevelofmortality(Dead).
inwhite.
Vol 130 (2) 2013 71
Research Reports
Fig.4.MortalityofbothamatureYellow-woodstem (nowastump) andresproutingstem(horizontalstem),
causedbyantlerrubbing.
Despite the high levels ofmortality that are forest canopy species, provides by facilitating
occurring, Yellow-wood trees often re-sprout crucial ecological processes within rainfor-
from stems below antler rubs and/or sucker est communities. A combination of mortality
from roots. Yellow-wood therefore has the and impaired health caused by antler rubbing
potential to persist in areas subjected to high dramatically reduces foliage cover (e.g. Ben-
levels ofadult stemmortality; however, the re- nett and Coulson 2011; pers. obs.) and results
generation is often subjected to antler rubbing in increased light penetration to the rainforest
onceitreachessuitablesize(Fig.4),sotheplant floor, affecting moisture retention (rainforest
hasalimitedcapacitytoreachmaturity. There- drying), regeneration dynamics, the encroach-
fore, the short-term ability forYellow-wood to ment of non-rainforest plants, increased sus-
persist at sites with continued antler rubbing ceptibilitytofireandpotentiallyrainforestcon-
is high, but the long-term survival ofYellow- traction and loss (Peel etal. 2005). Ofconcern
woodis in doubt given that its primaryregen- is that this is occurring due to antler rubbing
erativemechanismfortherenewalofthestand aloneandirrespectiveoftheimpactscausedby
andindividualisdramaticallyaffected. heavybrowsingpressure (Peeletal. 2005).This
The ecological impact of antler rubbing by disruption andprevention ofcrucial rainforest
Sambar on Yellow-wood trees is not restricted ecological processes is overwhelmingly appar-
to the individual tree, but includes impacts ent at one coastal study site (Lake Bunga) in
on the entire plant community (rainforest) in particular where Yellow-wood dominates the
which it grows. This is primarily due to the rainforestcanopyandtherehasbeenadramat-
importantrolethatYellow-wood,likeanyrain- ic transformation ofthe entire stand ofrain-
72 TheVictorianNaturalist
Research Reports
forest within the past eight years (pers. obs.). Yellow-wood trees also appear to have been
At this site, there are only 179 Yellow-wood abandonedfollowingrubbingandmortality(or
individuals in the entire gully, and 87.2% have reduced foliage cover) ofnearby Yellow-wood
beenseverelyrubbed,resulting in46% mortal- trees(pers.obs.).
ity.Therainforestcommunitiesthatexistatthis Studiesofantlerrubbingbyotherdeerspecies
site include Littoral Rainforest (listed as Criti- reveal that Yellow-wood seems to possess sev-
cally Endangered under the Commonwealth eral characteristicsthat are preferred forantler
Governments Environment Protection and rubbing, including stem DBH, smooth bark,
BiodiversityConservationAct 1999). considerableheighttofirstbranchandaromat-
Severalanimalspeciesarelikelytobeaffected ic properties (Kile and Marchinton 1977; Ben-
by Sambar damage to Yellow-wood. Yellow- ner and Bowyer 1988; Johansson et al. 1995).
woodfruitsinsomeyearsonly(possiblycorre- Yellow-wood isaparticularlyaromaticspecies,
latingwith rainfallor moisture), usuallyin late fromthefamilyRutaceae,andanothermember
spring or early summer. Several bird species ofthefamilytargetedbySambarforantlerrub-
consumethefruitandaidinseeddispersal(e.g. bingincludesthethreatenedShinyNematolepis
Satin Bowerbird Ptilonorhynchus violaceus, Nematolepis wilsonii, which isrestrictedtotwo
Pied Currawong Strepera graculina), includ- populationsintheupperYarraRivercatchment
ingthemigratoryTopknotPigeonLopholaimus (BennettandCoulson 2011).
antarcticus thatreaches its mostsouth-western ItshouldbenotedthatYellow-woodcangrow
distribution limit in this study area (e.g. Bar- at rainforest margins in mid to upperslopes of
rett etal. 2003). FruitingYellow-wood is likely rainforest gullies and in steep rocky areas, yet
to provide an important food source for the this study targeted only gully floor environ-
Topknot Pigeon, since in years when Yellow- ments. Therefore, the extent ofantler rubbing
wood fails to fruit, Topknot Pigeons are rarely documented in this paper may not represent
observedinthestudyarea(pers.obs.). Reduced the extent of antler rubbing that is occurring
fruitingasaconsequenceofantlerrubbingwill throughout Yellow-wood stands. For example,
resultinreducedfoodforthesespecies. some large stands of Yellow-wood exist that
TheYellow-spotted Jezebel Delias nysa is an- have been subjected to only minimal antler
otherrainforest-dependentspeciesthatreaches rubbing.Ontheotherhand,therearealsosites,
itsmostsouth-westerndistributionlimitinEast especially small stands, where damage is more
Gippsland (recorded east of Lakes Entrance) severe (e.g. one stand of32 trees has suffered
(Braby2000; Peel 2010). Adults have been ob- 100% mortality).
served feeding on the nectar of Yellow-wood
Management
and using thetreesasafocus forsocial activity The magnitude of the impact of Sambar on
prior to mating (Peel 2010). Their larvae feed
Yellow-wood and rainforestcommunities war-
exclusively on the stems of Jointed Mistletoe
rants immediate conservation management
Korthalsella rubra a species restricted to rain-
, attention. This urgency is increasing as the
forest(Braby2000; Peel2010).
population and distribution of Sambar con-
Rainforest provides dense foliage cover suit-
tinueto expand. Unfortunately, currentlythere
Oabwlle aTsytroootsetnienbgrisciotseasafonrdtPhoewetrhfreualtOenweldNSionootxy is no feasible management option available for
reducing the ecological impacts ofSambar on
strenua (Bilney et al. 2011). Both owl spe-
cies have been recorded roosting in and near the scale that is warranted. Exclusion fenc-
Yellow-woodtrees(Bilneyetal. 2011).Fourre- Yineglliosw-onwloyodf,easdiubeletofotrhesmtahlelsicsaloel,ateexdpsetnasnedsanodf
cordedroosttreesinYellow-wood(fromatotal
of six) have subsequently been antler-rubbed practicalityoffencingthatisrequired.Targeted
by Sambar, resulting in reduced foliage cover hunting at particular sites again is neither fea-
siblenoreffectivedue tothescale ofthethreat.
and abandonment of these trees as roosting
Hunting, especially of dominant stags, could
sites (pers. obs.). Fouradditional roosting sites
potentiallyresultinthedisruptionofterritories
in other rainforest canopy species located near
andincreaseterritorialdisputes,resultinginin-
Vol 130 (2) 2013 73
Research Reports
creasedsignmarkingbysubordinatesandthus InstituteforEnvironmentalResearch,TechnicalReportSe-
resultinincreasedrubdamage.Lethalmanage- riesNo.210. (Department ofSustainabilityandEnviron-
ment:Melbourne)
ment options that target females would there- GormleyAMandTurnbull JD (2011) Estimatesofharvest
forebepreferred. fordeer,duckandquailinVictoria: Resultsfromsurveys
ofVictorianGameLicenceHoldersin2011.ArthurRylah
Overall,there isanurgentneedtoreducethe InstituteforEnvironmentalResearch,TechnicalReportSe-
population density ofSambar across the land- riesNo.224. (DepartmentofSustainabilityandEnviron-
ment,Melbourne)
scape. This will require research into control GormleyAM,ForsythDM,GriffioenP,LindemanM,Ram-
options, as well as increasing our understand- sey DSL, Scroggie MP and Woodford L (2011) Using
ingoftheirgeneralbiologyandecologyinAus- cpurrerseenntcea-nodnlpyotaenndtiaplredsiesntcrieb-uatbisoennscoefdeasttaabtloisehsetdimiantveastihvee
tralianecosystems.Identifyingandimplement- species.JournalofAppliedEcology48,25-34.
ing effective control methods for Sambar may Hall G P and Gill KP (2005) Management ofwild deerin
Australia.JournalofWildlifeManagement69,837-844.
represent one ofthe greatest challenges facing Johansson A, LibergO and Wahlstrom LK (1995) Tempo-
landmanagersandconservation agencies. ralandphysicalcharacteristicsofscrapingandrubbingin
roedeer(Capreoluscapreolus).JournalofMammalogy76,
Acknowledgements 123-129.
Thanks to David Cameron, Bill Peel and Neville KialendTLscaranpdesM:arScpahtiinalt,onteRmLpo(r1a9l77a)ndWhiphtyes-itcaaillecdhadreaecrterruibss-
Walshfortheirvaluablecommentsonanearlierdraft tics andsocial role. TheAmerican MidlandNaturalist97,
ofthispaper. 257-266.
Moriarty A (2004) The liberation, distribution, abundance
References and management ofwild deer in Australia. Wildlife Re-
BarRre(t2t00G3,)STihleconckeswAa,tlaBsarorfyAuSs,trCaulninaninbigrhdsa.m(RRoyaanldAuPsoturlatle-r NSseWarcThhr3e1a,t2e9n1e-d29S9pe.ciesConservationAct1995.
asianOrnithologistsUnion:HawthornEast) NSWScientificCommittee (2005) Herbivoryandenviron-
BennerJMandBowyerRT(1988)Selectionoftreesforrubs mentaldegradationcausedbyferaldeer.FinalDetermina-
bywhite-taileddeerinMaine.JournalofMammalogy69, tion. (New South Wales Scientific Committee, National
624-627. ParksandWildlifeService:Sydney)
BetnhneetYtarAra(R20a0n8g)esThNeatiimopnaacltsPaorfk.Sa(mUbnapurb(lCiesrhveudsPuhniDcoTlhoers)isi,n PeeVlicBtor(i1a9.99()DeRpaainrftomreensttsoafnNdatcuoorlalteRmepseoruartceesmiaxneddfEonrveisrtsono-f
TheUniversityofMelbourne) ment:Melbourne)
Bennett A and Coulson G (2011) The impacts ofSambar PeelB(2010)Rainforestrestorationmanualforsouth-eastern
(Cervus unicolor) on the threatened Shiny Nematolepis Australia.(CSIROPublishing:Melbourne)
(Nematolepis wilsonii). Pacific Conservation Biology 16, PeelB,BilneyRJandBilneyRJ(2005)Observationsoftheec-
251-260. ologicalimpactsofSambarCervusunicolorinEastGipps-
BennettAandCoulsonG(2008)Evaluationofanexclusion land,Victoria, withreferencetodestruction ofrainforest
plotdesignfordeterminingtheimpactsofnativeandex- communities.TheVictorianNaturalist122,189-200.
oticherbivoresonforestunderstoreys.AustralianMamm- ScientificAdvisoryCommittee(2007a)FinalRecommenda-
alogy30,83-87. tiononanominationforlisting:Reductioninbiodiversity
Bentley A (1978) An introduction to the Deer ofAustralia ofnativevegetationbySambar(Cervusunicolor).Nomina-
- with special reference to Victoria. (Forests Commission tionno. 756.FloraandFaunaGuarantee, ScientificAdvi-
Victoria:Melbourne) soryCommittee.(DepartmentofSustainabilityandEnvi-
BilneyRJ(2008) Sambar Cervusunicolor. In TheMammals ronment:Melbourne)
ofAustralia,3edn,pp.777-778.EdsSMVanDyckandR ScientificAdvisoryCommittee(2007b)FinalRecommenda-
BilStnreayhaRnJ,.C(RoeoekdeNRewanHdolWlhaindt:eSJyd(n20e1y1)) Potentialcompeti- otbiloonngoinfoalinao).miNnoamtiinoantifoornlinsot.ing7:64Y.elFlloorwa-waonoddF(aAucnraonGyucahri-a
tionbetweentwotop-orderpredatorsfollowingadramatic antee,ScientificAdvisoryCommittee.(DepartmentofSus-
contraction in the diversity oftheir prey base. Animal tainabilityandEnvironment,Melbourne)
Biology61,29-47. SPSSInc(2007)SPSSforWindowsversion 16.0Chicago,Il-
BrabyMF(2000)ButterfliesofAustralia: Theiridentification, linois
biologyanddistribution.(CSIROPublishing:Melbourne) StewartAJA(2001)Theimpactofdeeronlowlandwoodland
CostermansL(1983)Nativetreesandshrubsofsouth-eastern invertebrates: areviewofthe evidence and priorities for
Australia.(NewHollandPublishers:Sydney) futurereMsearch.Forestry74,259-270.
DepartmentofSustainabilityandEnvironment http://www. Stockwell (2003) Assessingthe levels and potential im-
Flodrsae.Ivnifc.ogromva.taiuo/nabSoyustt-edms,e/Dienptearratcmteinvet-moafpSsustainabilityand pUapcptesrofYabrrroawsCiantgchbmyenSta,mbViacrtoDreiea.r((UCnepruvbulsiusnhiecdolBorS)ciHnotnhse
Environment,ViridansBiologicalDatabase:accessedMay Thesis,MonashUniversity)
2005.
GillRMA(1992)Areviewofdamagebymammalsinnorth
GotremmlpeeryatAeMforaensdtsT1u.rDnebeurl.lFJorDes(t2r0y1605),E1s4t5i-m1a6t9e.sofharvest
fordeer,duckandquailinVictoria: Resultsfromsurveys
ofVictorianGameLicenceHoldersin2010.ArthurRylah
Received2August2012;accepted13December2012
74 TheVictorianNaturalist