The Eltham Copper Butterfly 'Paralucia Pyrodiscus Lucida' Crosby (Lepidoptera: Lycaenidae): Local versus State Conservation Strategies in Victoria

2007·2 MB·English

Invertebrate Conservation Issue
The Eltham Copper Butterfly Paraluciapywdiscus hicida
Crosby (Lepidoptera: Lycaenidae): local versus state
conservation strategies in Victoria
AA Canzano,' -’TR New' and Alan L Yen’
DepartmentofZoology,LaTrobcUniversity.Bundoora,Victoria3086
DepartmentofPrimaryIndustries.621 BurwoodHighway.Knoxfieid.Victoria3156
’Correspondingauthor
Abstract
This paper summarises some aspects ofthe practical conservation needs ofthe Eltham Copper
Butlerny Paraluciapyrodisciis lucida. a small threatened subspecies ofbuttertly endemic to
Victoria. Australia. The buttertly is located in threedisjunct regions, separated by hundreds ofkilo-
metresacrossthestateasaresultofhabitatremoval anddegradation. ThethreeareasofECBoccur-
rence each have distinct characteristics affecting the needs and intensity ofconservation manage-
ment on the various sites given their urban, regional and rural settings. Butterlly populations have
been monitored nearly every year since 1988 with the active support ofvolunteers. 'Friends of
ElthamCopperButterfly*, local councilsandgovernmentagencies.Thisinformation hascontributed
to a more holistic management regime for the butterlly, and further research aims to elucidate the
more intricate detailsofthebutterfly’s biology, to continue torefinethe current monitoring process
acrossthestateofVictoria.{TheVictorianNaturalist124(4),2007,236-242)
Introduction
The Eltham Copper Butterfly Paralucia nests by day, around the base ofthe food
pyrodisciis lucida Crosby (ECB) is a plant. ECB is unusual in that populations
Victorian endemic subspecies ofthe dull have been monitored nearly every year
copper. In common with many other since 1988 withthe activesupportand par-
Australian Lyeaenidae, it has declined in ticipation of community volunteers, such
range, and has become one of the best- as the 'Friends ofthe Eltham Copper’, and
known buttertly taxa in Victoria since a parallel groups associated with reserves in
thriving colony was discovered in Eltham, Castlemaine and Kiata. With their help,
outer Melbourne, in 1987. Before that, it counts have been made both ofcaterpillars
had been believed by many people to have andadultbutterflieseach season.
become extinct through site loss caused by In this note, we summarise some aspects
urban development since it was described ofthe practical conservation needs ofthe
from Greensborough in 1951. ECB was subspecies, anddraw attention to (a) differ-
amongst the first invertebrates to be listed ences between the management needs of
under the Flora andFauna GuaranteeAct ECB in three disjunct regions in which the
1988, and has become a powerful ambas- butterfly occurs and (b) differences
sadorfor insectconservation in the state. It between the various sites in the Eltham
is one of few Australian butterflies for area, forwhich different agencies have pri-
which dedicated reserves have been desig- mary management responsibility. Early
nated for its conservation. The butterfly’s conservation management plans and status
biology, outlined by Braby (1990) and evaluations (Crosby 1987; Vaughan 1988)
Braby et at. (1992, 1999), is reasonably have continued to form the basis for more
well understood. Endersby (1996) also recent advances, and enabled progress
contributed to the biology and behaviour toward more holistic management. The
ofECB with detailed field observations of conservation ofthe ECB is overseen by the
each of its life history stages. The senior Eltham Copper Butterfly Working Group,
authorofthispaperiscurrentlycompleting which comprises representatives ofthevar-
more detailed research on the ECB as part ious management agencies forthe different
ofahigherdegree dissertation. Caterpillars ECB sites, entomologists, scientists from
feed nocturnally on Bursaria spinosa^ and other relevant disciplines, and the relevant
are tended by ants ofthe genus Notoncus. Friendsgroups.
They are harboured in the ant subterranean
236 The Victorian Naturalist
Invertebrate Consef^ationIssue
Fig. I. The Eltham CopperButterfly locations at Kiata. The Kiata Flora Reserve hastwo sites, one
by the highway (1) and the other in the centre ofthe reserve (2). There is a small colony at the
SalisburyFloraReserve(3).
Distribution and its conservation spring. In contrast,twodistinctgenerations
implications occur in the Kiata area, where adults ofthe
The current distribution of the Eltham first generation appear from mid-October,
Copper Butterfly is believed to represent and ofthe second generation, in February.
the outcome ofconsiderable range reduc- PhenologyatCastlemaine also implies that
tion and habitat loss and fragmentation, to only one generation may occur. Different
leave three highly disjunct areas where the species ofNotoncus hostthe caterpillars in
butterfly now occurs (Figs. 1-3). Within different parts ofthe range: A. capitatus at
each region, the butterfly exhibits charac- Eltham and Castlemaine, and A. ectatom-
teristic patterns of seasonal development, moidesatKiata.
and within each the distribution is patchy The three areas ofECB occurrence each
and far less extensive than that of either have distinct characteristics affecting the
the larval food plant or the host ant. needs and intensity ofconservation man-
Phenology and development differs some- agementonthevarious sites.
whatin thedifferentregions, reflectingcli- (a) Kiata and Salisbury, in north-western
matic differences, and leading to different Victoria, harbourpopulations on sever-
monitoring needs in each area. At Eltham, al rural sites with patchy Bursar'ia,
a clear univoltine pattern occurs, but with within a largely pastoral area. Three
late emergences of adults in some years small colonies of the butterfly are
giving the appearance ofa second genera- knownon largeflorareserves(Fig. 1).
tion. Adults are present from November to (b) Castlemaine. Two peri-urban sites sup-
March, occasionally later. Eggs are laid port butterfly colonies, one within the
from November, and young caterpillars Botanic Gardens, and others, more
eclose in December, foraging little during recently discovered, in Kalimna Park.
the winter months but resuming regular These sites represent an urban/rural
activity as the weather warms in early transition, andare surroundedby amix-
Vol, 124 (4) 2007 237
Invertebrate Conservation Issue
ture ofresidential development, natural within reserves with wider conservation
bushland and grazing lands with ongo- responsibility. The sites thereby span the
ing subdivision for urban development range from large rural sites to small urban
(Fig. 2). ones. These are associated with different
(c) Eltham/Greensborough, in outer north threats and different opportunities for the
eastern Melbourne, where the butterfly butterfly to disperse and track resources.
occurs on several small (1-3 ha) urban Thus the larger sites afford opportunity for
remnant patches, surrounded and iso- population movement impossible on the
lated by housing. Six major colonies small Eltham sites.
are known, some of them small (Fig. Systematic annual larval and adult counts
3). The largest population, at the have been made at all three locations since
Western Colony, comprises fewerthan 1993.These have been conducted by pro-
800-1000 individuals. fessional entomologists (Van Praagh 1996;
All sites are nominally protected, some Canzano, unpubl. data), Department of
as dedicated reserves, and some by being Susutainability and Environment, Parks
238 The Victorian Naturalist
Invertebrate ConservationIssue
Victoria, and the Friends groups (Friends which acts as a clearing house and coordi-
of the Eltham Copper Butterfly and nator of information accruing.
Friends of Kalinina Park). These annual Management needs, and the capacity to
counts have provided significant informa- undertake effective management, differ
tion on distribution and relative abun- substantially across the different areas. At
dances of ECB, but the nature, intensity Kiata/Salisbury and Castlemaine the
and frequency of counts required to pro- potential habitat and sites are sufficiently
vide reliable quantitative data on ECB in extensive to facilitate a mosaic of condi-
these reserves remains uncertain. The tions within the area, and for the butterfly
results are influenced by weather condi- populations to track these as they change,
tionsanddifferencesin individual observer so that the butterfly presence and distribu-
acuity. tionmay differfrom yeartoyear, oracross
alongertime scale. Thus, the majorcolony
Progresstoward effectiveconservation in the Castlemaine Botanic Gardens has
As forotherbutterflies in Victoria, surveys moved from its stronghold in the early
continue to yield new information, both of 1990s to another site some hundreds of
detail and scale, with recent discoveries of metres away. Such microscale population
‘new’ colonies in Kalimna Park ofconsid- movements are by no means unusual in
erable interest. Only through community butterflies asconditionschange, with some
awareness can such events be effectively species surviving continuouslyin a suiteof
documented and publicised. ECB conser- habitat patches, only some ofwhich are
vation is broadly overseen by a statewide occupiedatanytime, onasiteandwiththe
management group, with representation population sustained through a series of
from all range areas, state and municipal ‘colonisation-extinction-recolonisation’
agencies, and independent scientists, and
Fig. 3. The Eltham Copper Butterfly sites at Greensborough (1) and Eltham (2-6). The
Greensborough site is Yandell's Reserve, whilethe Eltham sites arethe Pauline TonerReserve (2),
the Westerncolony(3),theEasterncolony(4),the formerYarraValleyWaterland(5)and Hohne's
Hill(6).ThePittStReserveisonthesouthsideofPittStadjacenttothePaulineTonerReserve.
Vol. 124 (4) 2007 239
Invertebrate ConservationIssue
sequences across the landscape: part ofthe small areas and by urbanisation on essen-
slaytsitoen'msctornuscttiutrue.tinTghiaspmoassyibblee p'amrettiacuploaprul-y triuanlolfyf,isorluabtbeidshpopduulmaptiionngs,. wFaecetdorsinsvuascihoans
pronounced at Kiata/Salisbury, where the vandalism and general human traffic con-
Bursuria is very patchy on the sites, and tribute severally and collectively to habitat
movement between food plant patches degradation. Issuesofhuman concernfrom
(which are also a nectar source for adults) neighbouring residents also occur. For
isnecessary. example, accumulation offuel on the sites
In contrast, this process and population is perceived to increase the risks ofwild-
structure is thwarted on small sites. At fire to property. Many of these anthro-
Eltham. for example, there seems little, if pogenic effects are ofminimal importance
any. chance that butterflies can disperse on the more rural sites, in the context of
between the major site-based colonies, sustaining critical resources for the butter-
because the intervening terrain is highly fly. At Kiata, encroachment ofagricultural
altered to comprise houses and roads, so crops on to ECB habitat, and rabbit/hare
that all population processes have to occur grazing on Biirsaria are concerns. At
(and be sustained) within the confines of Castlemaine, activities such as trail-bike
single small sites, each ofwhich harbours riding have caused some concerns
at
adiscretepopulation. Thereiscurrently lit- Kalimna Park, in addition toweedinvasion
tle or no opportunity for genetic exchange and rabbitgrazing.
between those demographic units. Mark- Differences in site scale are linked with
release-recapture studies have not shown threat intensity. Almost inevitably, details
exchange ofindividuals between colonies. ofthe management needed are site-specif-
However, enhancement ofhabitat connec- ic, but the additional implication is thaton
tivity through carefully planned revegeta- very small sites, the butterfly is ‘conserva-
tion of roadside verges and residential tion dependent’ and that continuing man-
properties with the host plant, to allow for agementon each site isnecessaryandmust
'corridors' for the butterfly, may thereby be assured. Longterm agencycommitment
facilitate movement between habitatpatch- is therefore needed, and can be very diffi-
es. Undiscovered colonies may still occur, cult to obtain, despite considerable good-
even in the highly urbanised Eltham loca- will. Elsewhere, more sporadic manage-
tlioorn,thwehEerCeBahdadvietiobneaelndieddeintciaftieedd roevseerrvtehse mleesnstitnotaedndsrievses(pia.ret.iccuhleaarptehrre)atbsumtavyiabbelea
last five years. These include a block at option. Again, the interest of individual
Pitt Street at the top end of the Pauline people is a vital component ofensuring
Toner Reserve (Yen 2002) and the Yarra effective monitoring and management of
Valley Water property that abuts the thesesites. Atall sites, monitoringisafun-
Eastern Colony. It may be possible to damental component ofassessing manage-
'link' some ofthese Eltham reserves with ment need by tracking changes as they
appropriate planting ofBiirsaria in private occur and adapting management accord-
gardens between them. Management must ingly. Forexample, grazingofBiirsariahy
thus focus on sustaining critical resources haresat Kiata ledtotheerection offencing
in exploitable form in the same small to protect critical bushes. Vehicular tracks
areas, rather than in a wider landscape at Kalimna Park have been blocked orren-
mosaic, and must therefore counternatural dered inaccessibletocasual visitors.
processes (such as succession) to a greater Continuing management needs around
extentthanon largersites. Eltham include:
The underlying ecological differences (a) control of exotic weeds and main-
between the largerand smallersites dictate tenanceorenhancementofBiirsaria\
in part the nature of threats and the (b) maintenance ofconditions suitable for
emphasis of alleviative management. Notonciis\
Management is necessarily more intensive (c) prevention ofovershading, forexample
on small sites, to counter ecological bycanopyclosure;
processes and the more proximal anthro- (d) removal of fallen debris, as a fuel
pogenic threats wroughtby edge effects on reduction measure;
240 The Victorian Naturalist
Invertebrate ConservationIssue
(e) minimising inappropriate inputs, such Timing and intensity ofall management
as diverted water runoff, into the is informed by monitoring ofthe butterfly,
reserves; both as adults and caterpillars. Intensive
(f) undertaking any such measures in monitoring was initiated by Van Praagh
concert wdth conservation needed for (1996), augmented by some student pro-
othersignificantspecies^on eachsite; jects on coppicing ofBursaria spinosa by
(g) continuing to foster interest of local the Eltham Copper butterfly (Carroll et al.
people in the conservation process, 1998) and observations on larval feeding
through volunteer programmes and b1e99h9a)viour as well as germination of
education. Bursaria spinosa seeds (O’Sullivan et al.
Other management measures include Recentstudieson caterpillarmobil-
.
coppicingofoldBursariatopromote fresh ity, feeding behaviour and frequency, and
growth, enhancementofBursariabyplant- adult dispersal involving marking individ-
ing (using plants from local seed stocks), uals and tracking them in their environ-
and hand removal of weeds (particularly ments (Canzano, unpubl. data) are aiding
on siteswhererareorchids andotherplants refinement ofthe monitoring process, and
occur). The lastis importanton afew sites, may help to reduce some ofthe current
on which even moderate human trampling uncertainties over interpretations ofinter-
pressure or less sensitive control measures generational changes in numbers (Johnson
suchasherbicideusecouldproveharmful. 2002) and increase predictive capability.
Some such management has been highly Such recent biological insights will feed
experimental, even risky, as with the deci- directly into a refined plan for conserva-
sion to bum two major butterfly sites (the tion ofthe Eltham Copper, in which the
'Western Colony’ and 'Eastern Colony’)at biological differences and opportunities in
Eltham to ‘rejuvenate’ them and help the different sectors of its range will be
reduce canopy closure and weed popula- treatedboth individually and in concert for
tions. Such drastic intervention was con- a more holistic overview ofmanagement
sidered necessary as the major avenue to for its future. Without them, or without
counter continuing decline in site quality, appreciating the influences ofthe different
and in site capacity to host the butterfly sites on the butterfly’s potential for sur-
(New et at. 2000). A ‘hot fire’ in April vival, management may be severely
1998, a time when the caterpillars were impoverished through inadequate ecologi-
already present and moderately grown, cal focus. A prime purpose ofthe Eltham
involved numerous people and fire brigade Copper Butterfly Working Group is to
units, and also involved considerable risk address such issues, and to hone manage-
to the butterfly population, but was ment so that the best possible options are
endorsed on the grounds that should the understoodandavailable, bothnow and for
site become inhospitable that population application in the future, perhaps to addi-
was in any case doomed. Needs for plan- tional populations should they be discov-
ning the burn were for it to be as hot as ered or founded deliberately. Whilst these
possible (to open canopy and destroy exot- notes have been confined to field popula-
ic weed seedbanks), as late in the summer tions, a captive breeding programme for
as possible (to allow caterpillars maximum the butterfly is also contemplated by the
feeding time before their food supply was Melbourne Zoo, as an investment in the
lost), during the day (when caterpillars are future of this notable Victorian insect.
underground so not exposed directly to the Further research on the ECB is necessary
flames and heat), undertaken only under because ofthe need for information on the
‘safe’ weather conditions, and to extend biology and ecology ofNotonciis ants in
over much of the site, except for small relation to the ECB, the genetics of the
damped down areas in which caterpillars ECB, and ^CB-Bursaria interactions to
were particularly abundant. Most caterpil- assistitsconservation.
lars indeed survived, and the ensuing adult
Acknowledgements
population was not conspicuously dimin-
ished. WThoirskipanpgerGrisouwrpitatenndotnhebeahuatlhfoorfstwhieshECtBo
acknowledge the input ofthe members ofthis
VoL 124 (4) 2007 241
Invertebrate Conservation Issue
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researchers, whose enthusiasm and hard work Publishing:Melbourne)
mphoaapsnuacloagntetimroienbsnuttiendofVtiotchttoehreiEaslu.tcchMeaiscmslhlaCielolpmpoBenriratboByru,itntDgearvafinlddy CarUHMrnoeorilltvlibecrouEsul,itrtuCnyrleaeol'afsrRMyeebslSueb,taotGruecorrhdnfdelR.ayerpdaorntBd,amBnoudrtnhMluecymobCmoymIIulKnm.i,Mt-QiOcfi,
CforrosthbeyiraenadrlyPabtiroilcokgiVcaalugrehsaenarcahreancdomesmteabnldisehd- CrtohsebyElDthFam(1C98o7p)peTrheBuntatteiroinlayl{cPoanrsaelruvcaitaiopnnsotadtuhslm
pEAiTttLmroneneheCrevridanBiomsgentnlehrkgvmnWssoeotAoopfdntnhrriosektoithtnfriBgoeoaennrrrmfvigaCfaenhfmonrigoGonmslarrfseeagoweyniiuonrtdanpiVrthvg.teaakriatnaeltTliaalvhlhssoPeayesVnrrtieaEcihcssaloMeotsugt-auomphchfsrnepioairnofaosmartotmgrnrtdaeroPliesomfnaeinsfreaatetakednhrgtpssiev,taienesnrgmmstSgaPotenllaanegtonannivehnntdde-er.g EnP(TCblDRdroLueeeyenocehcrplsicpahsaaedievnbrhradeiiyvtodocamCpuiaItIretrnlniDonesgostrotnsR(bfia,1eyto:o9pPu)Fff9otoaL6errrCt()yethaoLsceenlfStapsuSosoReierecondamrrivoniiveaEpaeddantslptaaveLviseairNSrpo)naroeoond:ccod.,saitint:esLsm8FtycE1eoMoyculrenfasetloe(tsbthnfDathloaielesuuVmdpcira,abiacneirRtdne)oeiVoad).lsirmeociCeLaptAarnroaynoicrn1shlaid0bniao)vdf
(aDuulaDtaverhi,opdraiwrtVeiteemnswenoi,nsutglPredatteelrfoiufkJleolhytnoasScoutknshntaoaanwnikldneaAdGblglieaeldnni.ntWyIRenubpdsatoraetlinrpcd.h- JoUMlHhnueoncitnsivhdeosoarnds(TisCtEhylaet(snoh2idfa0smML0,ea2lrC)DbvoeoapIlupnprvaeBnerriesot.tlBmioueggttyane’ttrifool/oynP)fa.roafFUlonitrpihuceebislatMio.pysSnrhcioeidtdeionsBccrSuescs I
(SEPhnaivrirkresonCVmoieucnnttoc)ri,ila)D).a,vJiPdoantAarvitcehkronyVaManiudlglCehraanm(Ni(BelCailrtudymsbeiolklf NeLthwyecTamRea,nniaVdgaenbmuPetrtneatrafgolhyf,BhaPDbairataantlduqYcueianalitpAyyLrion(d2ia0sn0c0Au)ussFtilrrauelciaiandnda
Banyule) and Jenni Thomas (formerly NC Crosby,theElthamCopper. Metamorphosis11,154.
oacCofnMndAtexr)Rpi.eborubttDeiearsdvtei.todAMntChadeaenmrEyesCrovBononlpu(rn(MotDeegSlerEbra)som;umhrePanaveitenriZtdchoekeodi)riHcoaaarntleaesandos O’aaTStnhuidleolnmiraevotnafunargMnCee,olmfbeTonthuthoremonfLpee’sppsloiandnLotepsJtp,eaiarndandondpsht:aWebhriTitahatnteeslceofasomwtrmabutAlnhieis(thr1iem9cee9rn9set)-
theirtimeandenthusiasmtomonitoringboththe Horticultural Research Report, BurnleyCollege,The
hlaarbviatlatanmdanaadguletmestnatgewsoorfksthtehEroCuBg,hawseewedllanads VaUnniPvrearasigthyBoDfM(e1l9b9o6u)rnAed.ultandLarvalCountsofthe
rKMuiaabntbyaisthFhlaornrekamsoRtveoaslMearavrneyd;ArrGegeapollfiafnatnHidangntnhheoonsFtriaepnlndadnsttsho.ef daERnealdptoChErrantomvsiNbCroyoo..pnpm11ee49rn49t.3B:u-(t1MDt9eee9lrp5fbal.oryu,tFrmlnPeoaenrr)taaloaufncdiNaaFtpauyurranoladiRTseecscuohsunrilccucaeils-
FWraiyenndesKoifnrKaadleimannadPtahrek;FrAinenndasRoifchtthaeriEkl;thaanmd VaCuogphpaenrPJBu(t1t9e8r8f)lyM{aPnaargaelmuecnitaPplvarnodfiosrctuhseEllutchiadma
CopperButterfiy. Crosby) (Lepidoptera: Lycaenidk). ArthurRylah
Institute for Environmental Research, Conservation
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PLayrcaahetnciidaaepy)r.ocUJscouusrnlaulcidaoCfrostbhye (LAeupsidtorpatleiraan: YeMnelAboLur(n2e0)02) The Status ofthe Eltham Copper
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EDilstthraimbutCioopnpearndBurtatnegrfelyrePdaurcatliuonciainpVvircotdoirsicausoflutchie- CReoploorntietsotahte2S2hi0rePiotftNSitlrleuemtb.ikE.ltham. Unpublished
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AduulsltrcaolipapnerBuPtatreraflluiceisa(pMyornoodgirscaupsh.sIonfBAiusotlroaglyiaonf Received29March2007:accepted31Mav2007
One hundred and One Years Ago
LmhMuaarsdmtFbp.ehnGea.mnvAae.inrgBuoiatttisrlnipaanrntresod,seiwnmthtasidipcnoehcseishtoeiitomhnweaaldsroerrpmemlacoarercnketesldytoihntnaantikthetsenwpelrfnaertrsovyemaneytaeaaprrnoesdsd,itpgaienuordnfm.etcvOhteevrrbeeearfenotdtrlaweehsetnphotoefyslttlahaaretrvvaGKaeoeelowdaf.entndhTehpBeeebreefpteeoltcelst,et
UbeKetlCeosckwcehraefeorb,taAinnoepdl,ogtnheatlhairivsa.esrpe.seTmhbelipnegrfveecrtybceleotsleelsywtehroesealulsuoafllsymarlelgasridzee,dbaustthveerlyarhviagehloyf
From The VictorianNaturalist.XXIIIp 116,October4, 1906
242
The Victorian Naturalist