Amphibians of Gibraltar Range

2006·3.5 MB·English

by  Michael Mahony

Amphibians of the Gibraltar Range
Michael Mahony
NSW
School ofEnvironmental andLife Sciences, Newcastle University, University Drive, Callaghan 2308
Mahony, M. (2006).Amphibians ofGibraltarRange.Proceedings oftheLinneanSocietyofNewSouth
Wales. m,S3-9l.
The GibraltarRange supports a relatively high diversity ofamphibians andthirty frog species, with equal
numbers of tree frogs (Hylidae) and ground frogs (Myobatrachidae) having been recorded there. It is
postulatedthatthe geologicalhistory ofthe GreatDividingRange andthe ruggedlandforms on its eastern
edge, known as the Great Escarpment, provides the underlying explanation for the amphibian diversity
present. Among the amphibians four major biogeography groups are recognized based on distribution
and association with major vegetation communities. The largest group consists of 15 species that have
widedistributionswithin andbeyondtherange andoccurin severalvegetationcommunities, andonlyone
member is categorized as threatened. The second group consists of 12 species and is associated with wet
foresthabitatsoftheescarpmentandcoastalbelt,withfourthreatenedspecies. Thethirdgroupisrestricted
to rainforest habitats and consists ofthree species ofground frog, two ofwhich are threatened. The final
group is associated with the drier open forests and grasslands ofthe tablelands and western slopes and
consistsoffourspecies,threeofwhicharethreatened.Nofrogisendemictotherange,althoughoneground
frog,Philoriapughi, is foundonlyintherange andthe nearbyNewEnglandRange andTimbarraPlateau.
This species andAssa darlingtoni, another ground frog, are closely associated with the warm temperate
rainforestthatisrestrictedtothehigheraltitudesontheGibraltarRange,andtheirdistributionisconsidered
to be relictual. Their broader distribution is within isolated montane rainforest that occurs on the higher
peaks ofthe Great Escarpment and coastal ranges. Among the frogs ofthe GibraltarRange, 11 ofthe 30
species are categorized as threatened, eight ofwhich are associated with sfream habitats. This is despite
the largeareas ofundisturbednatural habitatpresentontherange. In contrast species associatedwithpond
habitats are lessrepresentedinthis group.
Manuscriptreceived4 May2005, acceptedforpublication7 December2005.
KEYWORDS:
amphibians, GibraltarRange, GreatDividingRange, GreatEscarpment, Hylidae, mesic
forests, Myobafrachidae, rainforests.
INTRODUCTION
The Gibraltar Range occurs on the eastern boimdary
of the Great Dividing Range. The Great Dividing
An investigation of the biogeography of the Range is the dominant landform feature of the east
amphibian fauna ofthe Gibraltar Range in northeast coast ofAustralia, and running along its eastern edge
NewSouthWaleswasundertakentoshedlightontheir is the Great Escarpment. Oilier (1982) postulated
origins, relationshipsandthe implications ofthesefor that the escarpment originated by scarp retreat from
conservationmanagement.Thestudyofbiogeography a new continental edge ofeasternAustralia about 80
is fundamentally concerned with the documentation million years ago. From a biogeographic perspective
andinterpretationofthedistributionoffloraandfauna this results in two principle axes; the first is in the
and their interrelationship. Uncovering origins and north-south direction of the Great Divide and the
dispersal routes of organisms largely depends upon associatedGreatEscarpmentthat extends inthe order
the degree of resolution of distributional data and ofhundreds ofkilometres, the second is in the east-
robust phylogenetic reconstructions of evolutionary westdirection fromcoasttotablelandsthatextends in
relationships (Tyler et al. 1974). the tens ofkilometres.
Anunderstandingofthecompositionandancestry ThegeologichistoryoftheGibraltarRangeandits
of the amphibian faima of the Gibraltar Range is landforms are significantfactors inourunderstanding
underpiimed by interpretations of the geological of the composition and ancestry of the amphibian
history ofthe landforms ofthe range and its climate. fauna. Thehighermountainsonthe GreatEscarpment
AMPHIBIANS OF THE GIBRALTAR RANGE
experience a climate of moderate temperatures and forests that have been associated with the Great
high rainfall and support mesic forest vegetation Divide for tens ofmillions ofyears, and the second
communities at mid to high altitudes. These forests is the extentofdiversificationthathas occurred asthe
contain ancestral elements ofwet forest communities Great Divide has been eroded away and as climate
thatwereoncemorewidespread,particularlyalongthe has changed.
Great Divide, and have contracted as the Australian The objective of this paper is to provide an
climate has dried (Nix 1991). overview of the diversity of frogs in the major
In the north-south axis the higher mountains vegetation communities ofthe GibraltarRange along
along the Great Divide provide refiiges for the flora withaninterpretationofthecompositionandancestry
andfaunaadaptedto these mesichabitats andprovide ofthe amphibian fauna. Where appropriate, details of
a view oftheir evolutionary history. The frog species habitat use and conservation status will be discussed
found in the mesic forest habitats are postulated to along with the implications formanagement.
reflect a long evolutionary relationship between
the flora and fauna. In the north-south axis the
Gibraltar Range is one ofmany ranges that form the MATERIALSAND METHODS
relatively continuous Great Divide. While it may be
relatively continuous as a major landform feature it To compile a list of the amphibian species
has considerable variation in altitude and ruggedness of the Gibraltar Range a number of sources were
along its considerable length. The Gibraltar Range consulted. A primary species list was assembled by
is one of the higher ranges along the length of the consulting the records of the Australian Museum,
Great Divide with its highestpeaks being above 1400 Queensland Museum, Victorian Museum and South
metresinaltitude,andalongwitharuggedtopography Australian Museum. To these were added the records
and complex underlying geology (Barnes et al. 1995) in the Wildlife Atlas of New South Wales (NSW
result in a complex mosaic distribution ofrainforests DEC, NPWS, accessed April 2005). A selected
and wet sclerophyll forests. literature search was conducted that included large
Intheeast-westaxistheGibraltarRangestandsat and comprehensive surveys such as the North East
thejunction oftwo major geomorphic provinces, the Forest Biodiversity Survey (NSW NPWS 1994) and
tablelands to the west and the coastal belt to the east. Fauna Surveys for Forestry Enviroimiental Impact
Inthis axisthe formationofthe GreatEscarpmentand Statements (Smith et al. 1994; State Forest NSW,
the mountain ranges, river valleys and coastal plains 1995). Lastly, records from targeted surveys for
associatedwith it, provide a diverse topography from taxonomic studies and from a long-term monitoring
low to high altitude. On its western side the Gibraltar site in Washpool National Park were included
Range has upland areas of low relief with gently (Knowles et al. 2004; Donnellan et al. 2002, 2004;
flowing streams and tableland swamps. On the east Mahony unpubl. data). In addition, information on
is a steep escarpment with rapidly flowing sfreams the vegetation communities and habitats occupiedby
and deep gorges, and to the northeast is an area of each species was collated.
moderate to high relief with rapid flowing streams. Based on distribution records and association
To the south and east the scarp is clearly defined by with majorvegetation communities frog species were
the Marm River and its smaller tributaries, while to assigned to one of four categories, 1) widespread
the northeast the range is almost cut offby the Rocky occurrence across the region in all major vegetation
(Timbarra) River to form an isolated plateau. This communities, 2) eucalypt-dominated forest
river runs in a northerly direction along the line of communities of the escarpment and coast belt, 3)
Demon Fault that separates the Gibraltar Range from rainforest specialists, and 4) woodlands, dry forests
the tablelands to the west. and grasslands of the tablelands. Within these
While the Gondwanan origin and relationship of categories the frogs were subdivided on the basis of
Australia's two major frog families, the Hylidae (tree primary breeding habitat.
frogs) and Myobatrachidae (ground frogs) is well Conservation status of species was based on
accepted, the geographic context of the evolution listings in the New South Wales ThreatenedSpecies
and diversification of the Australian frog fauna Conservation Act 1995 (NSW TSC Act 1995)
remains a matter ofconsiderable debate (Tyler 1979; supported by a recent assessment of Australian
Roberts 1998). Two major features oftheir evolution amphibians that applied the International Union
can be investigated by studies of the fauna of the for the Conservation of Nature (lUCN) categories
Great Divide. The first is evidence of the ancestral (GlobalAmphibianAssessment 2004).
composition of the amphibian fauna of the mesic
84 Proc. Linn. Soc. N.S.W., 127, 2006
MAHONY
M.
RESULTS altitude inWashpoolNationalPark(NP) andEwingar
State Forest (SF).
A
total of30 frog species has beenrecordedfrom
the GibraltarRange and a ftirther four are considered Frogs offorest communities oftlie escarpment
likely to occurthere (Table 1). Equal numbers oftree and coastal belt
frogs (Hylidae) and ground frogs (Myobatrachidae) The second largest group is associated with
are found. All hylids present are members of the eucalypt-dominated forest vegetation communities
genus Litoria, while there are eight genera of of the escarpment and coastal belt. Twelve species
myobafrachids. Despite the relatively high species are placed in this group, eight tree frogs and four
diversity many species are represented by a small ground frogs (Table 1). As might be expected due
number of location records, and for several species to the rugged topography of the escarpment the
by a single location record. As a result the regional majority ofthese species are associated with stream
distribution, abundance and habitat associations habitats. Six species, three tree frogs and three
of many species are incomplete. Fauna surveys ground frogs, breed in streams and have tadpoles
conducted for the North East Forest Biodiversity adapted to sfream habitats. Among these, three
Study (NSW NPWS 1994) and Forestry EISs (SF species, Litoria subglandulosa, L. piperata and
NSW 1995) provide the most detailed picture ofthe Mixophyes balbus(Fig. lb), are resfricted to higher
distribution and abundance of species. Discoveries altitudes on the escarpment. Vegetation community
made during surveys in the last two decades indicate is not the major factor determining their distribution;
that significant disfributional records, and even new they occur in sfreams within heath, dry forest, wet
species, may be found there (Dormellan et al. 2002; forest and rainforest communities. One stream frog,
Knowles et al. 2004). Mixophyes iteratus (Fig. Ic), is found only at low
to moderate altitudes and is always associated with
Frogs with a widespread distribution rainforest or wet forest habitats. The remaining two
Division ofthe frog faunaintomajordistribution species {L. barringtonensis and M.fasciolatus) occur
patternsandbroadvegetationcommunityassociations across the range ofaltitudes but always in wet forest
reveals that the largest group numerically is species communities.
that have a widespread distribution and that occur Five species in this group breed in ponds and
in several vegetation communities. Fifteen species swamps, and two ofthese often breed in ephemeral
are placed in this group, seven tree frogs and eight situations (Table 1). Forthree ofthe species included
ground frogs (Table 1). Most of these frogs have in this group (Z,. brevipalmata, L. revelata and L.
extensive distributions in south-eastern Ausfralia tyleri) there are no confirmed records inthe Gibraltar
(see distribution maps in Cogger 2002 and Robinson Range. They are included here because they occur in
2002). This is not to say that they are necessarily wet forest habitats to the north, south and east ofthe
habitat generalists. Subdivision of these species by GibraltarRangeanditisconsideredpossiblethatthey
preferred breeding habitat shows that the majority, occur in the range. Ifthese species do occur they are
14 of the 15, make use of ponds or swamps, four not abimdant because they have not been detected in
use both ponds and streams and could be considered systematic surveys (NSW NPWS 1994; Smith et al.
NSW
to be generalists in respect of breeding habitat, and 1994; State Forests 1995) or targeted searches
only one is a stream specialist. Two species that use (Mahony unpubl.). Litoria brevipalmata is often
ponds show a preference for ephemeral ponds and a difficult to detect in field surveys because adults are
third {Crinia signifera) makes use of a wide range active at breeding sites on only one or two evenings
ofwater bodies from small ephemeral pools to large ofthe year. Records ofZ,. revelata may be absent for
swamps, indeed the only habitat it is not found in is a different reason. This species was overlooked in
fastflowing streams. This species occurs in disturbed the past and until recently it was not distinguished
sites and therefore is common where human activity from Litoria verreauxi, a close relative. Field guides
opens ormodifies habitats. do not indicate that L. revelata is found south ofthe
Only one species in this group is categorized as Border Ranges region, which are approximately 120
threatened.TheNewEnglandTablelandpopulationof kilometres to the north-east ofthe Gibraltar Ranges,
Adelotusbrevisislistedasan"endangeredpopulation" yet recent field studies (Price 2004) indicate that it
under the NSW TSC Act. No recent records of this occurs in a series ofapparently isolated populations
species were found at high altitudes in the Gibraltar along the escarpment and coastal ranges as far south
Range,but severalpopulations areknown from lower astheSydneyBasin.Targetedsearchesforthisspecies
have been conducted in the Washpool National Park
Proc. Linn. Soc. N.S.W., 127, 2006 85
AMPHIBIANS OF THE GIBRALTAR RANGE
^^^^^9
^^^^^^^^^^_
lypicalbreedinglocation
Associationwith majorvegetation community
Pond
Conser- Terrestrial
Stream and/or Ephemeral
Species scientific andcommonname vation breeding swamp pool eggsand
status embryonic
(lentic) breeding breeding
stage.
Gotic)
Widespread occurring J^H^^HHIF
^^^^^^^B
in manyvegetation
^^^^^V
communities from
rainforestto grassland
Litoriacaerulea GreenTree Frog X
X X
L. dentata BleatingTreeFrog
L.fallax DwarfTreeFrog X
L. latopalmata Broad-palmedFrog X
L.peronii Peron's Tree Frog X
L. verreauxi WhistlingTree Frog X
L. wilcoxi RockyRiverFrog X
Adelotus brevis TuskedFrog EP X X
X X X
Criniasignifera Eastern Froglet
X X
Limnodynastes dumerillii Banjo Frog
L. ornatus Ornate BurrowingFrog X X X
L.peronii Striped MarshFrog X
X X
L. tasmaniensis Spotted Grass Frog
^B
Uperoleiafusca DuskyToadlet X
U. laevigata SmoothToadlet ^^B X
Escarpment and coastal
belt.Wet forests excluding
rainforest specialists
X
Litoria barringtonensis BarringtonTree Frog
L. brevipalmata* Green-thighedFrog V X X
L. chloris Red-eyedFrog X X
X
L. gracilenta DaintyTree Frog
L.piperata PepperedFrog E X
X
L. revelata* RevealedFrog
V X
L. subglandulosa GlandularTree Frog
X
L. tyleri* Tyler's TreeFrog
Mixophyes balbus StutteringFrog E X
M.fasciolatus GreatBarredFrog X
M. iteratus GiantBarredRiverFrog E X
Pseudophrynecoriacae Red-backedToadlet X
Restricted to high altitude.
Rainforest specialists
Assadarlingtoni Hip-pocketFrog V X
Lechriodusfletecheri SandpaperFrog X
Philoriapughi Mountain MistFrog V X
Tablelands and western
species.Woodlands, dry
forest and grasslands
Litoria booroolongensis Booroolong Frog E X X
L. castanea* Yellow-spottedBell Frog E X
X
Criniaparinsignifera Beeping Froglet
Pseudophryne bibroni BrownToadlet EP X X
Total 13 21 6 4
86 Proc. Linn. Soc. N.S.W., 127, 2006
MAHONY
M.
without success. The final species, L. tyleri, is readily Frogs ofthewoodlands, dryforests and grasslands
distinguished and the lack of records may indicate ofthe tablelands
that it does not occur in the Gibraltar Range. Another relatively small group are the frogs that
Five species in this group are classed as are associated with the vegetation communities of
threatened, andeachofthesebreedinstreamhabitats. the tablelands and western slopes. Four species, two
Incontrast, nopond-breeding species inthis grouping tree frogs (Litoria booroolongensis and L. castanea)
is threatened. One ofthe two stream-breeding species and two ground frogs {Crinia parinsignifera and
that is not threatened, Mixophyesfasciolatus, breeds Pseudophyrne bibroni) are placed in this group
inboth ponds and streams. (Table 1). The group may be even smaller because
there is no direct evidence that the two tree frogs
Frogs that are found only in rainforest habitats {Litoria booroolongensis and L. castanea) occur in
The group with the narrowest distribution is the the Gibraltar Range. They are included here because
rainforest specialists, with only three species, all of of proximity of records on the tablelands and the
which are ground frogs. The absence of tree fi-ogs presence ofsuitable habitat inthe range. Both species
from this group is not unexpected, given that there is have disappeared from the New England Tableland
no tree fi"og that is restricted to rainforest vegetation (Hines et. al. 1999; Mahony 1999) and it may be
communities of the Great Escarpment in NSW and that we will never know whether they occurred on
south-east Queensland. It is not until the rainforests the Gibraltar Range. Litoria boorolongensis had an
offar north Queensland that we encounter tree fi^ogs extensive distribution on the New EnglandTableland
that are restricted to rainforest habitats. andonthewesternslopessouthtotheAustralianAlps,
Two ofthe ground frogs, Assa darlingtoni (Fig. and suitable habitat in the Gibraltar Range occurs
la) and Philoria pughi (Fig. Id) reflect refugial alongtheupperreaches oftheMannRiverandRocky
distributions. They occur only at higher altitudes in (Timbarra) River.Litoriacastaneahad a farnarrower
warm temperate rainforest or deeper gullies with distribution thatwas centred on tablelandhabitats. Its
subtropical rainforest. In the Gibraltar Range the preferred habitat was tableland swamps and lagoons
distribution of Assa is limited to a relatively small and the upper altitudes in the southern areas of the
area of high altitude warm temperate rainforest GibraltarRange contain significanttableland swamps
(above 1000 m) and Philoria pughi has a slightly inundisturbed condition.
wider distribution in warm temperate and subtropical Of the two ground frogs in this group, one, P.
rainforestfrommidto high altitudes (800 to 1000 m). bibroni, has also disappeared from the tablelands
These vegetation communities are relicts of former (Mahony unpubl. data). There are no records ofthis
morewidespreadvegetationcommunities. Theyattest species from the Gibraltar Range, but once again
to apast when the climate was wetter and milder and its was formerly widespread across the tablelands
when their distribution was more continuous along (Heatwole et al. 1995). The remaining species in this
the great escarpment. The last member ofthis group, group, C. parinsignifera, is common and widespread
Lechriodus fletcheri, is found in rainforest from being found in ponds and swamps in open vegetation
low to high altitude and thus its distribution is more communities, and is often associated with disturbed
extensive. areas. The limit of the distribution of the two tree
fi"Ogs (L. booroolongensis and L. castanea) is at the
upper orwestern edge ofthe escarpment on the other
Table 1. LEFT hand the two ground frogs are also distributed to the
east on the coastal plain, but they are not found inthe
Major habitat association, breeding location and wet forest habitats ofthe escarpment. Pseudophyrne
conservation status of the frogs of the Gibraltar bibroni is replaced by a congener P. coriacae in the
Range. Conservation status is based on lUCN cat- wet forests ofthe escarpment, and C. parinsignifera
egories (Stuart et al. 2004). For a small number shows a preference for open habitats.
of species there are no records for the Gibral- Each member of this group has a distinct
tar Range; they are included because popula- breeding biology and behaviour and there is no
tions are known in forested habitats to the north, apparent link between these features and those that
south and east and it is likely that they occur in have disappeared. Litoria booroolongensis breeds in
the Gibraltar Range. They are identified by an flowing streams, L. castanea in swamps and pools,
asterisk. An ephemeral water body is defined as sometimes in large still pools on streams, and P.
a non-perennial; it can be a pool that lasts for a bibroni lays its eggs in terrestrial sites near swamps
matter of days or weeks or up to several months. and pools.
Proc. Linn. Soc. N.S.W., 127, 2006 87
AMPHIBIANS OF THE GIBRALTAR RANGE
a
^\ "
„
*^*'-
^
( ' ";~ i.-fS^^-^i^': i -..-^- _V'
^%^
<
.11h^, " ^^^
. .
Figure 1. a) Adult male Assa darlingtoni surrounded by hatching embryos prior to their entering into
his lateral pouches where they will undergo the tadpole stage of their life cycle. This terrestrial frog
is found only in warm temperate rainforests at high altitude in the Gibraltar Range, b) Adult male
Mixophyes balbus, an endangered stream-breeding species that occurs in high altitude streams of the
Gibraltar Range, c) A pair of Mixophyes iteratus in embrace prior to egg deposition. This vulnerable
species is found in stream habitats at low altitude in the Gibraltar Range, d) A male Philoria pughi
within its terrestrial nest chamber that has been exposed by lifting away a covering ofleaves. A clutch
of embryos in early stages of development and still within their egg capsules can be seen beneath
the male. After the embryos hatch, the tadpoles remain in the nest and leave after metamorphosis.
No frog species is endemic to the Gibraltar ancient geomorphic regions, the tablelands to the
Range. Philoriapughihas the narrowest distribution, west and the coastal plain to the east, and provides
it is known only from the Gibraltar Range, and the habitats for species that have evolved in these
New England Range and Timbarra Plateau to the regions. These differences are reflected in the aquatic
north. Two others, Assa darlingtoni and Lechriodus habitats that are present, from tableland swamps with
fletcheri, occupy refiigial mesic forest habitats, and slow flowing streams to fast flowing streams on the
their populations in the Gibraltar Range are isolated escarpment. The rugged topography ofthe region, its
from other restricted populations along the Great altitudinal range and climate result in the presence of
Escarpment. several major vegetation communities.
All of the frogs found on the Gibraltar Range
belong to two families that have a long evolutionary
DISCUSSION relationship with the Ausfralian continent; the tree
frogs of the family Hylidae and the ground frogs
The high diversity of amphibians found in the of the family Myobafrachidae. These families are
GibraltarRange canbe explainedbyacombinationof recognized as being of Gondwana origin (Tyler
factors; the antiquityoftheGreatDividingRange, the 1979); they are old endemics. Molecular genetic
abrupt change in altitude and the rugged landscape evidence indicates that the ancesfral tree and ground
ofthe Great Escarpment, and the consequent climate frogs were already well differentiated at the time
differences. The range stands at the junction of two Australia separated from Antarctica some 52 million
88 Proc. Linn. Soc. N.S.W., 127, 2006
MAHONY
M.
years ago (Daugherty and Maxson 1982; Hutchinson in the number ofamphibians present.
and Maxson 1988). Apart from the introduced cane The significance of the geomorphic processes
toad (family Bufonidae) Australia has members of that have shaped the Great Escarpment in relation to
two other families of frog, the Michrohylidae and the evolution ofits terrestrial fauna is evident in the
Ranidae. Members of these families are considered Gibraltar Range. With respect to the north-south axis
to have arrived inAustralia inmore recent geological the Gibraltar Range is an isolated area of uplands.
time, when theAustralian continent came into closer Scarp retreat created firstly steep gorges and then
contact with south-east Asia (Tyler 1979), and their wider valleys, as these valleys widened and their
members are foundonly inrainforesthabitats innorth headwaters refreated further west the higher altitude
Queensland and theNorthern Territory. ranges ofthe Great Divide and their fauna and flora
Several genera and species groups that have were isolated (Oilier 1982). It is postulated that
a long association with the mesic forest habitats of dispersal was limited where large valleys with drier
the Great Divide and escarpment can be identified vegetation communities dissected the ranges. For
in the Gibraltar Range. Two examples are briefly example, in the Gibraltar Range isolated populations
considered, one from each of the major families, to of a small number of rainforest frogs are found at
illustrate this point. The five species of Mixophyes higheraltitudes{Assadarlingtoni, Philoriapughi, and
are found only in wet forest habitats along the Lechriodusfletcheri)inmesicrainforestcommunities.
Great Divide and escarpment from east Gippsland In addition to the isolation resulting from landscape
in Victoria to the Atherton Tablelands in far north barriers are the barriers that were created as climate
Queensland, with a fiirther species found in montane changed. In the past the climate was warmer and
rainforest in Papua New Guinea (Dormellan et al. wetter and the mesic vegetation more widespread on
1990). Phylogenetic studies (Heyer and Leim 1996; theGreatDivide(Nix 1991),providinganopportunity
Kluge and Farris 1976) place this genus in a basal for species adapted to the mesic forest habitats to
position among the myobafrachids and their current disperse. From the perspective of the amphibian
distribution and habitat preferences sfrongly suggest faunatheperiodor extent ofisolation ofthe Gibraltar
they have had a long association with the wet forests Range has not been extensive because only one frog,
ofthe Great Divide and escarpment. Among the free Philoria pughi can be described as endemic to the
frogs members of the Litoria citropa species group Gibraltar and the nearbyNew England Ranges.
(Tyler and Davies 1978) are closely associated with From the perspective of the evolution of its
the wet forests of the Great Divide and escarpment amphibian fauna it is perhaps more appropriate to
from southern Victoria to mid east Queensland viewthe GibraltarRange aspartofalargerunitofthe
(Donnellan et al. 1999; Mahony et al. 2000). eastern escarpment of the New England Tableland,
A detailed account of the frogs of the New which extends from the Macleay River incursion
England Tablelands region, an area about nine in the south to the Clarence River incursion in the
times larger in extent than the Gibraltar Range, was north. Two species associated with the fast-flowing
presented by Heatwole et al. (1995). The Gibraltar streams of the upper escarpment, L. piperata
Range is adjacent to the north-east of this region and L. subglandulosa, are found only within this
and the western portion ofthe range was included in region. Litoria daviesae, a sibling species of L.
their investigation. They reported 46 species in the subglandulosa, occurs to the south of the Macleay
New England region and concluded that the largest River catchment, and L. pearsoniana, a sibling ofL.
numbers were associated with moist habitats that are piperata, occurs in the mesic forests on the northern
disfributed along the east coast and onto the Great side of the Clarence catchment. Among the ground
M
Dividing Range. They did not have extensive data frogs, balbus reaches the extent ofits disfribution
from the Gibraltar Range region and inspection of at the northern incursion ofthe Clarence River, and
their data reveals that most of their records were to the north a sibling species, M. fleayi, occurs in
A
from along the Gwydir Highway, which cuts east- mesic forest habitats. similar pattern occurs within
west across the range, and a small number ofsites in Philoria, to the north ofthe incursion ofthe Clarence
the Gibraltar Range National Park. Nonetheless, the RiverP. pughi is replaced byP. kundagungan, and to
current study provides sfrong support for their major the northeast by P. loveridgei and P. richmondensis
conclusion. The 30 species present in the Gibraltar (Rnowlesetal. 2004). This genusmorethananyother
Range account for 65% of the total number they is indicative ofthe isolationofmesic foresthabitats in
reported for the larger region. It is evident that the north-easternNew South Wales inthepast 15 million
mesic habitats of the Great Escarpment and coastal years (Knowles et al. 2004).
beltprovide adiversityofhabitats andthis isreflected
Proc. Linn. Soc. N.S.W., 127, 2006 89
.
AMPHIBIANS OF THE GIBRALTAR RANGE
Despite the protection of large portions of detected during intensive searches conducted in the
the Gibraltar Range in conservation reserves a 1990s at any of the locations named in the species'
considerable number of the frogs found there are description (NSW NPWS 1994; SF NSW 1995).
classified as threatened. Nine of the 30 species are Searches were extended to likely habitats within the
categorized as either endangered or vulnerable. In region and small "peppered" tree fi-ogs were foimd at
the case ofthose species found in isolated rainforest Rockadooie and Seven Mile Creeks in the catchment
remnants the categorization is related to small of the Rocky (Timbarra) River in the north-west
population size and limited distribution, and the region of the Gibraltar Range, and at Cooraldooral
potential factors threatening their short-term survival Creek, a catchment ofthe Mann River, in the south-
are associatedwithhabitat loss, changes inhydrology west region in Gibraltar Range. Other populations
and pollution. In the long-term their evolutionary were detected on the Timbarra Plateau (Nelsons
potential may be impacted by climate change. A Creek) to the north ofthe Gibraltar Range.
similarexplanationisnotpossibleforthosethreatened Genetic comparisons of the "peppered" frogs
species that are found invegetation communities that fi-om each of these sites with a larger collection
are more widespread or those not limited to specific of specimens of members of the Litoria citropa
vegetation communities. species group fi-om across the Great Escarpment
Most threatened are frogs that breed in streams and coastal belt placed these specimens within the
and are associated with stream habitats, they include species recognized as the Barrington Tree Frog
M
L. piperata, L. subglandulosa, M. balbus and {Litoria barringtonesis; Donnellan et al. 1999). Such
iteratus. There is extensive habitat for these species a result would normally lead to a questioning ofthe
in the Gibraltar Range and in the wider region. It is taxonomic status of the Peppered Frog. However,
difficult to argue that declines in abundance and the because no specimens couldbe collected from any of
disappearance oftheir populations are due primarily the historical sites listed in the species' description,
to habitat loss or degradation. Undoubtedly, habitat and suitable genetic material could not be extracted
modification, particularly on the tablelands where fi-om the fixed museum specimens to be included in
there is a long history of agricultural activity may appropriategeneticcomparisons,thequestionremains
have impactedon species such asL. booroolongensis, open. Furthermore, the type series of L. piperata,
but this explanation is not tenable across the wider whichconsistsofover70 specimens, hasbeenclosely
distributions of these species. It is most likely that examined, and there is general agreement among
the cause of declines is due to the impact of an herpetologists that L. piperata is distinctly different
invasive pathogenic fungus that causes the disease fromL. barringtonensis
chytridiomycosis in fi-ogs (Berger et al. 1998, 2004). The Peppered Frog is listed as endangered and a
WNPWS
High altitude stream fi-ogs are known to be most RecoveryPlanhasbeenprepared(NS 2001).
susceptibleto this disease (Bergeret al. 2004) andthe If we accept the position that it is morphologically
threat to their long-term persistence remains in the distinct, then there is no evidence of an extant
balance. population and the species should be considered
One species of conservation significance, the as presumed extinct. Whatever the situation, the
peppered fi-og (Z,. piperata), deserves more detailed Gibraltar Range provides important high altitude
consideration. This fi"og was described in 1985 from plateau and escarpment streams considered to be the
a small number ofhigh altitude locations distributed habitat ofthis frog.
on the edge of the Great Escarpment in the New
England region, extending from the Oxley River
ACKNOWLEDGEMENTS
Gorge (GaraRiver) inthe southto several sites onthe
headwaters ofthe Clarence River inthe north (Mann,
Oban, Henry and Sara Rivers; Tyler and Davies Iammostgratefulfortheassistanceofnumerouscolleagues
1985). All specimens, with the exception of two during fieldwork, in particular Steve Donnellan, Ross
collected at the Gara River in 1952, were collected Knowles, Andrew Stauber, Karen Thumm and Stephen
Mahony. Long-term monitoring of stream frogs was
in the early 1970s. Several specimens were obtained
supportedbyagrantfromEarthwatchandmanyvolunteers
fi-om Diehard Creek, which drains south-west from
assistedwiththefieldwork.
the Gibraltar Range to the Mann River. Conservation
assessments ofthe peppered fi-og have been fi-aught
withdifficulty.Nospecimensofthisorothermembers
of its species group {Litoria citropa species group,
Tyler and Davies 1978; Donnellan et al. 1999) were
90 Proc. Linn. Soc. N.S.W., 127, 2006
MAHONY
M.
REFERENCES
pearsoniana) from mid-eastAustralia. Molecular
Ecology 7,175-1^6.
Anstis, M. (2002). 'Tadpoles ofsouth-easternAustralia: a New SouthWalesNational Parks andWildlife Service.
guide withkeys'. (ReedNew Holland, Sydney). (1994). Fauna ofnorth-eastNSW forests. North East
Berger, L., Speare, R., Daszak, P., Green, D.E., Forests BiodiversityReportNo. 3. New SouthWales
Cunningham,A.A., Goggin, C. L., Slocombe, R., National Parks andWildlife Service.
Ragan, M.A., Hyatt,A.D., McDonald, K. R., Hines, New SouthWalesNational Parks andWildlife Service.
H. B., Lips, K.R., Marrantelli G. andParkes, H. (2001). Yellow-spottedBell Frog (Litoriacastanea)
(1998). Chytridiomycosis causes amphibianmortality and PepperedTree Frog (Litoriapiperata) Recovery
associatedwithpopulation declines inthe rainforest Plan. (NPWS Hurstville, NSW).
ofAustraliaand CentralAmerica. Proceedings ofthe Nix, H.A. (1991). Biogeography: patterns andprocesses.
NationalAcademyofScience USA 95, 9031-9036. In: 'RainforestAnimals.Atlas ofVertebrates Endemic
Berger, L., Speare, R., Hines, H.B., Marantelli, G., Hyatt, toAustralia'sWetTropics (Kowari 1)' (Eds H.A. Nix
A.D., McDonald, K.R., Sherratt, L.F., Olsen, V, andM.A. Switzer) pp.10-39. (AustralianNational
Clarke, J.M., Gillespie, G., Mahony, M.J., Sheppard, Parks andWildlife Service, Canberra).
N., Williams, C. andTyler, M.J. (2004). Effectof Oilier, CD. (1982). The Great Escarpment ofeastern
seasonandtemperature onmortalityinamphibians Australia: tectonic andgeomorphic significance.
dueto chytridiomycosis.Australian Veterinary Journalofthe GeologicalSocietyofAustralian 29,
Journal82(7), 434-439. 13-23.
Cogger, H.G. (2000). 'Reptiles andAmphibians of Price, L. (2004) HonoursThesis, UniversityofNewcastle,
NSW
Australia'. (6* ed. Reed, Sydney). Australia.
Daugherty C.H. andMaxsonL.R. (1982).Abiochemical Quilty, P.A. (1994). Thebackground: 144millionyears of
assessmentofthe evolution ofMyobatrachine frogs. Australianpalaeoclimatic andpalaeogeography. In
Herpetological3Si3), 341-348. 'HistoryofTheAustralianVegetation: Cretaceous
Donnellan, S.C, Mahony, M.J. andDavies, M. (1990).A to Recent' (Ed. R.S. Hill)pp. 14-43. (Cambridge
new species ofMixophyes (Anura: Leptodactylidae) University Press, Cambridge).
andfirstrecordofthe genus inNew Guinea. Roberts, J.D. andWatsonG.F. (1993). Biogeographyand
Herpetologica46(3), 266-274. phylogenyoftheAnura. In 'The FaunaofAustralia
Doimellan, S.C, McGuigan, K., Knowles, R., Mahony, Vol. 2aAmphibiaandReptilia'. (Eds C.J. Glasby,
M.J. andMoritz, C. (1999). Genetic evidence for G.J.B Ross andPL. Beesley)pp. 35-40. (Australian
speciesboundaries in fi-ogs oftheLitoriacitropa GovernmentPrinting Service, Canberra).
species group (Anura: Hylidae). AustralianJournal Robinson, M. (1993). 'Afieldguideto Frogs ofAustralia.
ofZoology47, 275-293. FromPortAugustato EraserIslandincluding
Heatwole, H., de Bavay, J., Webber, R andWebb, G. Tasmania'. (Reed, Sydney).
(1995). Faunal surveyofNew England. IV. The Smith,A.R,Andrews, S.P andMoore, D.M. (1994).
Frogs. Memoirs ofthe QueenslandMuseum 38(1), Terrestrial fauna ofthe Grafton andCasino State
229-249. ForestManagementAreas. Descriptionand
Heyer, W.R. andLeim, D.S. (1996).Analysis of AssessmentofForestry Impacts. Grafton-Casino
intergenericrelationships oftheAustralian frog ManagementAreaEIS SupportingdocumentNumber
familyMyobatrachidae. Smithsonian Contributions 1. State ForestofNew SouthWales,Northern
toZoo/ogyNo. 233, 1-29. Regions, Coffs Harbour.
Knowles, R., Mahony, M.J.,Armstrong, J. andDoimellan, StateForestofNew SouthWales. (1995). Proposed
S. (2004). Systematics ofsphagnum fi-ogs ofthe forestryOperations inthe TenterfieldManagement
genusPhiloria (Anura: Myobatrachidae) in eastern Area. Vol. D. Environmental Impact Statement.
Australia.Records oftheAustralian Museum 56, 57- FaunaImpact Statement.
74. TylerM.J. (1979). Herpetofaunalrelationships ofSouth
Mahony, M. J. andKnowles, R. (1994). 'Ataxonomic AmericawithAustralia. In 'The SouthAmerican
review ofselectedfrogs ofnorth-eastNSW forests'. herpetofauna: Its origin, evolution, anddispersal'.
InNorthEastForests Biodiversity ReportNo. 3g. (Ed. W.E. Duellman) pp. 73-106. Universityof
New SouthWalesNationalParks andWildlife KansasMuseumNaturalHistoryMonogrograh 7,1-
485.
Service.
Mahony, M.J., Knowles, R., Foster, R. andDoimellan. S. Tyler, M.J. andDavies, M. (1978). Species groupswithin
(2000). Systematics oftheLitoriacitropa (Anura: theAustralo-PapuanHylidgenusLitoriaTschudi.
Hylidae) complex innorthernNew SouthWales AustralianJournalofZoology, Supplementary Series
and southernQueensland. Records oftheAustralian 63,1-47.
Museum. 53, 37-48. Tyler, M.J. andDavies, M. (1985).Anew species of
McGuigan, K., McDonald, K.M., Parris, K. andMoritz, C. Litoria(Anura: Hylidae) fromNew SouthWales,
DNA
(1998). Mitochondrial diversity andhistorical Australia. Copeia 1985(1),1145-1149.
biogeography ofawet forest-restricted fi-og {Litoria
Proc. Linn. Soc. N.S.W., 127, 2006 91