REMNANT AT INVERLEIGH, VICTORIA
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Corella, 2002, 26(2): 41-46
LOCAL EXTINCTION AND DECLINE OF BIRDS IN A WOODLAND
REMNANT AT INVERLEIGH, VICTORIA
L. E. CONOLE
2/37 Myrnong Crescent, Ascol Yale, Victoria 3032
E-mail
Retci,wl. ::!8 April 2000
Between 1979-2000 data about the presence or absence of birds were opportunistically collected from a
grassy woodland reserve on the edge of the Victorian Volcanic Plain (38 ° 04'S, 144°03'E). Victoria. Whilst no
estimates of absolute abundance were made, the observations over 20 years are representative of avifaunal
change during that period. In the last three decades of the twentieth century, 22 bird species have either declined
or become locally extinct in the reserve - 23 per cent of locally breeding species. These changes are important
because they involve some species not known to be in decline elsewhere, and because they are occurring in a
relatively large woodland remnant (1 050 ha). The opportunities for small, woodland-specialist birds to recolonize
from nearby areas are extremely limited, as most nearby remnants are not connected and are generally smaller,
species-poor and experiencing species loss. Many of the local extinctions are probably not naturally reversible
in the current landscape.
INTRODUCTION THE STUDY AREA
Between 1979-2000. I undertook investigations into IFFR is on the eastern edge of the Victorian Volcanic Plain (38 °0.:l'S.
l44°03'E). about 30 kilometres west of the large provincial city of
various aspects of the conservation biology and ecology of Gcclong. The reserve comprises I 050 hectares of grassy woodland.
arboreal and volanl mammals (possums, gliders and bats) predominantly of River Red Gum E11ralyp11u calllald11/e11si., and a
within the lnverleigh Flora and Fauna Reserve I IFFR] rough-barked form of Manna Gum £. vi111i11alis. IFFR has a long
(Conole and Baverstock 1985; in prep.). During that period, history of exploitation for local domestic firewood, and during the
I opportunistically collected information relating to other I960s, about IO per cent of the reserve was cleared of Manna Gum
by the Forcsls Commission of Y icloria and rcplanled with non
fauna and flora, particularly the birds. The data are
indigenous £11rnlyp111s species (moslly Sugar Gum £. claducalyx and
presence or absence in nature, and whi 1st no estimates of lronbark £. sideruxy/011/tricarpa) (Sheehan 1992). The original town
absolute abundance have been made, the observations from common and state forest allotments were combined to make Ihe
41 visits over 20 years give an accurate picture of avifaunal reserve in 1988 (Sheehan I 992).
change during that period. IFFR is relatively isolaled, and is only very loosely connected by
discontinuous, narrow strips of degraded native vcgclation to Ihe Leigh
Between 1951 and 1973, Wheeler (circa 1973) recorded
River. Barwon River and Native Hut Creek (within 1-5 km), and along
96 species of forest and woodland birds at IFFR. Between similar poor quality roadsides to the 13annockburn Recreation Reserve
1978 and 1989 I recorded 96 species of forest and (rirrn 300 ha) 6 kilometres to the SE. OIher small and degraded
woodland birds, but between 1990 and 2000 I recorded remnants exist around Teesdale, just east of IFFR. Substantial areas
only 86 species of forest and woodland birds at IFFR. of forest and woodland (>IO 000 ha) in the 13risbane Ranges National
Park. Enfield State Forest and Otway Ranges are separaIed from IFFR
Since the baseline drawn in the early 1970s (Wheeler circa by between 20-40 kilomelres of cleared agricultural land (see Fig. I).
I 973). I have documented the local extinction of I 3 bird The land clearing that led to this fragmcntalion and degradation took
species al lnverleigh, representing approximately l 0-15 per place between 50 and I 00 years ago.
cent or sedentary, breeding species. Another nine species
(9%) have become rarer, and may become locally extinct METHODS
in the near future. In total, 22 species (23%) of locally
Though birds were of secondary interest in some of the 41 trips to
breeding species have declined - some to the point of IFFR, a consistent approach to surveying was taken. I cilhcr walked
local extinction. Although this pulse of species loss can be over large parts of the reserve on each trip, or drove between multiple
seen as part of a widespread extinction wave in woodland locations and walked around at each. A record was kepi of all bird
birds in south-eastern Australia (Robinson 1994; Robinson species seen or heard. Records were entered into a Uirdlnfo database
and Trai 11 1996; Reid 1999), some of the species are not (lntelligenl 13irding, Canberra, Australia) and analysed for species
occurrence by year from 1979-2000.
generally thought of as part of this wider trend. By the
early years of the 21st century, it seems likely that the Taxonomy follows Christidis and 13oles ( 1994) for species. Schoddc
sedentary, breeding component of the JFFR avifauna will and Mason (1997) for non-passerinc and Schoddc and Mason (1999)
have been reduced by up to 20 per cent in a period of for passerine sub-species (or 'ultrataxa'). The subspecies is noted if more
than one subspecies occurs in Victoria. This approach was used to
about three decades after apparently being relatively stable ensure that the most accurate taxonomic units were used when
throughout most of the 20th century. discussing local extinctions.
4142 L. E. Conole: Birds at lnverleigh, Victoria Corella 26(2)
In grouping the species which have either exhibited
marked decline or become locally extinct since about 1970,
some patterns are evident (see Tables 2 and 3):
• All the selected species are primarily insectivorous.
• The largest grouping is one of species that forage
predominantly on the ground or in structures very close
to the ground (Scarlet Robin, Hooded Robin, White
browed Scrubwren, Speckled Warbler, Brown Thornbill,
Buff-rumped Thornbill, Brown Treecreeper, Eastern
Spinebill, White-winged Chough, Grey l3utcherbird).
• Another grouping requires dead, standing or fallen wood
as a foraging substrate or perch from which to forage
(Scarlet Robin, Hooded Robin, Brown Treecrcepcr,
White-throated Treecrccper, Varied Sittella).
• All are breeding, sedentary species susceptible to exotic
predators in a landscape island (e.g. Black Rat Rattu.1·
rattus, Fox Vulpes 1111/pes, Cat Fe/is carus), or to major
changes in habitat structure and floristics.
There does not appear to be any universality with
respect to positioning or type of nest. Some of the
species in decline nest on or near the ground, which
figure I. Mop of main veg43
L. E. Conole: Birds at lnverleigh, Victoria
June, 2002
TABLE l
Birds of changed slatus in 1hc lnvcrlcigh Flora and Fauna Reserve. Defini1ions modified from Pescoll ( 1 983):
= = =
E locally ex1inc1: R rare (few recorded and would only be found by system:11,c searchmg): U uncommon
(unusual. can be seen if Lime is spenl searching. bul not common): C = common (can usu� lly be seen by lhc
average observer): V = vagranl (beyond 1hcir normal range): L = localized (only found m localized hab1tal
palchcs in reserve).
Assessment of s1a1Us
Species Pcscoll ( 1 983) Conole 2000
Emu Dmmai11.1· 11ovael,o//a11diae E
Australian Buslard Ardeo1is a11.,·1rali.v E E
Bush Slone-curlew 811rhi1111s grallari11s R E
Purple-crowned Lorikeet Glosl·opsilla porphymcephala u C
Swifl Parrot La1ha11111.1· discolor R V
Barking Owl Ni11ox co1111ive11s E
Masked Owl Tyw 11ol'aehol/a11diae 11ovaeholla1u/iae R
While-backccl Swallow Cheramoeca le11costem11s V
Sacred Kingfisher Todirhamplws .rn11c/1,s C u
Fan-iailed Cuckoo Caco111a111i.1· flabelliformi.1· C u
Horsfield's Bronze-Cuckoo Chrysocoffyx basali.,· C u
Shining Bronze-Cuckoo Chry.rnrorcyx Jurid11s plago.rns C u
13assian Thrush Zoothera lw111la1a lw111/ata R V
Scarlcl Robin l'etroil"ll 11111lticolor booda11g C E
Hooded Robin Mela,wdryas rnrnl/ara rncullaw R E
Jacky Winier Mirroeca fasci11a11s fasri11a11s u R
Salin Flyca1chcr Myiagra cya11ole11ca u V
Rufous Songlark Ci11dorhamph11s ma//hewsi u R
Whilc-browcd Scrubwren Sericomis fro111alis fro111a/is C E
Speckled Warbler Pyrrlwlae11111s .rngiua111s R E
Weebill Smicromis bre1•irostris brevirostris u V
Yellow TI1ornbill Aca111hiza 11a11a modes/a u R
Brown Thornbill Aca111hi:a p11silla pusilla C E
Buff-rumped Thombill Aca111hi:a reg11/oides reg11loide.1· C E
Sou1hcrn Whi1efacc Aphe/ocephala leucopsi.r leucopsi., R V
Whi1c-1hroatc44 E. Conole: Birds at lnverleigh, Victoria
L. Corella 26(2)
TABLE 3
Breeding resident species of changed status tabulated with nesting subsu·ate and height (based on Bcruldson 1980).
Nest
Species Substrate Height Status change
Scarlet Robin 13ark/fork/spout 1-20 111 Locally extinct
Hooded Robin Spout/stump/forkL. E. Conole: Birds at lnverleigh, Victoria 45
June, 2002
Overall, it could be said that a more floristically and Although it is expected that island populations will have
structurally diverse shrub layer should be encouraged for a higher than average chance of becoming extinct, at l 050
avian conservation. That the middle and ground storey hectares IFFR is not a typical small remnant woodland
were once more diverse and complex is evidenced by (Ford 1989). It seems l ikely that another 5-10 species
_
remnant specimens of Dogwood Cassinia aculeata (e.g. Jacky Winter, Diamond Firetail, Varied Sittella, White
( I plant) and C. arcuata (46 L. E. Conole: Birds at lnverl eigh, Victoria Corella 26(2)
and Teesdale Recreation Reserves, and corridors along Hughes. D. ( 1994). Poaching at lnvcrleigh Common. Vic. Bird Obs.
roadsides and watercourses. Once habitat values have been 742: 1 1 .
kssop, R., Wilson, l:l . and Lindros. J . ( 1988). 'Flora and Fauna Database
restored. consideration might also be given to the - Gcelong Region.' (Geelong Environment Council: Gcelong.)
reintroduction of selected species. Mac Nally, R., Parkinson. A., Horrocks. G.. Conole. L. and Tzaros, C.
(200 I). Relationships Between Terrestrial Vertebrate Diversity.
ACKNOWLEDGMENTS Abundance and Availability of Coarse Woody Debris on Sou1h-eas1ern
Australian Floodplains. Biol. Co11s. 99: I91- 205.
I am indebted to the following people who have variously MarchanI. S. ( 1979). The birds of fores! and woodland near Moruya.
accompanied me in the field, encouraged or supported my interest in N.S.W. Aust. Birds 13: 87-88.
woodland birds. or engaged in interesting and helpful conversations on Pescoll, T. ( I983). · Birds of Gcclong.' (Neptune: Gcclong.)
the subject: the late Jack Wheeler. Gordon McCarthy, Gran! Baverstock. Recher. H. F. ( I99 I). The conservation and management of eucalypt
Ray Bavcrstock. Andrew Bennett. Trevor Pcscott. Ralph Mac Nally. forest birds: resource requirements for nesting and foraging. In
Simon Kennedy. Barry Traill and Mark Trengove. Thank you also 10 'Conservation of Australia's Forest Fauna. (Ed D. Lunney.) (Royal
an anonymous referee and A. Cam for editorial assistance. Zoological Society of NSW: Sydney.)
Recher. H. F. and Holmes, R. T. ( 1985). Foraging ecology and seasonal
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