James Cook University: Completed
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The inland forest bat, Vespadelus baverstocki,
one of the smallest mammal species in Australia, if not the world.
Weighing between 3-5 grams, and found in the south-western parts of
the Desert Uplands. They can consume 1-1.5 times their body weight
in insects per night—and therefore play an essential
regulatory role in the ecosystem. An animal to be celebrated not
persecuted.
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The Crucifix or Holy-cross toad. A sandy soil
dweller that can live for years deep underground enveloped in a
cocoon of its own making, waiting for very heavy rains to signal
time to breed. Adults are much larger and less brightly coloured,
and they all extrude a thick toxic latex when handled, essential
predator avoidance strategy when shining like a glowing McDonalds'
sign.
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Oedura castelnaui, the northern velvet gecko.
One of the variety of three allied velvet geckos in the Desert
Uplands. It hides under heavy bark of tree such as gidgee and black
gidgee during the day, coming out at night to feed on a variety of
insects and spiders.
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It's not easy being endangered: a Julia Creek
Dunnart, Sminthopsis douglasi, expresses its absolute fury at being
fiddled with by a well-meaning zoologist. Restricted to the
cracking grey clays typical of the Mitchell Grass Downs, its
discovery in outlying Astrebla grasslands in the Desert Uplands was
a bonus and extended its known range.
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Alex Kutt
Commenced 1996
Background | Fauna Survey |
Unexpected finds and new species | Feral cat diet | Application of
the research | Future directions |
The Desert Uplands (DEU) is one of Queensland's six tropical
savanna bioregions, covering more than 6 million hectares and
sharing boundaries with the Mitchell Grass Downs to the west, the
Brigalow Belt to the south and east, and the Einasleigh Uplands to
the north. The DEU has a semi-arid climate with vegetation
consisting of predominantly acacia and eucalypt woodlands,
ephemeral lake habitats and grasslands. It straddles the Great
Divide between Charters Towers, Hughenden and Blackall and it is
this situation between the wet east coast and the dry interior
which makes this area of biological and biogeographic interest.
Unlike the coastal zone and Cape York Peninsula, the vertebrate
fauna of Queensland's tropical savannas are almost entirely unknown
and unsurveyed, quite inexplicable given the mounting need to find
an effective balance between the twin land-management goals of
economic viability and nature conservation. The project contributes
to the TS-CRC research project Vertebrate Biogeography and to the
Desert Uplands Management Study.
The survey was undertaken in the Desert Uplands between 1997 and
2000, and was predominantly designed to identify fauna assemblages
of the regional ecosystems (the lowest level bioregional planning
unit sensu Sattler and Williams 1999), to describe the patterns of
the variation in distribution, diversity and abundance of these
assemblages, and to characterise the region's biogeographic
position within the Queensland landscape.
Sampling in the survey used a standardised nested quadrat array
as the basic trapping unit, modified from the strategy developed by
Dr John Woinarski for bioregional surveys undertaken by Parks &
Wildlife Commission of the NT. This approach uses a set combination
of Elliott, cage and pitfall traps with timed day and night
searches and bird counts. Incidental fauna records were also
collected and a thorough search of all other reliable secondary
data sources was made and incorporated into the final database.
Three years later after 23,000 Elliott and cage trap nights,
4200 pitfall trap nights, 600 individual 20 litre buckets dug, more
than 7km of drift fence installed and the equivalent of almost
seven weeks at 24 hours-a-day of active searching, the field survey
was completed. The simple but primary outcome was a database of
more than 35,000 records (24,000 from field survey), representing
433 species and translating to 11,300 unique species
localities.
As one would hope for a predominantly unsurveyed bioregion,
there were a number of unexpected finds and range extensions
including Spinifexbird and Painted finches, rodents and dasyurids
such as the Lakeland Downs mouse Leggadina lakedownensis ,
Desert Mouse Pseudomys desertor and Pebble-mound mouse Pseudomys
patius , Common Dunnart Sminthopsis macroura and the
Julia Creek Dunnart Sminthopsis douglasi , and reptiles like
the Brigalow Scaly-foot Paradelma orientalis and the Centralian
Blue-tongue lizard Tiliqua multifasciata.
And the highlight (satisfying a zoologist's unspoken of desire
for immortality) with the discovery of two new species, both
reptiles: Ctenotus terrarossa sp. nov, (the etymology identifying
the deep red sandy habitat in which it was found and is seemingly
restricted to), currently being described in conjunction with the
Queensland Museum; and Lerista sp. nov., still awaiting a formal
classification.
As an adjunct to the trapping survey, the diet of feral cats
were examined via their stomach contents. The cats were collected
systematically across the bioregion and the directly adjacent areas
of the Mitchell Grass Downs and Northern Brigalow Belt.
Samples were obtained by local professional kangaroo and pig
shooters, and those participating were furnished with a collection
kit containing preservatives and sample containers, labels for
recording locality and morphometric data for the cat. A small
bounty was paid to the shooters to facilitate and maintain their
interest in the project.
Gut content samples obtained were then washed, sorted and
identified to the lowest taxonomic level possible. The Queensland
Museum verified gut material that could not be identified
confidently and intact, good-quality specimens were incorporated
into their collections. A total of 194 cat guts were collected over
a two-year period, comprising 1300 prey items. While this number is
large, it is likely that it is far less prey than these cats
actually consume.
Of all prey items identified, 16 per cent were birds, 33 per
cent reptiles, 5 per cent amphibians, 25 per cent mammals, and 21
per cent insects. Conversely the proportion of taxonomic groups
represented on a per cat basis equates to 33 per cent containing
bird prey items, 63 per cent reptiles, 9 per cent, amphibians, 47
per cent mammals and 42 per cent insects.
Because feral cats are not an economic pest, they are generally
ignored as a target for research - except where re-introduction or
management of rare species is in conflict. The lack of systematic
Australia-wide examination of regional and local patterns and
impacts is worrying, as the influence of feral cats on native
fauna, particularly in recently modified habitats, is not well
understood. These data will hopefully contribute to the debate
regarding the effects of cat predation.
While there is obvious value in information where none
previously existed, this survey will also provide a spectrum of
outputs including:
- examination of the recent and later biogeographic patterns of
the Desert Uplands fauna and distribution (it seems the bioregion
is both barrier and refuge for the Torresian fauna of the coast and
the Eyrean fauna of the inland);
- the environmental determinants controlling the local and
regional patterns of fauna assemblages, including the influence of
spatial scale (vertebrate fauna can be characterised into discrete
assemblages based on abundance at local sites, species interactions
and environmental characteristics, though on larger scales the
species composition and structure changes according to area of
habitat and geographic location in the regional landscape);
- how adequately landscape units act as a surrogate for
identifying vertebrate fauna assemblages (apart from the species'
abundance and distribution, vertebrate fauna assemblages can be
characterised on multiple overlapping levels, be it vegetation,
habitat or landscape or management units. However the adequacy of
these partitions vary enormously in their ability to act as a
surrogate for capturing and describing the fauna diversity across
the bioregion);
- on a smaller scale the influence of fire and grazing on fauna
within a particular vegetation association (in spinifex-dominated
woodlands, fire is an important influence on fauna assemblage, due
to changes in vegetation composition and structure, though grazing
complicates pattern of structural change to the disadvantage of
some species); and finally
- using the current system of protected areas created using
regional ecosystems as the planning unit, test how well the fauna
diversity is represented, what additional or alternative reserve
designs would be needed to adequately capture the majority of
species, and what species or groups act most suitable surrogate for
the entire species pool.
This inventory is merely a snapshot of the vertebrate fauna in
the bioregion and barely provides a baseline from which to extend
our understanding of the dynamics of wildlife in a rapidly
modifying landscape. One key future goal is passing the information
back to the Desert Uplands community, via an atlas of distribution
or a field guide to describe the variety and ecology of the species
in the area. The data will also be used in Draft Desert Uplands
Conservation Strategy (EPA)
Additional targeted follow up work is also essential, such as
directly examining in detail the interplay between to the variety
of land management regimes (fire frequency, stocking rates, tree
clearing) and how best to balance needs for farm viability with
native fauna protection.
