Teacher guide to Namoi ‘special place’
Background document
Site 5: Yarrie Lake Flora and Fauna Reserve, Narrabri/Wee Waa
5.1
Introduction
Welcome to the Special place pack for Yarrie Lake, which is between Narrabri and Wee Waa.
Yarrie Lake is an important part of a network of remnants of native vegetation. When visiting,
you will study an endangered ecological community within the native vegetation remnant
around the lake. Remnant vegetation adds value to the region, by providing important services
to the agriculture industry and local communities (e.g. the forest provides habitat for bats,
which help farmers by reducing numbers of insect pests). The surveys undertaken during the
visit can be used to evaluate the environmental services this remnant provides to those who
live around it.
Students can undertake field tasks from the activities in the education package. The tasks can
be completed as individual or combined components over one or multiple day trips,
depending on student numbers, time constraints and teacher support.
While at the site you will see physical signs of pre-European Aboriginal occupation. In the
woodland, 400-year-old trees that are still standing tell some of the story of the Kamilaroi
(also known as Gomilaroi and other spellings) people in the area. Visitors can also learn
firsthand the vastly different ways the two cultures – the Kamilaroi and the current residents –
manage the landscape. One difference is that the Kamilaroi were able to make use of trees
without destroying them. For example, bark was removed to make canoes, coolamons
(shallow vessels) and even shields, leaving a scar on the tree. The scarred tree continued to
live and thus to provide other environmental services (e.g. shade, firewood and even oxygen
to breathe). In modern European land use, vegetation is removed or severely altered to
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provide a landscape suitable for agricultural purposes; these changes mean that other
environmental services are lost from the landscape.
Special features of Yarrie Lake Flora and Fauna Reserve
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Close proximity to the centres of Narrabri (26 km) and Wee Waa (25 km)
Quiet – away from busy roads
Free access
Wheelchair access may be possible for parts of Yarrie Lake; however, it is best to visit the
area before the trip because the unsealed road and track may have access limitations
Amenities (toilets, picnic shelters and drinking water)
Area of approximately 400 hectares that:
o contains high-quality remnants of the Brigalow open forest endangered ecological
community (EEC) and bimble box woodland
o has a high diversity of plants (native grasses, herbs, shrubs and trees) and animals
(birds, mammals and reptiles)
Yarrie Lake is a recreational area used by water skiers, fishers, bushwalkers and so on. The
lake is often dry, but during wetter periods it contains shallow water that is ‘milky’, due to
suspended clay particles washed in from creeks and the Pilliga Scrub. Some believe that the
depression was caused by a meteor impact many thousands of years ago, but without
scientific evidence, this story will remain a colourful local myth.
Historically, Yarrie Lake was only filled through natural drainage. However in-flowing creeks
have been excavated to facilitate drainage after rainfall events (ABC 2009). These
modifications have increased the amount of water in the lake and the length of time it holds
water.
Yarrie Lake Flora and Fauna Reserve is also special because, as can be seen on Google Earth,
it is an island refuge in a highly fragmented landscape. This is due to large-scale clearing,
primarily for agriculture and, increasingly, for the mining industries.
When natural areas become isolated, species are at risk of local extinction. For example, after
a catastrophic event (e.g. bush fire) some species may die out. However, if another
community that is not affected by the fire occurs close by, there is capacity for recolonisation.
The greater the distance between natural areas, the fewer plant and animal species can
recolonise. Some of these species may be key to maintaining a healthy food web, and
providing valuable environmental services. Pilliga Scrub is located to the south and Mount
Kaputar to the east. Throughout the region, there are a with a few small remnant reserves
dotted around that provide ‘stepping stones’ between the larger areas of native habitat. These
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reserves include Claremont Nature Reserve, Brigalow Park Nature Reserve, Pilliga State
Forest, Culgoora State Forest and Mount Kaputar National Park. In the region around Yarrie
Lake, 13 threatened plants (flora) and seven threatened animals (fauna) have been recorded.
5.2
Flora of Yarrie Lake Flora and Fauna Reserve
Figure 5.1
River red gum (Eucalyptus camaldulensis) around the edge of Yarrie Lake
Yarrie Lake Flora and Fauna Reserve contains bimble box woodland (Fig. 5.2) and the
brigalow EEC (Figs 5.3, 5.4) (OEH n.d., DSEWPAC 2012) that was once common across
northwestern New South Wales (NSW). The NSW Threatened Species Conservation Act
1995 (TSC Act) defines an ecological community as ‘an assemblage of species occupying a
particular area’. Areas of dense regrowth of white cypress pine seen at the Yarrie Lake (Fig.
5.8) provide little habitat value. The brigalow remnant (on the western side of the lake) is
dominated by immature trees, as a result of clearing practices in the early 1900s. Many areas
of brigalow are now dominated by homogeneous stands of immature trees of dense regrowth.
Plants that typically occur within the brigalow community include belah (Fig. 5.5), wilga (Fig.
5.5) and pilliga box (Eucalyptus pilligensis). The healthy area of bimble box woodland
(eastern side) contains trees of different ages and has many trees that have hollows (Fig. 5.6).
Hollows provide important habitat for birds and small mammals such as bats (Fig. 5.7).
Also around Yarrie Lake are areas of dense regrowth of white cypress pine (Fig. 5.8) that
provide little habitat value for flora and fauna
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Figure 5.2
Bimble box (Eucalyptus populnea subsp. bimbil) woodland
Figure 5.3
Brigalow EEC at Yarrie Lake Flora and Fauna Reserve
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Figure 5.4
Brigalow (Acacia harpophylla) found within a remnant brigalow community
Mature trees are typically tall with foliage at
the top (as in the central tree). Brigalow tree
regrowth from suckers is dense, as can be seen
in the surrounding denser growth in the
background.
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Figure 5.5
Other brigalow community plants include belah (Casuarina cristata) (canopy)
and wilga (Geijera parviflora) (shrub layer)
Figure 5.6
A typical hollow of a mature tree that provides habitat for native animals
Hollows of different sizes accommodate different species of animals. Without the hollows of mature
trees, many native animals, including threatened animals, would not have a home or protection.
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Figure 5.7
Bats roosting in a tree hollow by day will forage at night
Figure 5.8
Areas of white cypress pine (Callitris glaucophylla) regrowth (e.g. along Yarrie
Lake Road) exclude understorey plants as the stand increases in density
Many weeds are found in the reserve, including mother of millions, prickly pear, buffel grass,
African lovegrass, red natal grass, green panic (Fig. 5.9), cobbler’s pegs and johnsons grass.
These weeds pose a serious threat to Yarrie Lake Flora and Fauna Reserve.
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Figure 5.9. Bimble Box woodland with the weedy grass, green panic, invading the understorey
Evidence of traditional Aboriginal culture can be seen at Yarrie Lake by the presence at the
survey site of scar trees (Fig. 5.10) and nardoo (Fig. 5.11). Nardoo is a fern that was used as a
food by traditional Aboriginal people; the plant produces shoots whenever the area receives
significant rains. It produces its spores on damp mud as the floodwaters recede. Aboriginal
people would roast the spore cases (sporocarps), to make them non-toxic, before grinding
them. This simple step of adding heat completely breaks down thiaminase, a toxin that robs
the body of vitamin B1. It is believed that Burke and Wills, running out of food near Coopers
Creek, turned to nardoo as their salvation, and that this may have actually killed them.
Unfortunately, Burke and Wills did not roast the sporocarps before grinding them (Nash
2004).
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Figure 5.10
Scar tree at Yarrie Lake
Figure 5.11
Nardoo (Marsilea drummondii) at Yarrie Lake
5.3
Fauna of Yarrie Lake Flora and Fauna Reserve
Yarrie Lake and surrounding vegetation provide good habitat that offers potential breeding
areas for different birds, including those that are sedentary (e.g. brown treecreeper, Fig. 5.12),
dispersive (e.g. red-tailed black cockatoo, Fig. 5.13), and migratory (e.g. rainbow bee-eater,
Fig. 5.14).
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Figure 5.12
The brown treecreeper (Climacteris picumnus), listed as vulnerable under the
NSW TSC Act, is a sedentary bird that may reside at Yarrie Lake Flora and Fauna Reserve
These birds forage for insects under the bark of trees, on fallen logs and on the ground.
Figure 5.13
The glossy black cockatoo (Calyptorhynchus lathami) is a dispersive bird, moving
regularly to find food and potential habitat
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Figure 5.14
The beautiful rainbow bee-eater (Merops ornatus) is a migratory bird that
frequents southern parts of Australia during the summer season, to nest
Yarrie Lake contains vegetation which relates back to Gondwanaland hundreds of millions of
years ago. Gondwanaland was a supercontinent made up up of a range of modern day
continents including Australia, South America and Africa. Rulingia procumbens a small
shrub found in this region is relatd to similar plants (of the same genus) found in Madagascar,
off the east African coast. Go to A Brief History of the Namoi to find out more about this part
of Australia’s heritage. Research other plants and animals which relate to the Gondwana era.
Remnant vegetation is important in maintaining biodiversity of ecosystems. Diverse
ecosystems maintain robust food webs that are of value to grazing and cropping enterprises
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and society in general. Micro bats live under tree bark and in the hollows of old trees. The
micro bats that thrive here play a major part in keeping down the numbers of flying insects,
including the mosquitoes that can carry Ross River virus, a disease which can be lethal to
people. Improving remnant vegetation improves the resilience of these foods webs which in
turn improve the resilience of human communities.
Figure 5.15
Corben’s long-eared bat (Nyctophilus corbeni)
One of the predators of night time flying insects.
Barking owls and other predators are important in vermin maintenance. They are excellent
mouse managers and are thus extremely valuable to graziers and croppers, helping to reduce
the impact of small vermin on profits. Barn owls require trees with hollows for roosting in.
Hollows form when mature trees drop large limbs, taking some heartwood with them. Large
hollows are found in trees over 100 years old (Figs. 5.6 and 5.7, above). Without old trees,
these desirable predatory birds are lost.
Wedge-tailed eagles found here are also successful hunters of vermin. . Once blamed for
taking lambs, eagles actually prefer rabbits, wallabies and joeys, so they can actually help us
to manage rabbits. Some people are now taking advantage of the environmental services
which a natural food web brings. When mining companies, such as Werris Creek Coal, are
rehabilitating an area by planting trees, they erect tall dead trees before they start planting.
Eagles occupy the dead trees and hunt rabbits that would otherwise eat the freshly planted
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trees and grass on rehabilitation sites. By reducing rabbit numbers, eagles help to improve the
success of tree plantings.
The ecosystem services provided by the biodiversity of mature diverse remnant areas such as
Yarrie Lake helps to make neighbouring agricultural land more productive, and improves the
health and resilience of communities such as nearby Narrabri and Wee Waa. Remnant
woodland areas such as Yarrie Lake also have recognised benefits as windbreaks, reducing
moisture loss from grazing and cropping enterprises. Farm-design specialists are increasingly
adapting these principles to benefit agricultural production (Curtis 1994).
Threatened animals recorded locally include the corben’s long-eared bat, little pied bat,
barking owl (Fig. 5.16), glossy black-cockatoo, grey-crowned babbler, yellow-bellied
sheathtail-bat (Fig. 5.17) and the pale-headed snake (Fig. 5.18). Brigalow is the preferred
habitat of the endangered black-striped wallaby, which is known to occur in remnants nearby,
and probably occurs within the Yarrie Lake Reserve.
Figure 5.16
The nocturnal barking owl (Ninox connivens) is listed as vulnerable under the
NSW TSC Act
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Figure 5.17
The yellow-bellied sheathtail-bat (Saccolaimus flaviventris) is listed as vulnerable
under the NSW TSC Act; it inhabits tree hollows during the daytime
Figure 5.18
The threatened pale-headed snake (Hoplocephalus bitorquatus) has been
recorded for the Yarrie Lake Reserve
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Exotic animals such as the house mouse, domestic dog, fox, cat, brown hare, rabbit and pig
have been recorded at Yarrie Lake.
5.4
Geology and soil of Yarrie Lake Flora and Fauna Reserve
Yarrie Lake is formed by a natural circular depression about 3 km in diameter. Soils at the
reserve include sandy duplex on grey clay, sandy soils supporting woodland, and hard-setting
clay supporting Brigalow. The lake bed comprises grey clay, which explains the milky look of
the water within the lake.
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5.5
References
ABC (2009). Breakfast with Anna Moulder: The Yarrie Lake mystery.
http://blogs.abc.net.au/nsw/2009/02/the-yarrie-lake.html accessed 10 March 2013.
Curtis D (1994). Seven ways to shelter a paddock. Greening Australia Field Notes, Armidale.
DSEWPAC (2012). Species profile and threats (SPRAT) database: Brigalow (Acacia
harpophylla dominant and co-dominant). Department of Sustainability, Environment, Water,
Population and Communities. http://www.environment.gov.au/cgibin/sprat/public/publicshowcommunity.pl?id=28 accessed 8 march 2013.
OEH (no date). Grassy Brigalow within the Brigalow Belt South, Nandewar and Darling
Riverine Plains Bioregions – profile. NSW Office of Environment and Heritage.
http://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10109 accessed 8
March 2013.
OEH (2012). Threatened ecological communities. NSW Office of Environment and Heritage.
http://www.environment.nsw.gov.au/threatenedspecies/hometec.htm accessed 8 March 2013.
McKemey M and White H (2011). Bush tucker, boomerangs and bandages: Traditional
Aboriginal plant use in the Border Rivers and Gwydir Catchments. Border Rivers-Gwydir
Catchment Management Authority, NSW.
Namoi CMA (2013). A Brief History of the Namoi. Namoi Catchment Management Authority
http://www.namoi.cma.nsw.gov.au/672447.html Accessed 26 July 2013
Nash D (2004). Aboriginal plant use in south-eastern Australia. Education Services,
Australian National Botanic Gardens, ACT.
http://www.anbg.gov.au/gardens/education/programs/Aboriginal-plantuse.pdf accessed 2
April 2013.
Ward WT (1999). Soils and landscapes near Narrabri and Edgeroi, NSW, with data analysis
using fuzzy k-means. CSIRO Land and Water Technical Report 22/29 July. CSIRO, Canberra.
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Appendix 5.1 Threatened and migratory species recorded for the Narrabri region, which may
occur at Yarrie Lake Flora and Fauna Reserve
* Identifies species known to occur
Common name
Scientific name
Plants (flora)
Rulingia procumbens
Commonwealth
status
EPBC Act
E = endangered
V = vulnerable
M = migratory
V
V
NSW
status
TSC Act
Belson's panic
Homopholis belsonii
E
V
Bluegrass
Dichanthium setosum
V
V
Coolabah bertya
Bertya opponens
V
V
Creeping tick-trefoil
Desmodium campylocaulon
E
Finger panic grass
Digitaria porrecta
E
E
Greenhood orchid
Pterostylis cobarensis
V
V
Large-leafed monotaxis
Monotaxis macrophylla
E
Native milkwort
Polygala linariifolia
E
Pine donkey orchid
Diuris tricolor
V
Scant pomaderris
Pomaderris queenslandica
E
Scrambling lignum
Muehlenbeckia costata
V
Sedge
Cyperus conicus
E
Shrub sida
Sida rohlenae
E
Slender darling pea
Swainsona murrayana
V
V
Slender tylophora
Tylophora linearis
V
E
Spiny peppercress
Lepidium aschersonii
V
V
Australasian bittern
Botaurus poiciloptilus
E
E
Australian bustard
Ardeotis australis
E
Australian painted snipe
Rostratula australis
E
Barking owl*
Ninox connivens
V
Black-breasted buzzard – predicted
Hamirostra melanosternon
V
Black-chinned honeyeater
Melithreptus gularis gularis
V
Black-necked stork
Ephippiorhynchus asiaticus
E
Black-tailed godwit
Limosa limosa
V
Blue-billed duck
Oxyura australis
V
Brolga
Grus rubicunda
V
Brown treecreeper
Climacteris picumnus victoriae
V
Animals (fauna)
Birds
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V
M
Bush stone-curlew
Burhinus grallarius
E
Diamond firetail
Stagonopleura guttata
V
Freckled duck
Stictonetta naevosa
V
Glossy black-cockatoo*
Calyptorhynchus lathami
V
Grey-crowned babbler*
Pomatostomus temporalis temporalis
V
Hooded robin
Melanodryas cucullata cucullata
V
Latham's snipe
Gallinago hardwickii
Little eagle
Hieraaetus morphnoides
V
Little lorikeet
Glossopsitta pusilla
V
Magpie goose
Anseranas semipalmata
V
Masked owl
Tyto novaehollandiae
V
Painted honeyeater
Grantiella picta
V
Rainbow bee-eater
Merops ornatus
Red-tailed black-cockatoo
Calyptorhynchus banksii samueli
V
Speckled warbler
Chthonicola sagittata
V
Spotted harrier
Circus assimilis
V
Square-tailed kite
Lophoictinia isura
V
Superb parrot
Polytelis swainsonii
V
V
Swift parrot
Lathamus discolor
E
E
Turquoise parrot
Neophema pulchella
V
Varied sittella
Daphoenositta chrysoptera
V
White-throated needletail
Hirundapus caudacutus
M
M
M
Mammals
Black-striped wallaby
Macropus dorsalis
E
Corben's long-eared bat*
Nyctophilus corbeni
V
V
Koala
Phascolarctos cinereus
V
V
Little pied bat*
Chalinolobus picatus
V
Spotted-tailed quoll
Dasyurus maculatus
V
Squirrel glider
Petaurus norfolcensis
V
Yellow-bellied sheathtail-bat*
Saccolaimus flaviventris
V
Five-clawed worm-skink
Anomalopus mackayi
E
Pale-headed snake*
Hoplocephalus bitorquatus
V
E
Reptiles
EPBC Act, Commonwealth Environment Protection and Biodiversity Conservation Act 1999
TSC Act, NSW Threatened Species Conservation Act 1995
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V