Biodiversity publications archive

Refugia for biological diversity in arid and semi-arid Australia

Biodiversity Series, Paper No. 4
S.R. Morton, J. Short and R.D. Barker, with an Appendix by G.F. Griffin and G. Pearce
Biodiversity Unit
Department of the Environment, Sport and Territories, 1995

6. Foci of biological diversity in the Northern Territory (continued)

6.5. Tanami

Area

292,194 km².

Primary land-use

Aboriginal use, mining, cattle grazing.

National Parks and Nature Reserves

Devil's Marbles Conservation Reserve. There are proposed reserves within the Davenport and Murchison Ranges.

Management problems

Land degradation due to over-grazing by cattle (Wilcox and Cunningham 1994). Fire management in the spinifex country is a major issue (Pearson 1991).

Rabbits are widespread but uncommon, (and are absent from the northern Tanami); foxes are probably rare but can still damage relict populations, cats are common; horses and donkeys (rare); camels (widespread but uncommon) (Gibson 1986).

In the Davenport and Murchison Ranges cats are present, donkeys locally common, rabbits uncommon, and cattle occasionally concentrated. The area has high potential for both severe and widespread wildfires.

ANZECC-listed species

Mammals: Rufous hare-wallaby Lagorchestes hirsutus (E) is rare and localised; the bilby Macrotis lagotis (V) is widespread and abundant relative to elsewhere in its range; the mulgara Dasycercus cristicauda (V) is also common in some locations; black-footed rock-wallaby Petrogale lateralis (V) is rare and restricted (Johnson et al.1984; Gibson 1986, pp. 125-35; Gibson and Cole 1992).

Birds: Alexandra's parrot Polytelis alexandrae (V) was not recorded by Gibson 1986, but birds were collected in 1965 and five birds seen on Mt Doreen Station in 1967 (Parker 1969 in Gibson 1986).

Plants: The water plant Rhamphicarpa australiensis in the Davenport and Murchison Ranges (Johnson et al. 1984).

Species that are regionally endemic

Johnson's mouse Pseudomys johnsoni is endemic to rocky country (primarily in the Murchison Range) in this Region (Kitchener 1985). The skink Ctenotus tanamiensis and the frog Uperoleia micromeles (Gibson 1986) are confined to the Tanami Desert.

Five plants are restricted to the Davenport and Murchison Ranges: Fimbristylis sp., Acacia sp., Acacia aff. hemsleyi, Tephrosia sp. and Wedelia aff. stirlingii; several are likely to be endemic.

"Plants more or less restricted to the Northern Tanami region" (particularly the Lake Surprise dunefield; Latz 1988) are Acacia jensenii, Pimelea ammocharis, Sauropus hunti, and Eucalyptus aff. setosa.

Relict populations

One relict plant species is recorded from the Davenport and Murchison Ranges, but was not named (Johnson et al. 1984). The rufous hare-wallaby has retreated to the Region, and significant populations of the bilby and mulgara exist there.

The great desert skink Egernia kintorei occurs uncommonly in the Region (Gibson 1986; Cogger et al. 1993, pp. 88-90).

Other significant populations

The Tanami Desert "is one of the most important biological areas to be found in Australia particularly as it provides refuge for several of Australia's rare and endangered species" (Gibson 1986, p. 79). It contains several relict species of mammals, and notable limits of the ranges of others such as western chestnut mouse Pseudomys nanus, delicate mouse Pseudomys delicatulus, and long-tailed planigale Planigale ingrami. Significant bird species include grey falcon Falco hypoleucos, painted snipe Rostratula benghalensis and freckled duck Stictonetta naevosa (Gibson 1986, p. 164). Particularly significant to the relict species is the buried drainage system which runs through a sandplain of feathertop spinifex Plectrachne schinzii for up to 50 km to the south of The Granites. The system is some metres lower than this sandplain, and supports other spinifexes Triodia pungens and Plectrachne sp., plus a variety of halophytic plants – Hemichroa diandra, Eragrostis falcata, Neobassia astrocarpa and Halosarcia halocnemoides – around saline pans (Gibson 1986; Lundie-Jenkins 1993; Lundie-Jenkins et al. 1993).

The Davenport and Murchison Ranges possess an "extensive network of waterholes...[and are]...most probably an important drought time refuge for waterbirds"; "the presence of 7 species of fish in two catchments [Whistleduck Creek and Frew River; Leiopotherapon unicolor, Ambassis agrammus, Nematolosa erebi, Mogurnda mogurnda, Melanotaenia splendida tatei, Amniataba percoides] which are isolated from any other major river system gives the area considerable zoogeographical importance" (Johnson et al. 1984). In addition, there are several rare plant species, and high plant diversity springs from an overlap of Central Australian and Barkly Tableland floras (Fleming et al. 1983). The four most important rare species are Rhamphicarpa australiensis (a tropical waterplant), Trachymene inflata, Acacia aff. aneura (distinctive 'Christmas tree' shape), and Psoralea walkingtonii. Others are Brachyachne prostrata, Elacholoma hornii, Glycine aff. tomentella, Hedyotis sp., Phyllanthus aff. simplex, Triumfetta plumigera, and Vernonia cinerea. Nevertheless, "in comparison with similar areas of Central Australia such as the George Gill and Petermann Ranges the Murchison/Davenport block contains few rare, relict or endemic plants" (Johnson et al. 1984). There are no rare or endangered bird species although two species require unburnt spinifex (striated grasswren Amytornis striatus and spinifex bird Eremiornis carteri).

The Lake Surprise dunefield area of the Tanami Desert contains three rare plants (Olax spartea, Comesperma ?pallidum, and Atriplex sp.) and at least five plant species which represent significant range extensions (Latz 1988).

Wetland sites

Lake Surprise (Northern Territory) is the terminus of the Lander River, and represents a major drought refuge for waterbirds in a Region largely devoid of large waterbodies (Gibson 1986; Fleming 1993).

Lake Gregory (Western Australia) retains some surface water permanently and is the only lake in this region and in the deserts to the south to do so. The Lake is fresh when full. Seventy waterbird species have been recorded, sometimes in vast numbers; more than 100,000 occur regularly, and perhaps as many as 600,000 occasionally (Jaensch and Vervest 1990). Prominent among the birds are migratory waders, which utilise the Lake as a stopover. There are numerous invertebrates, some of which appear to be undescribed (Fleming 1993). Concerns have been expressed about potentially damaging grazing by cattle (Fleming 1993).

Refugia

Lake Gregory (see section 10.12), Lake Surprise (12.4), the Davenport and Murchison Ranges (12.7), and the Tanami drainage system near The Granites (12.13) appear to constitute refugia.