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Rangeland ecology and management

The effects of vegetation structure on the birds in a tropical savanna woodland in north-eastern Australia

A. L. Tassicker A B , A. S. Kutt B C , E. Vanderduys B and S. Mangru B
+ Author Affiliations
- Author Affiliations

A School of Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.

B CSIRO Sustainable Ecosystems, Rangelands and Savannas, Davies Laboratory, PMB PO, Qld 4814, Australia.

C Corresponding author. Email:

The Rangeland Journal 28(2) 139-152
Submitted: 23 August 2005  Accepted: 19 December 2005   Published: 9 November 2006


Management of the dynamics of woody vegetation in Australia’s tropical savannas is a vexing issue for both pastoralists and conservation biologists. In savanna regions around the world, increasing density of woody vegetation contributes to declines in pastoral productivity, but its effects on native fauna are largely unknown. In this paper we examine the avifauna in savanna woodlands of varying structure in the Desert Uplands bioregion, Queensland. Vegetation cover maps derived from aerial photographs were used to choose 60 sites, across 4 cattle stations. We sampled sites mapped at 30–45% and 45–60% foliage cover, and areas which previously had these levels of cover but had been mechanically modified, both by broad scale clearing and selective thinning. Between May and June 2004, we measured a range of habitat variables and sampled the birds at each site. Bird species composition varied significantly between treatments. Bird richness and frequency was greatest in intact vegetation. Thirteen species of birds were most frequently encountered in sites with 30–45% canopy cover, compared with 10 species in the 45–60% cover sites, 4 species in the thinned sites and 7 in the cleared sites. Our results suggest that increasing density of woody vegetation in savanna woodland may be to the advantage of some savanna bird species. Mechanical modification to reduce woody vegetation appears to also benefit some common, widespread species, but has a generally negative overall effect on bird species richness.

Additional keywords: avian species richness, clearing, composition, thickening, thinning.


We are grateful for the help of numerous landholders in granting us access to their properties and explaining their management practices, past and present: the Bode’s (Woura Park and Timaru), Haydon’s (Penrice) and Merten’s (Kalleroo). Felicity Adams and Maz Wong provided valuable assistance in the field. AT thanks Professor Chris Johnson (James Cook University) for excellent project supervision. John Woinarski (NT Department of Natural Resources, Environment and the Arts) and 2 anonymous reviewers improved the manuscript with their comments. This project was funded by the Tropical Savannas CRC, and operational support provided by James Cook University and the Queensland Environmental Protection Agency.


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1Botanical nomenclature according to Queensland Government (2003).

Appendix 1. Species guild membership (used in Table 4), after Fisher (2001) and Kutt (2004)

Aerial insectivore (AI)

Australian owlet-nightjar Aegotheles cristatus

Black-faced woodswallow Artamus cinereus

Grey fantail Rhipidura fuliginosa

Jacky winter Microeca fascinans

Little woodswallow Artamus minor

Masked woodswallow Artamus personatus

Restless flycatcher Myiagra inquieta

White-browed woodswallow Artamus superciliosus

Aquatic (AQ)

White-necked heron Ardea pacifica

Foliage insectivore (FI)

Black-faced cuckoo-shrike Coracina novaehollandiae

Brown treecreeper Climacteris picumnus

Buff-rumped thornbill Acanthiza reguloides

Grey shrike-thrush Colluricincla harmonica

Inland thornbill Acanthiza apicalis

Pallid cuckoo Cuculus pallidus

Rufous whistler Pachycephala rufiventris

Striated pardalote Pardalotus striatus

Varied sittella Daphoenositta chrysoptera

Weebill Smicrornis brevirostris

Western gerygone Gerygone fusca

White-bellied cuckoo-shrike Coracina papuensis

White-throated gerygone Gerygone olivacea

White-winged triller Lalage sueurii

Yellow-rumped thornbill Acanthiza chrysorrhoa

Foliage insectivore/nectarivore (FIN)

Blue-faced honeyeater Entomyzon cyanotis

Grey-fronted honeyeater Lichenostomus plumulus

Little friarbird Philemon citreogularis

Noisy friarbird Philemon corniculatus

Singing honeyeater Lichenostomus virescens

Spiny-cheeked honeyeater Acanthagenys rufogularis

Striped honeyeater Plectorhyncha lanceolata

White-plumed honeyeater Lichenostomus penicillatus

White-throated honeyeater Melithreptus albogularis

Yellow-throated miner Manorina flavigula

Frugivore (FR)

Mistletoebird Dicaeum hirundinaceum

Spotted bowerbird Chlamydera maculata

Ground insectivore (GI)

Crested bellbird Oreoica gutturalis

Grey-crowned babbler Pomatostomus temporalis

Ground cuckoo-shrike Coracina maxima

Hooded robin Melanodryas cucullata

Magpie-lark Grallina cyanoleuca

Rufous songlark Cincloramphus mathewsi

Willie wagtail Rhipidura leucophrys

Variegated fairy-wren Malurus lamberti

Ground insectivore/granivore (GIG)

Singing bushlark Mirafra javanica

Ground insectivore/omnivore (GIO)

Apostlebird Struthidea cinerea

Australian bustard Ardeotis australis

Australian magpie Gymnorhina tibicen

Emu Dromaius novaehollandiae

Granivore (GR)

Bar-shouldered dove Geopelia humeralis

Brown quail Coturnix ypsilophora

Budgerigar Melopsittacus undulatus

Cockatiel Nymphicus hollandicus

Common bronzewing Phaps chalcoptera

Crested pigeon Ocyphaps lophotes

Double-barred finch Taeniopygia bichenovii

Galah Cacatua roseicapilla

Little button-quail Turnix velox

Pale-headed rosella Platycercus adscitus

Painted button-quail Turnix varia

Peaceful dove Geopelia striata

Red-winged parrot Aprosmictus erythropterus

Sulphur-crested cockatoo Cacatua galerita

Zebra finch Taeniopygia guttata

Nectarivore (NE)

Brown honeyeater Lichmera indistincta

Rainbow lorikeet Trichoglossus haematodus

Scaly-breasted lorikeet Trichoglossus chlorolepidotus

Raptore (RA)

Black-breasted buzzard Hamirostra melanosternon

Blue-winged kookaburra Dacelo leachii

Brown falcon Falco berigora

Brown goshawk Accipiter fasciatus

Collared sparrowhawk Accipiter cirrhocephalus

Crow/raven Corvus sp.

Grey butcherbird Cracticus torquatus

Nankeen kestrel Falco cenchroides

Pied butcherbird Cracticus nigrogularis

Red-backed kingfisher Todiramphus pyrrhopygia

Tawny frogmouth Podargus strigoides

Wedge-tailed eagle Aquila audax

Whistling kite Haliastur sphenurus

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