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Brown Treecreeper Reintroduction

 

Scientific name: Climacteris picumnus
Conservation status in NSW: Vulnerable

The Brown Treecreeper is Australia’s largest treecreeper. It is a grey-brown bird with black streaking on the lower breast and belly and black bars on the undertail. It's face is pale, with a dark line through the eye and a dark crown.

Distribution
The Brown Treecreeper is endemic to eastern Australia and occurs in eucalypt forests and woodlands of inland plains and slopes of the Great Dividing Range. It is less commonly found on coastal plains and ranges.

Habitat and ecology
Found in eucalypt woodlands, like Box-Gum Grassy Woodlands, and dry open forest, mainly dominated by stringybarks or other rough-barked eucalypts (such as yellow box). Brown treecreepes live in social groups comprising of the breeding pair, helper offspring that have delayed dispersal and fledglings. They forage on trunks and branches of trees, amongst fallen timber, and spend much more time foraging on the ground and fallen logs that other treecreepers. Up to 80% of their diet is comprised of ants, with other invertebrates making up the rest of their diet. They nest in hollows and used hollow logs for shelter from predators.

Threats
The brown treecreeper disappeared from Mulligans Flat in 2000 and Goorooyarroo in 2005. Known threats include:

Research Project

This project will complete the first experimental reintroduction of the Brown Treecreeper, Climacteris picumnus. The species is being reintroduced into both Mulligans Flat and Goorooyarroo Nature Reserves. This is being conducted using populations sourced from Murrumbidgee region southeast of Wagga Wagga, NSW. By preforming this reintroduction with a rigorous experimental framework with a detailed monitoring plan, we will not only hope to re-establish an iconic declining woodland species population, we will also test habitat selection theories that underpin reintroductions, develop protocols to guide bird reintroductions in many Australian environments and improve our understanding of the conditions required for the persistence and recovery of the brown treecreeper.

Reintroduction Process
Seven family groups of brown treecreepers were reintroduced into Mulligans Flat and Goorooyarroo Nature Reserves during November and December 2009. The birds were release in family groups, including dependent fledglings, to promote site fidelity and group cohesion. Individuals within a group remained mostly together with the exception of some male helpers and female breeders that dispersed to explore other areas, however most individuals returned to their group of origin. Survival has been slightly lower than expected, partly due to higher than normal predation rates. However, it is probable that actual survival is higher than the estimated survival due to difficulties in locating birds that have separated from thier groups.

Territory-scale habitat information and bird movement
We will examine whether we can use basic ecological information form studies in remnant sites to identify key habitat attributes that will be selected by brown treecreepers in restored environments. We will examine the movement paths of radio-tracked birds to determine how they actively search and select habitat as well as the location and size of thier territory once it is established. Close monitoring of individuals will enable us to assess the quality of the habitat they select and any potential relationship with survival.

Small-scale habitat quality
Monitoring of release brown treecreepers involved taking regular observations of behaviour and substrate use of radio-tracked individuals. We want to know whether we can analyse the behaviour and habitat use of reintroduced birds to inform us about habitat quality and the effectiveness of restoration actions. For example, based on previous research we would expect that areas with a grassier ground layer would provide fewer opportunities for high-quality ground-based foraging and may also be more difficult for brown treecreeper to manoeuvre through to escape predators. Therefore, we would anticipate that brown treecreepers would be observed foraging more often on the ground in areas with low levels of vegetation ground cover.

Predation rates of released Brown Treecreepers
Monitoring of the released birds detected a predation rate higher than the normal adult death rates that have been observed through extensive research on the source population. This suggests that predation by native predators maybe the primary impediment ot the successful establishment of a brown treecreeper population. Although high predation rates may be, to some extent, a consequence of the reintroduction process, the rates may also inform us about the suitablility of the restored habitat at the release sites and the indirect effects that habitat may have on populations. We will examine whether higher predation rate may be due to a higher density of native predators, a reduced density of suitable refuge areas, a consequence of the reintroduction process, or a reduction of individual condition (or a combination of these factors).

Ongoing Research

Released brown treecreepers are monitored monthly for survival and reproductive activity. Analysis of predation rates of released brown treecreepers is yet to be conducted in the field.

Funding and support sources:

This project has also been dependent upon numerous excellent volunteers based both in Canberra and Wagga Wagga. Their help is greatly appreciated.

Publications

 

More information contact ANU Research Officer.

 

Mulligans Flat Goorooyarroo Woodland Experiment Contact Details