Birds and wet eucalypt forest succession

Project name:	Birds and wet eucalypt forest succession
Year started:	1997
Project number:	WRA034
Primary investigator:	Andrew Hingston
Other investigator(s):
Enquiries:	warra.enquiries@forestrytas.com.au
Organisation(s):	Forestry Tasmania
Project type:	Professional
Project status:	Completed

Project summary:

Bird assemblages were documented in different forest types in the Warra Long Term Ecological Research site in Tasmania’s southern forests. Sampling was undertaken in areas immediately after clearfelling and burning, in regrowth up to 26 years after this treatment, selectively logged forest, regrowth following wildfire, and old-growth forest. It was found that areas subjected to clearfelling and burning supported assemblages which were distinct from areas with other histories, in that they comprised fewer species and individuals. This adverse impact of silvicultural practices on bird populations was apparent in all strata of the forest: canopy, mid-layer and ground.

Immediately after clearfelling and burning, coupes were colonised by ground-feeding insectivores more typical of open country than the surrounding wet sclerophyll forests. These species were quickly displaced in young regrowth, which was gradually colonised by forest-inhabiting species. However, these assemblages were still depauperate as much as 26 years after logging. Comparisons with previous studies suggest that this deleterious impact of forestry operations on birds may be ameliorated by the retention of trees in logging coupes. This is supported by the absence of significant impacts on birds in areas which were selectively logged 25 years ago.

These are the other bird projects undertaken at Warra:

WRA046 Bird succession in the Warra SST.

WRA068 Bird monitoring along an altitudinal transect on Mount Weld.

WRA104 Development and implementation of standardised bird surveys in wet eucalypt forest at Warra.

Methodology:

Birds were surveyed between March and May 1998. Surveys were restricted to fine days with little wind or rain. This involved two separate studies:

1) transects in the Silvicultural Systems Trial area on Manuka Rd between 8 March and 6 April; and

2) spot surveys of 15 minutes duration in areas with different vegetation types and silvicultural histories on Warra Rd and South Weld Rd between 7 April and 28 May.

An assessment of audiotaping as a means of surveying birds was also conducted at some of the sites on Warra Rd and South Weld Rd. Golden Whistlers and Olive Whistlers were combined in the data analysis as their calls were not distinguished by the observer.

All birds seen or heard were noted while walking along the cut tracks, with each track being broken into sections according to distance markers along them. All birds seen or heard in each of these sections were recorded as being present in that section, unless it was certain that an individual had been recorded in the previous section (in which case it was ignored in the second section). The days were divided into five periods of two hours each, with every track being surveyed at least once in each time period.

Datasets:

None available.

Publications:

Hingston, A. (2000). Impacts of logging on autumn bird populations in the southern forests of Tasmania. Papers and Proceedings of the Royal Society of Tasmania 134: 19-28.