Pacific Highway Upgrade – Ecology Update
Niche Environment and Heritage was engaged by Roads and Maritime Services to undertake ecological monitoring services for the Pacific Highway upgrade between Port Macquarie and Eungai. This major upgrade project improves highway safety, reduces travel times and improves local access.
As part of the ecological monitoring for this project, our locally-based Port Macquarie ecology team has been carrying out monitoring of the threatened Giant Barred Frog (Mixophyes iteratus), pictured above.
The project is jointly funded by the Australian and NSW governments.
Monitoring of this species involves nocturnal surveys along transects that follow creeks traversing the highway. As part of the monitoring program, Niche ecologists have been PIT tagging captured individuals and recording their capture location. Recapture data is therefore available to determine movements of recaptured individuals.
Effect of large road corridors
An analysis of the data by Niche ecologist Dr Radika Michniewicz showed that a proportion of recaptured Giant Barred Frogs had traversed under the highway from one side of the carriageway to the other on at least one occasion.
While the monitored waterways continue uninterrupted under the carriageway, there is a distinct reduction in, or absence of, streamside vegetation within the area immediately under the carriageway that may be considered as a potential barrier to movement.
Despite this abrupt change in streamside habitat immediately under the carriageway, 21%- 44% of recaptured Giant Barred Frogs traversed the carriageway on at least one occasion.
This result is important when discussing the potential barrier effect of large road corridors on the movement of this species and the performance of mitigation and management measures.
Other noteworthy results of the Oxley Highway to Kempsey and Frederickton to Eungai Pacific Highway Upgrade monitoring programs undertaken by Niche include:
- Photographic record of the use of a combined drainage culvert/fauna underpass by the threatened Spotted-tailed Quoll (Dasyurus maculatus)
- Photographic record of the use of installed glider poles by the threatened Yellow-bellied Glider (Petaurus australis)
- Evidence of use of a widened median by a number of glider species, including the Feathertail Glider (Acrobates pygmaeus) and Sugar Glider (Petaurus breviceps)
- Use of installed nest boxes by threatened species including Yellow-bellied Gliders, Squirrel Gliders (Petaurus norfolcensis) and Brush-tailed Phascogales (Phascogale tapoatafa)
- Confirmed presence of the threatened Brush-tailed Phascogale in State Forest immediately adjacent to the Upgrade.
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