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Australasian Plant Conservation

Originally published in Australasian Plant Conservation 22(2) September - November 2013, p 14-15

Restoring reserves in the heart of Western Sydney: habitat reconstruction for the threatened Scarlet Robin

Chantelle Doyle1*, Chris Macris1, Aimee Freemanis2
1Greening Australia NSW 2Parramatta City Council
*Corresponding author email: cdoyle@greeningaustralia.org.au


Top: Collecting and transporting logs. Bottom: Log installation. Levelling in prepared areas. Photos: Chris Macris

Grassy log pile in Area A. Photo: Chantelle Doyle

Introduction

Greening Australia, Parramatta City Council and Cumberland Bird Observers Club collaborated on a small but significant restoration initiative to restore foraging habitat for woodland bird species recorded in a refugia within Western Sydney. The works sought not only to establish immediate foraging habitat for a poorly understood and threatened bird species, the Scarlet Robin (Petroica boodang), but likewise provide some insight as to its and other woodland birds’ ecological requirements. Works undertaken involved creation of foraging ‘islands’ to meet the niche seasonal foraging patterns of Scarlet Robin and more generally the diverse requirements of a suite of small insectivorous woodland birds. The islands included three treatments: log piles with shrubs, log piles with grasses and log piles with no accompanying vegetation. Additional scattered canopy species and shrubs were planted to create ‘stepping stones’ and close large gaps in the formerly open pasture.

Background

The State of Australia’s Birds Report 2009 suggests that 50% of woodland birds could be extinct by 2050. Urban remnants and refuges play an increasingly important role in reducing biodiversity loss and providing habitat for diverse species within a city environment. Waddangalli Woodland is one such remnant. It is a 14.7 ha reserve zoned as E2 Environmental Conservation Zone (DOP, 2009) occurring within Parramatta Local Government Area (LGA), in Western Sydney. The area had been actively farmed since the mid 1900s and is currently managed by Parramatta City Council. The site includes restoration and regeneration zones of mixed remnant Cumberland Plain Woodland (an endangered ecological community) and cleared pastures (7.4 ha), along with unmanaged dense woody weed infestations (8.3 ha). A single site inspection in October 2012 detected 36 bird species including two unusual species not recorded commonly in urban habitat, the Satin Flycatcher (Myiagra cyanoleuca) and a juvenile White-bellied Cuckoo shrike (Coracina papuensis). These two woodland dependent species, along with instances of Scarlet Robin recorded in Parramatta Snapshot Fauna Surveys Report 2012 suggest this reserve provides valuable bird habitat in the Parramatta LGA and could be utilised by many other declining woodland bird species (e.g. Varied Sittella (Daphoenositta chrysoptera)) as an urban refuge and for seasonal movements across the Sydney region.

Many woodland bird species have specific spatial attribute requirements including patch sizes of 10-100 ha, large compact woodland (as opposed to narrow corridors) and a varied landscape matrix of mixed age trees, open grasslands to dense shrubs and accessible logs and branches for perching and foraging. Although this description focuses largely on the habitat requirements of the Scarlet Robin the attributes of the site and restoration design support an array of insectivorous species of woodland birds.

Scarlet Robin is an altitudinal migrant, which forms monogamous pairs. It feeds on invertebrates and has variable foraging, which occurs both at the ground layer (pouncing) and in open air (snatching and hawking) (Major, 2013; Miller, 2013; Robinson, 1992). Some research suggests foraging patterns are seasonal, with snatching and hawking occurring in warmer months (Robinson, 1992) and requiring open woodland and grassland. Pouncing by contrast is suggested to require tree forks, low shrubs and branches for perching, with ground foraging occurring amongst logs and coarse woody debris (OEH, 2010).

Methods

From May to July 2013, Greening Australia staff worked in collaboration with Parramatta City Council to install foraging habitat in two cleared areas (Zone A and Zone B) dominated by exotic pasture grasses (primarily African Love Grass: Eragrostis curvula). A total of 1.6 ha of cleared area was revegetated using 2250 planted Cumberland Plain grasses, 120 shrubs and 40 canopy species.

All shrubs and canopy species of local provenance and grown by the Parramatta City Council community nursery. Grasses were supplied by Greening Australia’s Richmond production nursery and were Cumberland Plain provenance. Species included:

  • Grasses: Themeda triandra in six, five metre diameter circles
  • Shrubs: Bursaria spinosa, Dillwynia sieberi, Acacia linearifolia, Melaleuca thymifolia and Indigofera australis installed amongst logs islands and in clusters of four to create stepping stones through the area
  • Trees: Eucalyptus longifolia and Eucalyptus fibrosa. Scattered at 5-10 metre spaces through Zones A and B.

In addition to revegetation, 72 logs of varying sizes up to 700 kg were installed as a series of islands. Logs were all sourced from Western Sydney, had bark intact and were frequently in early stages of decomposition, to encourage invertebrate colonisation.

The log islands had three unique treatments, replicated four times each across the two restoration zones. These were:

  • logs in close proximity to open areas (four in total, three in Zone A and one in Zone B)
  • logs in close proximity to grass patches (four in total, three in Zone A and one in Zone B)
  • logs in close proximity to one by one metre shrubby quadrats (four in total, three in Zone A and one in Zone B).

Additionally, star pickets were installed in both zones to act as false perches - fast tracking opportunities for woodland bird species who exhibit pouncing foraging.

Conclusions

Given most of the information about Scarlet Robin foraging comes from studies of populations on the northern tablelands, the preferences of individuals using this reserve were unknown. Habitat islands were therefore designed to facilitate monitoring of preferred foraging conditions and will provide answers informing future habitat reconstruction works which will achieve 10 ha of connected habitat within the site. Long term monitoring of the site is being conducted by Cumberland Bird Observers Club in association with Parramatta City Council to record bird sightings in the area and to identify any preferential foraging patterns of woodland species. Information gleaned from this study will not only be used to inform future habitat restoration works in Western Sydney but may likewise be of benefit in guiding the direction and method of similar programs conducted as part of restoration and regeneration programs across Australia. It is hoped that this project will set a precedent for the benefits of carrying out highly informed restoration initiatives with clearly quantifiable ecological outcomes.

Acknowledgements

Our thanks to the Natural Resources Team at Parramatta City Council and the Cumberland Bird Observers Club who supported the initiation and ongoing monitoring of the project.

References

Barrett, G.S.A. (2003). The new atlas of Australian birds. RAOU, Melbourne.

Debus, S. (2006). Breeding and population parameters of robins in a woodland remnant in northern New South Wales, Australia. Emu, 106, 147-156.

Office of Environment and Heritage (2010). Scarlet Robin Petroica boodang (Lesson 1838) - vulnerable species listing: New Scientific Committee - final determination. NSW Government. http://www.environment.nsw.gov.au/determinations/scarletrobinFD.htm

Robinson D, (1992). Habitat Use and Foraging Behaviour of The Scarlet Robin and The Flame Robin at a Site of Breeding-season Sympatry. Wildlife Research 19, 377-95

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