What insight does monitoring of arboreal marsupials offer for mitigating road impacts on wildlife?

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1 What insight does monitoring of arboreal marsupials offer for mitigating road impacts on wildlife? Dr Ross Goldingay Wildlife Ecology Program Southern Cross University Lismore, NSW Photo: Karawatha Preservation Society My aim is to briefly review what is known about roads & arboreal marsupials Photo: Karawatha Preservation Society

2 A Reminder of the Challenge Ahead Extreme road-mediated habitat fragmentation. Logan Motorway, south-west Karawatha Forest, se Qld In this landscape 7 spp. arboreal marsupials Are all arboreal marsupials the same?

3 Are all arboreal marsupials the same? I m not incl. semi-arboreal. Brushtail possums Phascogales Tree-kangaroos Pygmy-possums Ringtail possums Gliding possums Koala Do roads comprise a barrier to these species? Can we answer without detailed data? Brushtail possums Phascogales Tree-kangaroos Pygmy-possums Ringtail possums Gliding possums Koala

4 Do they move along the ground in normal activity? Often Sometimes* Often Often Sometimes Often Never Yes Do they move along the ground in normal activity? Often Sometimes* Often Often Sometimes Often Never Yes Basically 2 groups ground-using & ground-avoiding This is also reflected in road-kill data

5 What is the frequency of People-kill? Frequent Frequent* Frequent Sometimes-----Sometimes Rare What is the frequency of road-kill? Frequent Frequent* Frequent Sometimes-----Sometimes Rare If the road-tree-gap is too wide to glide or jump across the road is a barrier to the gliders. Road mitigation is needed for all groups.

6 Does this allow prediction of the crossing structures needed? What options do we have for arboreal mammals? Underpass Land-bridge Land-bridge with glider poles Canopy-bridge

7 What options do we have for arboreal mammals? Bridge underpass And of course Glider poles without the Land-bridge What do monitoring data reveal about use of these structures by arboreal mammals? Using review of van der Ree et al. (2007) & some unpubl. work Brushtails (+++), Ringtails (+), Koala (+), Pygmy-possum (+) Brushtails (+++), Ringtails Ringtails (++), Brushtails (++), Gliders (++), P-P Brushtails (++), Ringtails (+), Koala (+), Gliders (+) Brushtails (+), Gliders (++) No data but

8 What do monitoring data reveal about use of these structures by arboreal mammals? Ball, T. & Goldingay, R. (2008). Can wooden poles be used to reconnect habitat for a gliding mammal? Landscape and Urban Planning 87: No data but Use vs Effectiveness? Behavioural data not ecological Brushtails (+++), Ringtails (+), Koala (+), Pygmy-possum (+) Brushtails (+++), Ringtails Ringtails (++), Brushtails (++), Gliders (++), P-P Brushtails (++), Ringtails (+), Koala (+), Gliders (+) Brushtails (+), Gliders (++) Squirrel Gliders (++)

9 Number of tracks Possums Bandicoots Overpasses Tagget s Hill, Tweed Motorway Tracks in sand per 6 wks 4 yrs after construction Marshall's Ridges Tagget's Hill Number of tracks Underpasses Possums Bandicoots 3 (Hayes & Goldingay unpubl. data) Marshall's Ridges Tagget's Hill Monitoring of poles at Compton Road Compton Road Hair-tube Survey Number of poles with hair Oct-06 Dec-06 Feb-07 Apr-07 Jun-07 Aug-07 Oct-07 North Poles (3) Middle Poles (2) South Poles (3) X = no detection X X X X X X X Dec-07 Feb-08 Apr-08 Jun-08 Aug-08 Oct-08 Dec-08 Feb-09 (Taylor & Goldingay unpubl. data)

10 Basic Summary Implications for ground-using (GU) & ground-avoiding (GA) species GU GA?? Estimated cost of structures (2003-5) Using review of van der Ree et al. (2007) $350k $1+mill $30k $5k $3mill

11 Specialised Structures for Arboreal Mammals - Ropes vs Poles Ropes Source: Bax 2006 Source: Goosem, Weston, Bushnell 2005

12 Poles Poles 1. One species only so far. 2. Several glider species or their populations listed as threatened. 3. Further field trials needed.

13 Specialised Structures for Arboreal Mammals Ropes & Poles Installations indicate the potential of these structures. Field experiments now required to investigate effectiveness. Relevance to Other Linear Barriers Size of canopy gaps & gliding ability important Bomaderry Ck, Nowra, NSW south coast.

14 Conclusions 1. Some arboreal species require specific structures. 2. Recognise the value of behavioural trials. 3. Further monitoring required. 4. Further research required.