SURVEY METHODOLOGY

Fauna was surveyed between 29 September and 20 October 1994. Survey effort is summarised below and trapping locations are indicated on Figure 1.
Survey method Survey effort
Active searching (direct evidence) 4 search-hours
Active searching (indirect evidence) 8 predator scats analysed
3 herbivore scats analysed
1 owl pellet analysed
2 skeletal remains analysed
1 hair sample analysed
Elliott trapping 50 trap-nights
Hair-tubing 1200 tube-nights
Spotlighting 2.25 spotlight hours

Active Searching

Active searching was conducted for a total of 4 search-hours. Ground-level habitats were
searched: in the base of grass tussocks, beneath exfoliating tree bark, and beneath hard litter (e.g. fallen timber, dumped rubbish, weed mat). Both indirect and direct evidence of fauna was recorded.

Direct Evidence

Direct evidence of fauna species includes actual sightings or identification of the species by distinct vocalisations or calls (e.g. birds, frogs and some nocturnal mammals).

Indirect Evidence

Indirect evidence of fauna species include identifiable body remains (e.g. bones, skin, fur), scats (droppings), diggings or burrows, and hair or body remains identified from predator seats. Scat samples and hair samples were analysed by Barbara Triggs (c/o "Dead Finish' Genoa, Victoria).

Mammal Trapping and Identification

Elliott -Trapping

Mammals were surveyed using Elliott traps (325 x 85 x 95 mm) baited with a mixture of rolled oats, honey and peanut butter. Traps were set in pairs at intervals of 10 m along two transects consisting of between 20-30 traps for a total of 50 trap-nights. One 'trap-night' is equivalent to one trap left open for one night.

Hair-tubing

Mammals were surveyed using hair tubes (large square section hair-tubes of dimension 100 x 100 mm and small circular section hair-tubes 35 mm in diameter) baited with a mixture of rolled oats, honey and peanut butter. Hair-tubes were set in a single transect around the perimeter of the island consisting of between 40 small tubes and 20 large tubes. Tubes were set at intervals of 10 m, either as a mixed pair of one large and one small tube or as a single small tube, for a total of 1200 tube-nights. One 'tube-night' is equivalent to one hair-tube set in place for one night.

Hair collected from hair-tubes was analysed by Barbara Triggs (c/- 'Dead Finish', Genoa).
Species were identified from hair structure and morphology. In some cases, when only a few hairs or damaged hairs were collected, definitive identification to species level was not possible.

Spotlighting

Mammals were surveyed by spotlight for a total of 2.25 spotlight-hours. Spotlighting was conducted on foot throughout. The river's edge was surveyed by spotlight from a canoe for the full perimeter of the island.

Bird Census

Bird species were incidentally recorded during all field survey activities.

Records From Other Sources

Fauna records from the local area were obtained from the Department of Conservation and Natural Resources. Atlas of Victorian Wildlife (area boundaries: N 37° 50', S 37° 51', E 145° 00', W 145° 01'). This list supercedes the list of species presented in DCE (1991).

Limitations

The present survey was carried out over a short time-frame restricted to a single season. Additional species may be recorded in the study area if further survey work was undertaken over longer periods or in different seasons.


Habitat Assessment

A habitat type is actually formed by floristic and structural features of the Vegetation which provide a set of resources to support a community of fauna species. In general, habitat types correspond to vegetation communities however habitats may be defined by other physical attributes of the landscape. Many fauna species move between habitats or utilise more than one habitat.

Habitat quality is assessed according to the following descriptive criteria.

high - ground flora containing a high number of indigenous species; vegetation community structure, ground log and/or litter layer intact and undisturbed,- a high level of breeding, nesting, feeding and roosting resources available; a high richness and diversify of native fauna species

moderate - groundflora containing a moderate number of indigenous species; vegetation community structure, ground log and/or litter layer moderately intact and undisturbed, a moderate level of breeding, nesting, feeding and roosting resources available,- a moderate richness and diversity, of native fauna species

low - groundflora containing a low number of indigenous species, vegetation community structure, ground log 'and/or litter layer disturbed and modified; a low level of breeding, nesting, feeding and roosting resources available, a low richness and diversity of native fauna species

A habitat can be attributed high value for additional reasons including:

Defining Significant Species

The significance of fauna species was assessed at national, state, regional and local levels. The national and state ratings for significant species were taken from published lists which are recognised by the scientific community as well as by Government bodies. Because new biological information on some species is now available and lists are only published periodically, it is sometimes necessary to update significance ratings. The significance of invertebrate fauna was not assessed.

Within a given geographic context (Australia, Victoria, region, locality) a species has a particular conservation status (extinct, endangered, vulnerable, rare, indeterminate, and insufficiently known)2. These conservation status definitions are based on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Animals (IUCN 1988).

National

Species of national conservation significance are considered to be endangered vulnerable or rare either internationally or within Australia. Ratings are determined from a composite of international and Australian listings: the International Union for the Conservation of Nature (IUCN) Red List of Threatened Animals (IUCN 1988), the unpublished list of endangered species produced by the Council for Nature Conservation Ministers (ANZF-CC 1991), species listed under the (Commonwealth) Endangered Species Protection (ESP) Act.

State

Species of state conservation significance are those which are endangered vulnerable or rare within Victoria. Ratings are determined from a composite of lists: the 'List of Threatened Fauna in Victoria 1993' (Baker-Gabb, 1993) and the list of species protected under the Flora and Fauna Guarantee (FFG) Act.

Regional

For the present study, species of regional conservation significance are those which are endangered, vulnerable or rare within the Greater Melbourne Area as defined by Schulz and Webster (1991). This is an extensive area including the Mornington Peninsula in the southeast, Geelong and the Bellarine Peninsula in the southwest, Bacchus Marsh and Wallan to the northwest and north and the upper Yarra region to the northeast.

There are no definitive published lists for species of regional conservation significance within the Melbourne region. Regional status for fauna was assessed by referring to relevant government reports, by consulting relevant local studies (e.g. Larwill et al. 1991), by consulting experts familiar with the area, referring to the literature, and by drawing upon the previous field experience of the Consultants.
2 Historically, species which are 'endangered', 'vulnerable', 'rare', 'indeterminate' or 'insufficiently known' as defined by IUCN (1988) have been described by the general term 'threatened'.