Appendix D Terrestrial and Aquatic Biodiversity - Environment ...

SZ247: Bat survey from the Western Desert Resources Towns River project area, NT
4.0 RESULTS
4.1 Expected species
A maximum total of 22 species was expected from the Roper River – Limmen – Borroloola
area based on the distribution records compiled in Milne and Pavey (2011), of which three
species are listed in an elevated or data deficient conservation category (S. saccolaimus;
Macroderma gigas; Rhinonicteris aurantia; Table 1). Within any one locality, the species
assemblage is likely to be smaller than this regional total, on the basis of the habitats present.
In addition to these, there are two species that might also occur in this area, but are currently
only known from records adjacent to the region (Northern leaf-nosed bat Hipposideros
stenotis; Pallid long-eared bat Nyctophilus daedalus). Both of these species are known from
relatively few records and might be distributed sparsely across their range (Milne and Pavey
2011).
4.2 Acoustic detection
A total of 12 AnaBat sessions and 10 D500x sessions were made in the MLA – Towns River
project area (Table 2; Figures 1 – 4), in addition to a further 33 recording nights over several
surveys in other parts of the project area (Table 3). All represent a full night of passive
stationary recording.
At least six species of echolocating bat were identified from the acoustic recordings made in
the MLA – Towns River project area, with the possibility of several others than cannot be
distinguished reliably from their echolocation call characteristics. In addition, at least one
species of flying-fox Pteropus sp. was observed at three sites, however identification to
species could not be made. At least nine species were identified as being present in the
other parts of the project area, with the possibility of others that could not be distinguished
based on echolocation call characteristics (Table 3).
Details supporting the identifications are provided, as recommended by the Australasian Bat
Society (ABS 2006). A summary of pulse parameters is provided in Table 4, and
representative call sequences are illustrated in Figure 4. Further data is available should
verification be required.
4.3 Trapping
A total of 20 individuals from five species was captured at four trapping sites, most being from
mist nets spread over water bodies (Table 5). The majority of captures came from a broad
river habitat in the south-east of the MLA – Towns River project area. Long-eared bats
(Nyctophilus geoffroyi) were captured in mist nets (M01, M02) and a harp trap (H1) in riparian
vegetation away from the main river channel. The understorey vegetation at site H1 was
relatively dense. One individual of Saccolaimus was captured as it flew low over a long pool
in the Towns River. It was identified to species (S. flaviventris) on the basis of a relatively
broad inter-canine width (6.05), according to the scheme in Milne et al. (2009), plus the
absence of a palpable lambdoidal crest (KN Armstrong unpubl). The specimen has been
lodged in the South Australian Museum (temporary accession number BS5949 temporary
accession number 12.052).
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