Direct and indirect evidence of black cockatoos roosting within trees was with the
subject site was noted if observed (e.g. branch clippings, droppings or moulted
No seasonal sampling has been carried out as part of this fauna assessment. The
conclusions presented are based upon field data and the environmental monitoring
and/or testing carried out over a limited period of time and are therefore merely
indicative of the environmental condition of the site at the time of the field
assessments. It should also be recognised that site conditions can change with
During the black cockatoo habitat survey trees with hollows were searched for. It
has limitations. Generally the full characteristics of any hollow seen are not fully
evident (e.g. internal dimensions). It is also difficult to locate all hollows within all
trees as some are not observable from ground level.
The location of observations was recorded using a handheld GPS. The accuracy of
the GPS cannot be guaranteed above a level of about 5 to 10 metres, though it
should be noted that in some circumstance the accuracy can increase or decrease
beyond this range.
Vegetation units within the subject site are shown in Figure 4 along with the location
of habitat photo points. It should be noted that the boundaries between the various
units shown is in some cases gradational and therefore their depiction is somewhat
subjective. The plan has generally followed the units identified by Coffey (2007),
though given that a detailed botanical assessment has not been carried out to
determine the full characteristics of the various broad units seen some have been
combined (e.g. all banksia woodland units). Some units have also been split and/or
their extent changed based on observations made during the field survey carried out
in May 2016.
It was also noted during the most recent assessment that some units previously
identified as being re-growth from a clearing event appeared to have changed
structure to a certain extent as evidenced by the presence of banksia species not
previously listed by Coffey in their report (Coffey 2007). This was particularly
evident in unit “AcBmBaTS” where banksia was not recorded by Coffey during their
previous survey work.
Table 2 below lists the flora species recorded by Coffey (2007) within sections of the
subject site along with their known or potential cockatoo foraging status (plus one
new species not previously recorded i.e. Eucalyptus marginata). It should be noted
that only five of Coffey’s 13 flora survey quadrats were located within the proposed
Table 2: Identified Flora Species within the Subject Site and Black Cockatoo
Note – some species were tabled in the complete flora list by Coffey (2007) but were not listed in quadrat
data and therefore their recorded location (i.e. in or out of offset area) is not known.
Fifteen plant species out of the total of 156 listed are documented as known food
sources for Carnaby’s black cockatoos based on available literature. Eleven of
these have been recorded in parts of the proposed offset area and 10 within the
balance of the site (includes two introduces species). Another nine species of plant
recorded within the offset area may possibly be foraged upon but this is based on
other members of their genus being documented as a known food source. Eight
potential foraging species have been recorded in the balance of the subject site.
The estimated foraging value of the various sections of the proposed offset area and
works footprint are shown in Figure 5. Habitat photographs taken at each photo
point where foraging scores was primarily assessed are held in Appendix A.
As indicated in Figure 5, the proposed offset area has an estimated foraging value
of between 3 and 4 with most areas being rated as 4, primarily as a consequence of
the dominance of banksia woodland over much of the area. Most of the areas rated
as 3 are in the relatively early stages of regrowth after an historical clearing event or
from 0 (cleared areas) to 4. Areas with the higher ratings (3 and 4) are again
characterised by the presence of banksia which is generally absent from areas rated
as having a lower foraging value.
A breakdown of the extent of each assigned foraging rating within the works
footprint and the proposed offset area are shown in Table 3 below.
0 to 1
0 to 1
Evidence of Carnaby’s black cockatoos foraging was observed during the field
survey in the form of chewed banksia cones at numerous locations. Example
images are provided below.