Fauna: |
In order to be able to obtain a reliable estimate of the number of little corellas on the Fleurieu Peninsula it is critical to
conduct synchronised counts at each of the sites where little corellas are known to roost over night. These counts need to be
conducted at dawn to enable the observer to count the birds as they fly out from their roost site. Synchronised counts will not
only ensure that birds are not being double counted, or missed all together, it will also provide some insight into the degree to
which birds move between flocks. If the number of birds in a flock decrease at one site and increase at another site the same
day, then it can be assumed that birds have moved between these two roosting sites. This is only a very rough guide to the
amount of mixing occurring, and will not provide any information about individual bird movement between flocks but it will
provide a useful insight for managers as to whether this occurs or not, and whether there is any seasonal pattern to this
mixing. There will always be some error associated with counts of large numbers of birds in flight. Therefore to minimise this
error and increase the robustness of the estimates, individual observers will be assigned to a site, and the same observer will
conduct all counts at that site (where possible). A meeting will be held after the first couple of weeks of counts to discuss the
methods being used by all observers and to ensure consistency across the sites. The aim of this project is to determine an
estimate of the little corella population across the Fleurieu Peninsula. However it may be impossible to decipher between
little corellas and long billed corellas and sulphur crested cockatoos among large flocks of flying birds. Observers will be asked to record what proportion of the flock they believe is each of these three species so estimates can be adjusted if required. While misidentification of birds may lead to an over estimation of the population size of little corellas on the Fleurieu
Peninsula, it is envisaged that this will not be a major limitation as little corellas will make up the majority of these flocks.
Moreover, where flocks comprise of these other species, the general community are unlikely to recognise the difference
between the species, and thus all contribute to the real or perceived impact from these birds. |