Swift parrot numbers underestimated
NEW RESEARCH HAS FLAGGED up serious problems in estimates of endangered swift parrot numbers.
AGS-sponsored PhD student Dejan Stojanovic, at the Australian National University, Canberra, has found that many ground surveys with binoculars – which are completed prior to land clearing and affect conservation decisions – have underestimated or overestimated nesting sites of swift parrots (Lathamus discolor).
“These surveys are prone to huge errors. When you climb the tree you realise that of those 20 you spotted from the ground, five are stains in the bark, three are flooded and the rest are occupied by other animals,” he says. These errors are likely to contribute to poor conservation decisions for cavity-dependent species.
Work by Dejan and his coworkers has shown that the best way to find and count swift parrot nests is by actually climbing trees.
“Given the importance of tree cavities to wildlife, reducing errors in counts is necessary to improving conservation of forests and the animals they support” he says.
The south-eastern forests inhabited by swift parrots are threatened by the loss of cavity-bearing trees to forestry. This, coupled with the parrot’s habitat requirements, competition for nesting sites and high predation rates, has resulted in drastic population declines.
“Swift parrots are dealing with not only the rarity of the resource they need to survive, but are also competing with eight or nine other species that use hollows.” Dejan says.