On Mon, 23 Oct 2000, Penny Drake-Brockman wrote:
> I bought a pair from Wires at least 5 years ago and have had them on my 4WD
> ever since but have never known whether or not they work as I drive very
> slowly at dusk when in a 'roo/wombat area. However I met someone out at
> Wanaaring (NW NSW) who lives at Bundeena (south of Sydney on the edge of
> the Royal National Park) who swore about the effectiveness of his as he
> drives regularly from Bundeen through the park to Sydney, and as anyone who
> visits the park knows, there are huge quantities of feral deer there and he
> swears it works with them, although maybe deer are a bit more road wise
> than wombats and 'roos.
I was curious to know if kangaroos could hear ultrasound such as these
whistles supposedly produce. A quick search found a review article on
marsupial hearing [1] but its seems to indicate that the hearing ranges
of only two Australian marsupials has been described.
The Northern Quoll has a hearing range which is similar to humans and
which is generally less sensitive. So if you can't hear these whistles
the Quolls probably won't either.
Brush-tailed Possums hearing is most sensitive at 18khz. This is
surprisingly high - near the limit for younger humans. Brush-tailed
Possum hear well until about 30khz and then there hearing rolls off
sharply. So a whistle in the range 20-30 khz might be audible to
Brush-tailed Possums at some distance without being audible to most
humans.
Andrew Taylor
[1] The auditory neurobiology of marsupials: a review, L. Aitken,
Hearing Research, 82, p257-266, 1995
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