At 23:00 27/11/98 +1100, Anthea Fleming wrote:
>Could it be that the gecko tails stay where they are - even if they
>thrash and writhe about - while the geckos themselves leave hastily?
>Best I can suggest! I believe some geckos give off ?defensive fluids
>from glands on back, which might be relevant, if stinging or
>evil-flavoured. What species of gecko by the way?
I like anthea's explanation about the tail being stationary while the gecko
scutes off. After all, this is the whole point of the tail falling off
(autotomisation) and flopping around, to fool/appease predators while the
lizard hides, slowly sneaks off or flees. Perhaps the tail is also tastier
or otherwise more appealing than the body to black butcherbirds.
There are two "house geckos" in Cairns, the native Gehyra dubia and the
feral Hemidactylus frenata. Gehyra is strictly nocturnal whereas
Hemidactylus frequently forages by day.
Hemydactylus is perfectly palatable: chooks, jungle perch and barramundi
eat them greedily. I have seen cats eating Gehyra dubia so I guess that
they are palatable as well.
defensive skin secretions of Australian geckos are limited to the genus
Strophurus (or Diplodactylus). They work mostly by being sticky, irritating
to eyes and bad tasting and smelling rather than toxic. They have been fed
to chicks and rats in experiments. Anyway, they are mostly secreteted from
the tail itself.
reference:
Glasby & Beesly (eds) 1993. Fauna of Australia 2A: Amphibia and Reptilia
David James
PO BOX 5225
Townsville Mail Centre 4810
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