Aloha, Dr. Werner
I have to agree that if a gecko just dropped off the ceiling on its own,
it probably was sick. However, there are much more likely reasons for a
gecko to fall from the ceiling! ;)
We encounter geckos falling from the ceiling of our home & lanai, and
from our banana trees, with regularity and the reasons are not at all
unusual -- they are either distracted with fighting, mating, or being
chased by another gecko. It happens quite often and usually they just
lie stunned for a few minutes and are then able to run off, but some are
not so lucky and are injured. This is the first we've had that was
fatally injured from a known fall.
We have had them land on us, on our laps, computers, beds, and whatever
else happened to be under them. Most are day geckos, but quite a few
house geckos, and occasionally a mourning gecko (being chased) will fall.
I have a more personal view of the day gecko impact & the history of
geckos in Hawaii. My understanding is that the first geckos who arrived
either with or before the Polynesians included the mourning gecko
(Lepidodactylus lugubris), stump-toed gecko (Gehyra mutilata),
Indo-Pacific gecko and the tree gecko (Hemiphyllodactylus typus).
I agree that the concern with the house gecko was it would displace the
"native" populations, which it has done to a fair extent, with only the
mourning gecko remaining in urban areas and the others driven into less
developed areas. But the concern with later species has now mostly
turned to the impact on other elements of the ecosystem.
When the first day geckos were introduced, naturalists feared that both
the mourning gecko and the house geckos would be at a severe
disadvantage. And from experience, I can say that for several years it
became uncommon to see any brown geckos around our house or around town.
But both the house and mourning geckos have made something of a
comeback, and we now have quite a few representatives of both these
species.
And they mostly, but not totally, compete for the same insects. We have
observed that at least the Gold Dust Day Gecko is much lazier than the
house or mourning geckos and will not pursue its prey very far, which
tends to limit the insects that it eats. We have seen house geckos
tackle large cockroaches that barely fit down their throats, while a
gold dust will not even bother chasing one. But the day gecko is also
larger, which enables it to eat larger insects. They can bring down
large cane spiders and even hawk moths. They don't discriminate as to
whether the insects they eat are exotic or endemic, of course.
With the introduction of the larger day geckos, including the giant day
gecko (Phelsuma madagascariensis) which has established in Manoa, the
threat to native insects has increased. Additionally, the amount they
consume also reduces native birds' food supplies and interferes with
native plants pollination according to the DLNR (Department of Land &
Natural Resources).
Unfortunately, it's not a matter of a simple replacement of one similar
animal for another. And even if it were, as much as I like the day
geckos -- I prefer the native species. So my preference is to have the
original geckos, particularly the mourning gecko, which was the most
common species prior to the introduction of the house gecko. Likewise, I
would prefer the house gecko that has been around the last 60 or so
years & whose impact is now known, rather than the more recent
introductions whose final impact is yet to be determined. I love Hawaii
with all her uniqueness and I hope to keep her that way. ;)
Mahalo, Sherron
yehudah werner wrote:
Hello,
The recent messages re geckos requiring euthanasia and this being
problematic on Hawaiian islands, stimulate 3 comments.
1, A gecko that drops off the ceiling and/or lands other than on
its four feet is probably sick to begin with.
2, Even geckos don't live forever. What does everybody do with the
dead pets? They should be donated (with maximum info on their origin,
age etc.) to some public museum collection.
3, To my understanding, on Hawaii, the colonizing day geckos are
semi-banned not for their endangering the local insects (this is
already done by the local geckos) but because they displace the local
geckos. This of course means that they displace /Hemidactylus/
/frenatus/, who since arrival in the 1940s has been displacing
/Hemidactylus/ /garnotii/, who arrived much earlier. The moral
difference between the waves of invasion is that the early invasions
were unintentional (which is natural for commensal geckos), whereas
the latest is supected of having been intentional (artificial).
Hoping to have served, Yehudah
Yehudah L. Werner
Professor Emeritus of Zoology
Department of Evolution, Systematics and Ecology
The Hebrew University of Jerusalem
91904 Jerusalem, Israel
Tel. 972-2-6585874 (direct)
Fax 972-2-6584741 (departmental office)
e-mail [EMAIL PROTECTED]
Home tel./fax 972-2-5665576
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Gecko aka Sherron, Kailua Kona, Hawaii (on the Big Island of Hawaii)
Homepage: http://hale-pohaku.com/sherron - mailto:[EMAIL PROTECTED]
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