Bite of the Bandy-Bandy,
and other tales from the world
of a herpetologist
There’s been a lot
of talk about unwanted visitors. I’m not talking about in-laws or college
students on an extended return from school. The visitors to which I refer have
gone under a suite of pejorative titles: tramp species, non-native species,
introduced species, and injurious wildlife. If you’ve been reading the
herpetological magazines this past year, you are aware that Hawaii is now
hip-deep in a campaign against such animals. There are few places that aren’t
concerned, to at least a small degree, about preserving the “natural” order of
local Nature. Noble efforts, in some cases, but a bit confusing in concept and
confused in practice.
We have all been
exposed to the stories about the invasion of Guam by brown tree snakes (Boiga
irregularis), voracious “tramps” that have decimated much of Guam’s native
bird populations. Considerable expertise and expense has been paid to eradicate
the snakes, to limited effect. The biological fall of Guam became a rallying
point for preservationist actions. How justified are such eradication stances?
Certainly we have
witnessed unwise (and this a charitable choice of words) introductions around
the world. Mongooses were brought to Caribbean islands that lacked venomous
snakes in order to eliminate perceived venomous snakes. They decimated
poultry and small native animals and contributed to increased diseases.
Australians imported rabbits to provide some “familiar” European animals. Crop
damage by rabbits is now almost legendary. As is the damage done by cane toads.
Poor Australia; even when it didn’t import the troublemaker, it helped increase
the threat’s population size. Unaware that cut-up sea stars (“starfish” to
some) will grow into new sea stars, Australian fishermen and (?) biologists captured
crown-of-thorns sea stars, hacking them to bits, and tossing the still viable
remains back onto the reef!
I thought
California led the pack in released wildlife paranoia until the Hawaiian issue
came along. Does anyone with herpetocultural experience believe that Jackson’s
chameleons are a threat to bird populations? Granted that an adult lizard might
take a fledgling, how rare is this event? My gray cells hurt when trying to
conceive of day geckos as “injurious.” Sadly, almost nothing of “native” lowland
Hawaii is still in place. Humans long ago annihilated the few true natives,
replacing them with agricultural lands, ornamental plant (non-native) farms and
tourist facilities. Certainly Hawaii should conserve its remaining native
wildlife, but few native species dwell near cane fields and swimming pools.
The preservation of
natural areas, if intelligently conceived and enacted, should be given
highest priorities. What is so often overlooked is the reality of the number
and degree of invasiveness of so many “foreign” species. Herpetoculturists may
cringe when told Jackson’s chameleons will devastate Hawaiian birds, or that
alligators may proliferate and become a threat in San Francisco, but does
anyone consider that the most destructive animals—barring the all too obvious
humans—are domestic cats, rats, and assorted plants? Goats were a big problem,
but they have been culled from islands ranging from Round Island to New
Zealand. Round Island, a tiny mound in the Indian Ocean, has had its goats
removed in a so-far successful effort to preserve the rare and endemic gecko,
skink, and boa species. Too late, alas, for one of the boas, now considered
extinct. Cats are pets, and few people really consider how much damage they do
to small animals, native or not. There are many more critical battles to wage
than those against questionably influential species.
In my “natural”
California neighbourhood, I am surrounded by eucalyptus trees (Australian
imports, brought over by some genius who incorrectly thought they would provide
a good source of lumber), and Mediterranean ice plants covering the fragile
sand dunes. Ice plants have broad, fine roots that effectively take all the
water in the soil, crowding out native plants and insects. Many streams are
filled with the large tadpoles of non-native eastern bullfrogs (imported as a
food commodity), which have steadily been eliminating the native frogs. English
sparrows are common here. Mediterranean fruit flies periodically threaten
(mostly non-native) crops. If I want to see a “native” coastal community, I
have to go to a State Preserve, where I must stay on the designated path.
Natives are now rare and often threatened.
We are told that
humans are the main movers of animals and plants, to the detriment of native
species. Geological facts dispute this assertion; how can humans compete with
events such as the ramming of North and South America to allow hitherto
unprecedented exchanges of species? Winds, rafts, and temporary bridges also
contribute to the colonization of islands and continents. To use Hawaii as an
example again, how else did the volcanic islands—never connected to or even
located near a continental mass—obtain its flora and fauna? Long before human
colonization, rafts, winds and sea birds brought seeds, insects, spiders, and a
few lizards. Humanity has merely accelerated the rate of species transport. As
a biological species, humans must be seen as a natural—albeit very rapid and
effective—factor altering the global biogeography.
Maybe it is time to
take a different view of “non-native” species. Looking at the paleontological
record, few species alive today were “native” to their present distributions in
times past. Biogeography is the study of distribution and dispersal of
species. The dispersal we see today is “natural,” unless we can truly see
humans as separate from everything else on Earth. Maybe the preservation of
diversity should be more focused on defensive actions in largely uninvaded
habitats rather than offensive actions against new colonizers.
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