DOES THE WILDLIFE SOCIETY DO FOR US?
May 6, 2012
you look for triclopyr, sethoxydim, and imazapyr? Should you be concerned
about the fate of the addax, dama, and scimitar-horned oryx? And what
do these odd words have to do with ecology?
to the last question is that all were mentioned in recent news updates
from the Wildlife Society, whose mission is "to represent and serve
the professional community of [those] who work actively to study, manage,
and conserve wildlife and its habitats worldwide."
triclopyr, sethoxydim, and imazapyr, they are neither former states
of the Soviet Union nor invasive insects from North Korea. They are
compounds found in herbicides that you might find in your garden shed
or garage. You are not apt, however, to find an addax, dama, or scimitar-horned
oryx in your yard, as they are endangered African antelopes. Both the
herbicides and the antelopes present the kind of environmental dilemmas
that are likely to become more common in the future.
do not mix well with insects. An article in the international journal
Environmental Pollution reported on the negative effects of herbicides
on a butterfly known as Behr's metalmark. The relatively common butterfly
was chosen for the study because Lange's metalmark butterfly, a close
relative, is endangered and near extinction. One reason Lange's metalmark
is on the last of its six legs is that it occurs in a small habitat
in California where its primary food source, naked stem buckwheat, is
being overcome by invasive exotic plants. The invasive plants are controlled
with various herbicides.
on the response of Behr's metalmark to the three herbicides revealed
that toxic effects reduced the number of pupa that emerged as adults.
These results are presumably indicative of how the herbicides affect
Lange's. The reasons for the effects vary among the herbicides, but
the conclusion is the same--herbicides can have potentially serious
detrimental effects on butterflies. What irony. Herbicides that reduce
the viability of the metalmark are necessary to keep invasive plants
from eliminating the buckwheat that is essential for the butterfly.
A true California conservation conundrum that might best be addressed
by letting nature decide the outcome without any more human input.
surrounding the antelopes stems in part from their being found in Texas.
Here's the situation. The IUCN classified the magnificent scimitar-horned
oryx extinct in the wild more than a decade ago. The addax antelope
and dama gazelle are critically endangered, thus approaching extinction,
in their native North Africa. The threat to the three antelopes might
appear to be ameliorated because populations of captive-bred oryx (11,000),
addax (5,000), and dama gazelles (800) flourish on Texas ranches. Could
they ultimately be transported to their native lands in Africa to replenish
the lost herds that were once abundant? Not likely. Threats from poaching
and habitat loss in Africa make reintroductions unlikely to succeed
without stringent regulations and fundamental changes in deep-seated
cultural and political attitudes across several countries.
the U.S. Fish and Wildlife Service had already listed the three antelopes
as endangered species. Two words ("wherever found") added
to the listing of each may have a major impact on the captive-bred animals
in Texas. Until this year, free-roaming antelopes on Texas ranches could
be legally killed in controlled, paid-for hunts. Not any longer. Animal
rights activists who want to protect individual animals from being hunted
and killed have worked to have the "wherever found" provision
antihunting actions justified? Some conservationists appreciate that
each antelope species has a relatively large population, even if they
are not on their home continent and are preserved for the purpose of
sport hunting. By removing the incentive for Texas ranchers to continue
increasing the world population size of the antelope species, will nature
now continue its trajectory toward extinction for all of them, with
no chance for recovery because none are left anywhere on Earth? Will
a victory for individual animal rights result in the loss of three entire
species? Another conundrum to reflect on.
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