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Vol.
XXV, No. 5—September/October, 2000
Habitat
loss is recognized as the greatest threat to most plants and animals on
the list of threatened and endangered species. Many people are also aware
of other activities that directly harm listed species, such as killing
and over-exploitation for trade purposes. Unfortunately, these are not
the only dangers. With human assistance, species from one part of the
world are invading other regions that have no defense against them. These
invaders can be as large as a snake, as small as a bacterium, or as seemingly
harmless as a wildflower. Other threats, such as contaminants from industrial
and agricultural sources, are often unseen until they cause fish die-offs,
malformed frogs, or thin-shelled eggs. This edition of the Bulletin takes
a look at these lesser-known threats. |
