6
1970 to 2012. “In other words,” the report authors write, “the
total number of wild animals with backbones has fallen by more
than half within one human lifetime.”
2
The report also states that
the number one cause of wildlife decline is habitat loss, especially
due to unsustainable agriculture practices and logging. Habitat
degradation is also playing a major role in the decline of wildlife
populations.
Humans Undoing the Damage They Cause
Habitat loss poses a serious threat to wildlife throughout the
world. But in the United States, the Endangered Species Act
(ESA) does a great deal to protect wildlife. This legislation has
been in effect since 1973, when the US Congress enacted the
ESA to strengthen existing federal protections for wildlife. Un-
der this law, for a species to be protected, it must be listed
as threatened, meaning likely to become endangered soon; or
endangered, which means on the brink of extinction now. The
three key elements of the ESA are preventing listed species from
being killed or harmed, protecting habi-
tat essential for those species’ survival,
and creating plans to restore healthy
populations of listed species.
Since the ESA has been in effect, it has
meant the difference between survival and
extinction for hundreds of America’s wild-
life species. One creature that was saved
from extinction is the bald eagle. The ma-
jestic birds were nearly wiped out by a va-
riety of human actions, including habitat
destruction and contamination of food sources by the deadly pes-
ticide DDT. When female eagles ate the poisoned food, it thinned
the shells of their eggs, making them break easily, thus, killing their
chicks. Although eagles had been under federal protection since
1967, the prolific use of DDT remained a deadly threat to them.
In 1972, the year before the ESA became law, DDT was banned.
Once the ESA went into effect, bald eagle habitats (nesting ar-
eas) were protected more than they had ever been before. Captive
WORDS IN
CONTEXT
vertebrates
Wildlife species (ma-
rine and land) that
have backbones.
