Fit for Survival
Who's Fit to Survive?
If a habitat
or ecosystem changes dramatically — through drought, flood, or human
activity, for instance — individuals can't necessarily quickly adapt
to new conditions. For instance, people destroy habitats by clearing trees,
breaking them up with buildings, or polluting them. Some animals are able
to move to new locations or survive in the new conditions, but other species
are put at risk or eliminated altogether.
The more intelligent a species is, the faster an individual can
make behavioral changes that help it (and its offspring) survive.
Our hefty human brains, for instance, can respond quickly by creating
technology to solve problems that environmental changes bring. Consider
space suits, heating and cooling technology, and sun screen. But
do we always use our brains to anticipate or respond to
problems? Ponder that one!
called generalists if they are adaptable to many kinds
of habitats and food sources. If, on the other hand, they have very specific
habitat and food requirements, they are known as specialists.
Why do you think the endangered species list includes many specialists
and hardly any generalists? This latter group is at greater risk
if their limited food source or habitat disappears. (For example, monarchs
have very specific habitat needs in their wintering grounds.)
As you explore
Journey North species, think about where each might fit into this scheme,
and what the implications might be.