IS THE UNUSUAL SUMMER AFFECTING WILDLIFE?
August 4, 2013
anything can be considered a driving force in ecology, it is the weather.
The following questions are representative of several I've received
in the last month.
Much of the southeastern United States has had more rainfall this summer
than normal, and weather reports for the Southwest, Midwest and Northeast
blab on about how hot it is or how much flooding there is. Considering
that a year ago we were talking about the extended drought everywhere,
what exactly is "normal"?
record-breaking spring and summer rainfall in many parts of the South
had any negative impacts on wildlife - either plants, animals or both?
Are the reports of greater numbers of snakes, alligators and mosquitoes
"Everybody talks about the weather but nobody does anything about
it." That's as true now as it was at the turn of the 20th century
when Charles Dudley Warner (or possibly Mark Twain) first said it. Weather
in most parts of the world is notorious for being unpredictable, and
people (including weather forecasters) are going to talk about what
they consider unusual.
maybe Warner) also said, "Climate is what we expect; weather is
what we get."
weather for a region or a season changes slightly each year. Actually,
having weather that was the same as last year is unusual. The average
temperatures, rainfall, wind speeds, etc. all vary from year to year.
This natural phenomenon of fluctuating annual weather patterns is one
reason climate change models are so difficult for some people to comprehend.
wildlife can adjust and adapt to whatever natural weather conditions
occur. Extended periods of rain, drought, cold or heat, which vary independent
of each other from year to year, are quite natural. No matter what the
prevailing weather is over several weeks or months, even from one year
to the next, some species will be winners and some will be losers. That
has been the natural pattern of species survival for millions of years.
The species that are here today had ancestors that successfully weathered
the variability and extremes in temperature and rainfall of the region
they lived in. That's one of the wonders of evolution.
the Southeast began experiencing an overabundance of rain starting in
early summer, but such weather is in no way unprecedented. Therefore,
although a few individual organisms may perish, virtually all species
of plants and animals - native, invasive or exotic - will persist. A
species may be extirpated locally or even over a wide region due to
extreme weather. But except in the very rarest of situations, the species
itself will continue to exist somewhere. The problems created by various
man-made environmental impacts are much greater and have a far more
lasting effect than those caused by any natural regional weather conditions.
become more apparent when unseasonably cloudy, rainy and cooler weather
occurs during a southern summer. For example, summer breeding frogs
might well be more active during such conditions, which can lead to
greater activity by animals that eat frogs and tadpoles. Snakes in particular
are more likely to be seen on quests for food. Meanwhile, mosquitoes
become more abundant during rainy periods in summer. The upside is that
insect-eating bats and dragonflies, as well as fish that eat the aquatic
larvae, will prosper because of an increased food supply.
of certain grasses and shrubs can also be stimulated by wetter conditions,
which in turn might lead to an increase in herbivores such as deer or
rabbits. Or various rodents such as rats and mice may become more obvious
in areas where they might not usually be seen. Again, more food for
certain snakes. And alligators, in areas where they occur naturally,
are more likely to be encountered because they tend to move overland
during humid weather.
fluctuations in weather are, well, natural. And barring human-caused
environmental complications, native species will adjust to such variations,
just as their ancestors did before them.
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