|Why are monarch butterflies endangered of dying?
I heard from a newspaper that they are doing
studies on them.
|Question Date: 1999-02-25|
Thank you for your question. For general
information about monarch butterfly studies, you
can contact the following web
Now let me address your question, "Why are
monarch butterflies endangered of dying?"
Actually, some disagreement exists on this
point. First of all, you must remember that
monarch butterflies are insects. That means that
they can reproduce very fast when they have
adequate food plants for the caterpillars.
Personally, I cannot believe that the species will
perish, although we might see reduced numbers of
those butterflies if we are not careful about
Monarchs face three major
problems, as follows:
caterpillars feed only on milkweed plants.
However, those plants usually do best on farmland
and along roadsides. Farmers and highway
caretakers regularly mow or spray those plants
with herbicides. Those actions result in fewer
2) A microscopic parasite
exists on these butterflies and apparently causes
deaths in caterpillars. The adult butterflies
unwittingly transmit this parasite as they fly
from plant to plant while laying eggs. We have a
problem here. If we have a great many monarchs,
the disease can spread faster.
cannot survive really cold weather in any stage of
their life cycle. Thus, we consider them a
tropical or sub-tropical butterfly. During the
winter a great many of them overwinter in
particular aggregation sites in southern Mexico
and California. Some butterfly experts believe
that severe alteration of those overwintering
sites will destroy their migratory behavior. I
take a less extreme view. I don't believe we
enough about Nature to know whether that
is the case.
thank you for your interest in monarch
butterflies. We need more people like
Monarch Butterflies require milkweed plants when
they are in their caterpillar stage of life.With
the development of California, much of these areas
were cut down and made into homes, shopping
centers and parking lots. You see, with the
reduction of this one plant, you basically lower
the potential for reproduction of the butterfly.
Your question is not really a question
about biology--it's a question about people and
economics. Why do we, as people, feel the need to
have big yards for our houses, with
to shop in and big roads to drive our big cars
on--I think if you look more at the sociological
aspect of how people want a certain standard of
living and couple that with why some people feel
it is ok to develop land to the point that half
the business and half the homes are unoccupied,
then you might see that your question was more
about people and economics and not really about a
very pretty butterfly.
If you want to help
the butterfly--plant milkweed--it's not a pretty
plant, but it is necessary for the butterfly.
In a way, you have just answered your own
question. People aren't sure of why the
butterflies are dying so they do studies to find
out. There are maybe three general theories though
that apply to many endangered species. First,
their habitat is being destroyed so that there
isn't enough food, places to breed, or just live.
Habitat destruction can be many things; people
cutting down trees, cows eating vegetation or
trampling the habitat. Second, people or their
pets or animals are causing more of the
butterflies to die. This could be many things
also like a nearby road where butterflies get hit
by cars as they fly across. Third is that
invasive species are coming into the butterflies
habitat and taking over. This could be other
butterflies or predators like lizards that may be
especially good at catching the butterflies. The
cause could also be any combination of these. Can
you think of any other reasons?
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