- Monarch butterflies migrate from the U.S. and
Canada to Mexico every winter. Over the past
10 years, there has been a drastic decrease in
the number of monarch butterflies. Scientists
have estimated that the population may have
decreased from about 1 billion to 35 million.
Which action would not be considered a
reason for the decline in monarch butterfly
populations?
(1) illegal deforestation
(2) extreme temperature changes
(3) decreasing food supplies
(4) habitat preservation