Thursday, August 7, 2008

Research in Duluth, MN

Recently the changes in the monarch population in Duluth, MN were studied. The research, entitled "The Rise and Fall of Danaus plexippus in Duluth, MN", was conducted from 2000-2005. The researchers proposed the following hypotheses (taken directly from the link below):
  • H1:The ratio of monarchs to milkweed will
    decrease year to year.
  • H2: Monarch eggs will always be in more
    abundance than the larvae.
  • H3: In six years the overall numbers of
    monarchs have decreased.
  • Null: The ratio of monarchs to milkweed will not
    change from year to year.

The conclusions varied from the original hypotheses (again, taken directly from the link below):
  • Every other year, the ratio of monarchs to
    milkweed increased or decreased; H1 was
    not supported.
  • H2 was correct: eggs were always more
    abundant than larvae.
  • In six years of monitoring, overall monarch
    numbers declined, supporting H3.
  • Ratios of monarchs to milkweed change
    annually, therefore rejecting the null
    hypothesis.

This chart can be found at:
http://www.monarchlab.org/research/strom1poster.pdf
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