monarchs are there? What causes monarch numbers to change from year to
year? Many complex factors interact that ultimately determine a population's
size. To appreciate the scientists' challenge think the problem through
On the chart
below, list all the factors you can imagine that might cause high or low
numbers at each stage of the monarch's annual cycle.
with the breeding season. What factors might influence the number of
eggs laid? What might cause the eggs or larvae to die? The adults? What
might help greater numbers to survive?
- Next consider
the fall migration. (Review fall migration updates for ideas.) What
causes monarchs to die during fall migration? What challenges can you
- Then consider
mortality at the over-wintering sites. What are the causes of death
consider the spring migration. (Review spring migration updates for
ideas.) What causes monarchs to die during spring migration? What challenges
can you identify?
maintain this chart during your monarch study. How many ideas can you
add over time?
Season in Mexico
dynamics" is the study of changes in the number and
composition of individuals in a population, and the factors that influence
Science Education Standards
Ask a question about objects, organisms, events. (K-4)
An organism's behavior patterns are related to the nature of that organism's
environment, including the kinds and number of other organisms present,
the availability of food and resources, and the physical characteristics
of the environment. When environment changes, some plants and animals
survive and reproduce, and others die or move to new locations. (K-4)
People have always had questions about their world. Science is one way
of answering questions and explaining the natural world. (K-4)