What factors are involved with the hummingbird and the monarch's choices of flowers?
Here are some clues to think about:

Hummingbird Bodies/ Behaviors

Monarch Bodies/ Behaviors
  • Long slender bills (15-20 mm length)
  • Need lots of surgar for energy
  • No sense of smell
  • Able to hover
  • Able to see well in the red (long wavelength) end of the color spectrum
  • Relatively long, narrow probiscis (11-12 mm length)
  • Need lots of sugar for energy
  • Good sense of snell
  • Must land in order to feed
  • See well in most of the color spectrum, except in the red end.


What Scientists Think

Why hummingbirds prefer red ( 2 theories):

  1. During migration red blossoms contrast very well with a green environment. Hummers have a good sense of sight.
  2. Insects, such as monarchs, see poorly at the red end of the spectrum. They're more likely to pass up red blossoms. This leaves more nectar for the hummers (and they learn this quickly).
The monarch's ultraviolet powers:
Many flowers have light patterns in the ultraviolet end of the spectrum. Monarchs and other insects can see these, but humans and birds cannot.
looks yellow
How an evening primrose looks to a human or bird.
looks blue
How an evening primrose looks to a monarch.

If you were an insect, how could you tell where the nectar is hidden?

Photos: Windows to the Universe
Add what you learned about flowers to your Journal answer.