Q: (Initially posted June 7, 2004) FROM STUDENT MEMBER ALEXIS K. IN VA
Cicadas are separated into Brood types. Broods emerge in either thirteen
years or seventeen years. The brood currently making everyone scream, called
Brood X, is gushy large and makes a frightening noise when they are
disturbed. Beyond that they are stunning with large, saturated red
marble-round eyes and wings intricate enough to make tinkerbell jealous....
My question...I do have one!...is what happens to the bird and
other creature populations that feast on these winged McNuggets? Wouldn't it
nourish other creatures enough to raise their population for at least a
year? Wouldn't that change the food chain in all directions? Who studies
this dynamic? Don't you think that a career being a cicada specialist sounds
smart - you would have work every thirteen or seventeen years and can sit
around the rest of the time. Cool, huh?

June 10, 2004
A: FROM MENTOR JOAN LUSK IN RI
Great question! (Risky career path, though - sitting around for seventeen years you might starve to death with no income!)

The glut of cicadas must set off a typical predator-prey cycle. Population biologists and ecologists study these cycles, and mathematicians model them. When populations of prey (species that are food for predators, as cicadas are for birds) increase, the abundant food caused predator populations to increase. Then, when the prey are no longer abundant - they may have been eaten up or, in the case of cicadas, gone into their underground life cycle - the populations of predators decline. There's a typical graph of this, with explanation, at
http://www.globalchange.umich.edu/globalchange1/current/lectures/predation/predation.html. You'll also find it described in many biology books, if they deal with populations as well as individual organisms. Cycles like this take place even without big changes in the overall environment. If the climate is really changing, there will be even more changes to study, and biologists will have to figure out whether a sudden change in a population is part of a cycle or a more permanent change, a shift to a new environmental equilibrium.

So in the 13 or 17 years between cicadas, you'd find some other species to study (and make a living from). You, as a human being, can shift to other intellectual "prey" and not have to starve. One of the wonderful aspects of biology is that you can study it as a mathematician, modeling stuff like these cycles, or as a chemist, studying the molecules and reactions of life, or as a visual artist doing anatomy and microscopy, or an animal (or plant) lover relating to individual animals (or plants), or as someone who can make the grand synthesis from molecules to organisms to ecosystems.