 | Periodical cicadas fill the summer air with their trilling mating songs. Cicadas spend most of their lives as wingless nymphs underground, feeding on tree roots. When they emerge, they molt into winged insects to mate, leaving behind ghostly shells. Some emerge from the ground every 13 years, others every 17. |  |
Both broods will reach maturation this year, creating an almost deafening cacophony of males buzzing to attract female mates.
This irregular emergence of thousands of cicadas all at once is a survival strategy called predator satiation. The birds and snakes that glut themselves on cicadas can’t eat all of them, ensuring that many will survive to breed the next generation.
This irregular emergence of thousands of cicadas all at once is a survival strategy called predator satiation. The birds and snakes that glut themselves on cicadas can’t eat all of them, ensuring that many will survive to breed the next generation.
 | Oak trees utilize a similar strategy called mast seeding. Every 2-5 years, the oak trees in a given region all produce a bumper crop of acorns, up to 10,000 per tree. This overwhelms the squirrels, chipmunks, deer, and other nut eaters, leaving extra acorns to grow into young oak trees. Oaks produce acorns every year, and some of these are buried and forgotten by squirrels, or missed entirely. But not every acorn germinates, and very few seedlings survive to become adult oak trees. By producing an overabundance of acorns at random intervals, the oak trees of a forest increase their odds of successful reproduction. |
Why not produce a bumper crop of acorns every year, or in the case of cicadas, emerge to mate more frequently? This actually would have a detrimental effect on species survival. It would encourage predators to expand their populations to take advantage of the abundant food source: hordes of squirrels and deer munching on acorns, mobs of birds and snakes devouring cicadas.
By utilizing a random (oak) pattern of overproduction or rare (cicada) pattern of overpopulation, predators can’t expand their numbers fast enough to consume all of the bounty, leaving plenty of individual acorns or cicadas to seed the next generation.
By utilizing a random (oak) pattern of overproduction or rare (cicada) pattern of overpopulation, predators can’t expand their numbers fast enough to consume all of the bounty, leaving plenty of individual acorns or cicadas to seed the next generation.
 | On the flip side, animals that eat a very specialized diet—for example koala bears, who eat only eucalyptus leaves—are more susceptible to die off if their specific food source declines due to habitat loss or climate change. However, generalists who eat a wide variety of foods—like racoons, coyotes, and humans—are able to adapt more easily to habitat changes. As humans continue to destroy natural habitats through overdevelopment and climate change, generalists will become more dominant and specialists like the adorable koala will dissappear. |
Take-aways:
- opportunistic gluttony is natural, so go ahead and eat that whole pizza (but only occasionally)
- omnivores with varied tastes have the best odds of surviving the climate crisis
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