Sociobiology, Evolutionary Psychology, and Behavioral Ecology

By: Bird, Smith, & Bird

Presentation by Ashlee D

Foragers (human and not) will choose foods that offer the maximal energy return for the minimal energy investment. (415)

-The article intends to explain instances in which OFT don’t work and provide an ulterior explanation.

Optimal Foraging Theory (OFT)

The Question:

Why do some Meriam hunters choose to go after prey that is low in nutritional return and is also hard to get?

“Serves as an honest signal” (416)

Proposes that communication between individuals with conflicting interests can be evolutionarily stable if the signal honestly advertises an underlying quality of interest to observers.

Costly Signaling Theory (CST)

Criteria for hunts to meet CST

Differentially costly or beneficial in ways that are

Honestly linked to signaler quality

Designed to effectively broadcast the signal to the intended audience (i.e: potential allies, mates, and competitors)

Spear-fishing

Men forgo shellfish collecting to spear-fish

Though shellfish collecting would maximize energy in, while minimizing energy out.

Searching for fish (to spear) takes a lot of time and energy and has little energy return.

Why? Spear-fishing continuedThey are maximizing other nutrients

o BUT protein and fat is higher in shellfish

Other benefits (unrelated to consumption) such as good trade itemo But, shellfish produces larger harvest and is more likely to

be shared

Provides greater consumption benefits long runo kfsdjm

Turtles!

Collecting HuntingVS

Turtle hunting may involve:“High opportunity costs in the form of

passing over opportunities to acquire other resources with higher rate of return.Low consumption return rates because the hunters distribute to non-huntersHigh energetic, monetary, or time investment costs of preparing for and conducting the hunt that reduce energetic return rates below that of more easily acquired resources” (423)

The (honest) signals given:Spear-fishing

o Hand-eye coordinationo Stealtho Patience

Turtle huntingo Strength, stamina, risk takingo Cognitive skillso Leadership o Generosity

Some problems:

Where are the interviews with the people?Phenotypic traitsIdeas/explanations that couldn’t be tested or were not tested/completed at time of publication

Food for thought