1. The Australian Gidjingali foragers are skilled shellfishcollectors. Let’s say a woman alone can collect 3 kgs/hr ofshellfish. If she brings her baby with her to forage, she’d be ableto collect only 2 kgs/hr of shellfish. If she stays in camp, thereare some nearby tiny fish she can catch, at 0.3 kgs/hr (andcollection is unaffected by having a baby with her). Assume 1 kg ofshellfish is worth 2,000 kcals, and 1 kg of the tiny fish is worth500 kcals. Let’s say the area for collecting shellfish is located12 km from camp, and a Gidjingali woman travels at 4 km/hr when byherself and 3 km/hr when carrying her baby. If a woman has 9 hrstotal to get to the shellfish area, collect shellfish and returnback to camp, then:
(a) what is her expected CALORIC return rate from shellfishcollecting if she goes alone?
(b) what is her expected CALORIC return rate from shellfishcollecting if she goes with her baby?
(c) what is her expected CALORIC return rate from catching tinyfish near camp for 9 hrs?
(d) Based on your answers, when might it be better for a womanto collect shellfish?
2. There are three prey types in the Chuqseja Forest. A tortoiseis worth about 2100 cals, and a hunter can successfully kill itupon pursuit 100% of the time, in 5 minutes. An anteater is worthabout 4300 cals and a hunter can bring it down 80% of the time, butin 30 mins. A brocket deer is worth 35,000 cals, and a hunter canbring it down in 2 hrs, and is successful 25% of the time.
a) What is the profitability (in cals/HOUR) of each of the threeprey types?
b) Let encounter rates (λ) be: λtortoise=2/hr, λanteater=1/hr,λdeer=1/hr. Use the prey algorithm to show me what the optimal dietof a hunter should be.
c) What is the optimal diet if λdeer=10/hr?
d) What would λtortoise have to be in order for the preferencefor anteater to shift?
3. Suppose that the caloric return rates from hunting among theEfe vary by the number of people who participate in the hunt. Thetotal average catch made by a hunting group varies by the huntinggroup size in the following way:
|Group Size||Average Group Catch/Day|
Assume that after a day’s work, the catch is distributed equallyamong all hunting group members.
a) What’s the optimal hunting group size for the Efe (i.e. thatwhich maximizes per capita return rates)?
b) Suppose Efe Band A has 3 members and Efe Band B has 6members. A lone Efe who had come visiting wished to join one ofthese bands. Which of the two bands should be more eager to addanother group member to their band, and why?