Chapter 6 class (exam3) - Chris

Question 1

[Foraging Models]

Optimality Theory

Answer 1

animals use most efficient method to get food. if a foraging model doesn’t work, unidentified variables may be missing from the model.

• eating clay decreases food toxicity (neutralizes bitter diets)

Question 2

[Foraging Models]
Optimize Caloric Intake / Energy Intake
A) what are the variables involved in energy from food?
B) what are the variables of time?

Answer 2

A) search energy
pursuit energy
handling energy
eating energy

B) pursuit time
handling time
eating time

Question 3

Variables in the Prey Model

Answer 3

• Ei energy available from prey
• Hi Handling time for prey
• Si search time for prey.
  Profitability of prey is calculated with these values

Question 4

Marginal Value Theorem

Answer 4

Graphical model dealing with when you should leave one food patch for another.

energy gain in a patch is a curve that initially rises then levels out as you deplete the food

Optimal time to stay is a tangent from graphs origin to the curve
• Example: How long bear stays in berry patch before moving on to new one (how long bear stays depends on distance from next patch. Farther it is, the more they eat before moving on)

Question 5

Predator Effects

Answer 5

elk near wolves spend less time eating in forest and have fewer babies since less time to find food.

Question 6

Strategies for Location and Catching Food

Answer 6

• Waiting: see, smell, hear prey.
• Bait: expend energy to attract prey. aquatic filter feeders bring in food. angler fish.
• Hunting: animals visually seeking fairly abundant prey that are easier to find than others may form a learned search image
• Farming
• Storing: have food and minimize predator exposure when food supply is poor.
• Trapping
• Tool use
• Social Hunting

Question 7

Tool use strategy

Answer 7

use inanimate objects not manufactured internally to alter position or form of another object (ex: sticks, rocks, bark, etc.) allows to catch usually unobtainable prey.

Question 8

Trapping strategy

Answer 8

constructing a trap (in sand) or web

Question 9

Farming

Answer 9

agricultural animals raise plants or animals seeking sites, animals and food for their farms (ants - some ant species raise aphids)

Question 10

Hunting

Answer 10

animals visually seeking fairly abundant prey that are easier to find than others may form a learned search image

Question 11

Bait

Answer 11

expend energy to attract prey. aquatic filter feeders bring in food. angler fish.

Question 12

Storing

Answer 12

have food and minimize predator exposure when food supply is poor.

Question 13

Social hunting

Answer 13

defeats some types of prey resistance.

• may use communication - at least to mobilize group.
• may capture larger prey (6-12x own weight) avoid danger of large animals

example: pack of wolves against buffalo.

Question 14

Social Foraging

Answer 14

• osprey eagles follow successful foragers
• birds - species vary on following successful foragers
• insects - social spiders build communal webs. fire, army and driver ants forage in groups

Question 15

[Food Choice]

Selection

Answer 15

Moose switch on and off of different leaf species to not kill off digestive bacteria (keeping variety)

Question 16

[Food Choice]

Consumption

Answer 16

• Some animals are “dietary specialists” (i.e. Pandas only eat bamboo. Koala bears only eat eucalyptus leaves)
• Some animals will eat clay to counter-act negative impacts of food
• Kangaroo rats can shave outer part of bark and eat interior
• Technique: example of way different birds eat from birdfeeder

Question 17

[Food Choice]

Pollination

Answer 17

• Flower constant - insects visit the same species and enhance pollination

Question 18

[Food Choice]

Food Specialization

Answer 18

warbler birds (3 different types) eat insects from 3 different parts of a tree (top, middle, lower)

Question 19

Niche Rule

[Food Choice]

Answer 19

No 2 species can exist in the same locale and utilize the same resources at the same time.
The less successful of the 2 would either modify its feeding pattern OR be driven to extinction

Question 20

Foraging Specialization

[Food Choice]

Answer 20

Kangaroo rats eat clumps of seeds vs mice looking for individual seeds (same food, but look for it in different ways)

Question 21

Optimal searching

[food choice]

Answer 21

be efficient in looking for food.

minimize time spent looking, pick good spot to search

Question 22

optimal nutrition

[food choice]

Answer 22

get balanced diet that gets species best nutrition

i.e. moose - balancing aquatic plants and tree leaves with sodium.
aquatic plants: high sodium, low energy
tree leaves: high energy, low sodium
dietary constraints: energy, sodium, rumen size (rumen = part of digestive system)