Chapter 3 Behavioral ecology Behavior: The ways that organisms respond to each other and to particular cues in the environment Cost- benefit analysis Optimal foraging: any method of searching for and obtaining food that maximizes the relative benefit. Promiscuity: multiple mating (난혼) Trade-offs: Compromises between two desirable but incompatible activities

Chapter Opener 8 species of flamingo

Monogamy: <3% in mammal Promiscuity is very common in mammal Figure 3-1 Monogamy: <3% in mammal Promiscuity is very common in mammal Promiscuity of Ethiopian wolf Female wolves decide which males they will copulate with,

Paternity Confusion Trade offs Figure 3-1B Promiscuity in mammals is often an attempt to confuse paternity Males from packs can attack juveniles in adjacent packs if they are not genetically related. Paternity Confusion Cost-benefit analysis: economics term for project Cost: energy consumed, the probability of injury, or being killed by predator Benefit: net gain in energy or increase in reproductive success Trade offs

Larger areas are more expensive to defend Figure 3-2 An animal’s territory is any defended area. The benefit of defending territory is exclusive access to food. Cost-benefit model for territory size in animal Larger areas are more expensive to defend

Territory defended by hummingbirds in relation to flower density Figure 3-3 Territory defended by hummingbirds in relation to flower density Individuals always defended the same number of flowers regardless of the size of territory (Arizona)

Daily weight change of one marked hummingbird (California) Figure 3-4 Defend the territory And less time feeding rufous hummingbird Daily weight change of one marked hummingbird (California) The cost of defending a large territory would exceed the benefit of having more food available. Sierra Nevada of California

Optimal foraging –any method of searching for and obtaining food that Figure 3-5 Skip Optimal foraging –any method of searching for and obtaining food that maximize the relative benefit

Gerbils are nocturnal, seed eating rodent. Major predator: barn owl Figure 3-6 Gerbils are nocturnal, seed eating rodent. Major predator: barn owl

Optimal Migration: Time minimization, Energy minimization Figure 3-7 Optimal Migration: Time minimization, Energy minimization skip Early arrival Migratory period only The amount of fat and protein expressed as a fraction of lean body mass Annual base Rate of energy accumulation by feeding before migration begins and stopover

Whooper swan

Best fit: Time minimization model The time spent in stopovers is about Figure 3-8 2500 km of desert (Sahara) Best fit: Time minimization model The time spent in stopovers is about 7 times that spent on flight for small bird

Table 3-2 Group living

-The direction and duration of straight runs Figure 3-9 -The direction and duration of straight runs in the dance are closely correlated with the direction and distance of the patch of flowers just visited. -Bees routinely forage up to 12 Km from their nest. Social insects are the classic example of cooperartion for food gathering

The farther away the target, the longer the straight-run part of the dance.

Second potential benefit of group living is a Figure 3-10 Second potential benefit of group living is a reduced risk of predation. Guppies in Trinidad streams: When predators are abundant, guppies school in more tightly spaced group. Cohesion score is based on how much individual fish spaced from one another

Figure 3-11

Puffin lays a single egg: Why not two eggs? Unnumbered Figure 3-1 Puffin lays a single egg: Why not two eggs? More to lay two eggs, fly more to feed two young

KIN SELECTION Predators: coyotes, pine martens long-tailed weasels Figure 3-12 Predators: coyotes, pine martens long-tailed weasels Females were far more likely to give alarm calls than males.- (a) Kin selection (b) The evolution of traits that increase the survival, and ultimately the reproductive success, of one’s relatives rather than oneself is termed KIN SELECTION

Cost of group living Magellanic penguin up to 200,000 Figure 3-13 Cost of group living Magellanic penguin up to 200,000 Nitrogen index is indicator of food quality (stable nitrogen isotopes)

Incubation success is the ratio of the number of nests at hatching Figure 3-14 Incubation success is the ratio of the number of nests at hatching in Feb/ nests at laying in Nov.

Group living in African Lions Figure 3-16 Group living in African Lions Lion distribution Pride= 1 to 7 males 2 to 18 females + their young Small pride-desert Large pride-Serengeti, more prey Female almost never leave the pride in which they were born.

Benefit of group living in male lions Male – male competition Figure 3-16 Benefit of group living in male lions Male – male competition Males that take over a pride kill unrelated cubs.

Larger groups facilitate territorial defense, which is important Figure 3-17 Optimal group size Larger groups facilitate territorial defense, which is important in preventing male takeovers. When new male take over a pride, they typically kill all young cubs.

Table 3-3

Table 3-1 skip

Figure 3-15 skip