Chapter 8: Behavioral Ecology Flashcards
Ethology: the basic study of _____ _____
animal behavior
By focusing on events that take place during an animal’s lifetime, this approach (a “_____ ” question about behavior) seeks to explain behaviors in terms of their _____ or _____ causes.
how
immediate
proximate
By addressing previous events that influenced the features of an animal as we know it today, this approach (a “_____ ” question about behavior) seeks to explain behaviors in terms of their _____ or _____ causes.
why
evolutionary
ultimate
It is usually a _____ to assume that _____ are under the control of one or few _____ . It also _____ to assume that an individual that has an _____ associated with a certain behavior will always perform that behavior.
mistake behaviors genes wrong allele
Instead 2 individuals with _____ alleles may behave _____ . Individuals often _____ their behavior when in different environments. Genes affect behaviors and natural selection molds behaviors over time.
identical
differently
change
Optimal foraging theory best describes the foraging behavior of animals that feed on _____ prey and applies less well to animals feeding on _____ prey
immobile
mobile
P=E/t
Items with high _____ (P) are generally preferred
E = _____ _____ _____ , i.e., energy gained minus energy invested in obtaining & processing the food
t = _____ _____ & _____ _____ invested in obtaining & processing the food
profitability
net energy value
encounter time & handling time
Optimal foraging proposes that animals will maximize the amount of energy required per unit of feeding time. Optimal foraging relies on the assumption that _____ _____ acts on the _____ _____ of animals to maximize their rate of energy gain.
natural selection
foraging behavior
If an animal if foraging optimally and has a choice between two equally abundant food items, it will select the food with the _____ _____.
higher P.
Net energy gained = (Total energy obtained) – (Cumulative energy investment) Drops off as animal cannot carry nor ingest more
At first, the total amount of energy that an animal obtains from its food _____ _____ with the effort it invests – that is, with the time and energy it spends searching for, capturing, subduing, and consuming food.
At some point, however, a further increase in foraging effort provides relatively little additional energy, and the net energy gain begins to decrease. Several factors may cause this _____ , including a limitation on how much food the animal can carry or ingest.
increases rapidly
decrease
Marginal Value Theorem as applied to _____ of _____ _____ :
Within a patch, the marginal value for longer time has _____ returns
Slopes of straight, solid lines = Energy gained / time
Tangent maximizes profitability (slope) & determines _____ giving up _____
profitability of foraging patches
diminishing
optimal
time
Marginal Value Theorem can be used to evaluate the influences of distances between _____ , the quality of the _____ in a patch, and the animal’s energy _____ _____ on the giving up time.
patches
food
extraction efficiency
Marginal Value Theorem has also been extended to other “giving up” problems in behavioral ecology, including how long to _____ and when to _____ guarding a nest and seek other mates.
copulate
cease
Marginal Value Theorem assumes that a foraging animal will _____ patches containing varying amounts of food. The animal’s rate of energy gain in a patch is initially _____ but _____ as the animal _____ the food supply in the patch. The time the animal spends in a patch should optimize its rate of energy gain.
encounter
high
decreases
depletes
Foraging (and other) decisions can be modified by _____
Prey sometimes _____ their _____ of predators to those predators. E.g., stotting / pronking
predators
communicates
awareness
There is a wide variety of ways that prey seek to prevent attack once they are seen.
When threatened some prey make sudden movements or place their body in positions that startle a predator. Some prey send predators a signal, in effect conveying, “____ ____ ___, I’m faster than you, ____ ____ ___ ____ ____.”
“I see you,
so don’t bother to attack me.”
Members of a ____ can enjoy higher reproductive success than ____ ____
As the number of individuals in a group increases, the chance of being the one attacked decreases.
group
solitary individuals
Main Advantages of living in a group: access to ____ , protection from ____ , and improved ____ success.
Other benefits include gain access to good breeding sites or abundant supplies of food, and shared responsibilities if feeding and protecting the young.
mates
predators,
foraging
Main Disadvantages of living in a group: greater ____ ____ , more ____ for food, and higher risk of ____ .
energy expenditures
competition
disease.
Groups should be a size at which the benefits of belonging to a group exceed the costs.
Optimal size – the size at which the net benefits received by its members are maximized; the observed group however can be ____ than the optimal size
larger
Sexual selection is a process in which individuals with certain characteristics gain an ____ over others of the same sex solely with ____ to ____ ____ .
Sexual selection can be considered competition for gametes.
advantage
respect to mating success.
Competitive males and choosy females result from greater female investment in offspring;
the reverse occurs when there is greater male investment in offspring.
In species in which ____ invest more in their offspring than ____ do, we would expect ____ to be choosy and ____ to compete for the right to mate with females.
Since ____ invest relatively little per offspring produced, we would expect that ____ could produce more offspring during their lifetime than ____ could.
females
males do
females
males
males
males
females
direct benefits
nuptial gifts
gifts of food, help in rearing the young, or access to a territory that has good nesting sites, abundant food, or few predators.
indirect benefits
good genes
The sexy sons hypothesis: females receive indirect genetic benefits through their sons, who will themselves be attractive to females and produce many grandchildren
The males that do the ___ job at copulatory courtship are the ones that get ___ and are ___ by females.
best
chosen
favored
Mating system refers to the number of mating partners that males or females have and the pattern of parental care.
Mating systems can vary among closely related species and among individuals within a population of a single species.
Monogamy -
male mates with one female. Both parents care for young. Not much variation in reproductive success.
Polygyny –
male mates with multiple females. Male may control females directly or indirectly. Females care for young. In polygynous mating systems there are “floater” males. “Polygyny occurs if environmental or behavioral conditions bring about the clumping of females, and males have the capacity to monopolize them.” Emlen & Oring (1977). There’s a dramatic variation in reproductive success for males.
Polyandry –
female mates with multiple males. Female may defend males directly or indirectly. Males care for young. In polyandrous mating systems there are “floater” females. There’s a dramatic variation in reproductive success for females.
Promiscuity –
both males and females mate with multiple partners. Anything goes.
A general schema of the determinants of a mating system:
Low potential for polygyny: females are spread evenly throughout the environment.
High potential for polygyny: females clump together in some regions of the environment.
Pick a point on the monogamous female curve. The distance to the right to intercept the bigamous female curve is the polygyny threshold, i.e., the habitat quality increase required to make it worthwhile for the female to share a mate.
Polygyny threshold is the minimum difference in quality of habitat held by males in the same general region sufficient to make bigamous matings by females favored by natural selection.
Kin selection exposes the selfish nature of ___; helping kin can ____one’s inclusive fitness (direct plus indirect fitness)
Hamilton’s Rule: rB > C
Relatedness * (Benefits to recipient) > (Costs to altruist)
altruism
increase
Relatedness
r – introduced by Sewell Wright as a measure of ___
Each connector is mediated by a ___(i.e., half of the donor genes to the recipient).
Niece-Aunt – r = [1/8+1/8] = ¼
consanguinity
gamete
Eusociality in Diploid Organisms
For most individuals in the colony the benefits to helping the ____ outweigh the costs of sacrificing their own reproduction
rB > C
queen
Eusociality in Haplodiploid Organisms
For most female individuals in the colony the benefits to helping the queen ____ ____ outweigh the costs of sacrificing their own reproduction
rB > C
rear sisters
Haplodiploid sex determination - males (haploid) develop from ____ eggs; females (diploid) develop from ____ eggs.
unfertilized
fertilized
Father is related to each daughter with r=__
Daughter is related to her father (or mother) with r=__
A female is related to her sister with r=__
Accordingly, it pays a sister to help her sister more than her own offspring.
1
1/2
3/4
