Behaviour ecology 51 Flashcards
Biologists analyze behaviour at the proximate and ultimate levels _____________________ and how they affect fitness.
the genetic and physiological mechanisms
Individuals can behave in a wide range of ways; which behaviour occurs depends on ____________________________
current conditions
Foraging patterns may vary with genotype; foraging decisions maximize ___________ and minimize _______
energy gain
costs
[*] Sexual behaviour is affected by levels of sex hormones; females choose mates that provide ______________________________
good alleles and needed resources.
Animals navigate using an array of cues;
name them
the costs of migration can be offset by benefits in food availability
[*] Animals communicate with ___________________; communication can be honest or deceitful.
movements, odours, or other stimuli
[*] Individuals that behave ___________ are usually helping relatives or individuals that help them in return.
altruistically
define behaviour
Behaviour is action—a response to a stimulus.
Ecology is the study of ____
how organisms interact with their physical and biological environments
•behavioural biology is - what
the study of how organisms respond to particular stimuli from those environments. The action in behaviour is this response.
•Behavioural ecologists ask questions and test hypotheses at two fundamental levels—
proximate and ultimate.
•To understand why animals and other organisms do what they do, researchers have to ask questions about ______
genetics, hormonal signals, neural signalling, natural selection, evolutionary history, and ecological interactions.
•Proximate - define
(or mechanistic) causation explains how actions occur.
•Ultimate - define
(or evolutionary) causation explains why actions occur.
Efforts to explain behaviour at the proximate and ultimate levels are complementary. To understand what an organism is doing, biologists want to know
how the behaviour happens and why
•Fixed action patterns (FAPs) are
highly inflexible, stereotypical behaviour patterns.
FAPs are examples of ______________, behaviour that is inherited and shows little variation based on learning or the individual’s condition
innate behaviour
[*] Most animals have a range of actions that they can perform in response to a situation. Animals take in information from the environment and, based on that information, make decisions about what to do.
•
•This kind of behaviour is called _______________________
condition-dependent behaviour.
To link condition-dependent behaviour to fitness, biologists use a framework called _________________
cost-benefit analysis
–Costs and benefits are measured in terms of their impact on
fitness —the ability to produce offspring.
•When animals seek food, they are _____________.
foraging
•To understand why individuals eat the way they do, consider:
- research on genetic variation in foraging behaviour and
- the costs and benefits of feeding at various distances from home.
•Fruit-fly larvae exhibit one of two behaviours during feeding.
–“Rovers” move after feeding in a particular location.
–“Sitters” stay in one location to feed.
•Experiments determined that this feeding behaviour is inherited via the ____________
foraging (for) gene.
[*] When biologists set out to study why animals forage in a particular way, they usually start by assuming that individuals make decisions that maximize the amount of usable energy they take in, given the costs of finding and ingesting their food and the risk of being eaten while they’re at it.
•
•This claim is called
optimal foraging.
•Sex hormones—testosterone in males and estradiol in females—are the _______________ cause of dramatic seasonal changes in behaviour.
proximate
Sexual Activity in Anolis Lizards
•A series of experiments indicate that two types of stimulation are necessary to produce the hormonal changes that lead to sexual behaviour.
Females need to experience ____________________________________
spring-like light and temperatures, as well as exposure to breeding mates
•Males signal females and induce estradiol release by exhibiting a________________. When males court females, they
specific mating signal
bob up and down and extend a brightly coloured patch of skin called a dewlap.
•Although both male and female barn swallows help build the nest and feed the young, the species exhibits a significant amount of______________—males are slightly larger and more brightly coloured, and their outer tail feathers are about 15 percent longer than the same feathers in females.
sexual dimorphism
•Experiments supported the hypothesis that female barn swallows prefer long-tailed mates.
Why?
–Long-tailed males are more efficient in flight and more successful in finding food, and thus have higher fitness.
He will also pass high-fitness alleles on to her offspring and be able to help her rear those offspring efficiently
•Animals usually make decisions in a way that maximizes their fitness.
•There are many questions related to habitat selection:
list them:
–Should juveniles disperse from the area where they were raised?
–How large of a territory should be defended against competitors.
–How do habitat density and quality affect fitness?
•migration — define
the long-distance movement of a population associated with a change of seasons—relates to these questions of habitat selection.
Biologists distinguish three categories of navigation
list them
1.Piloting is the use of familiar landmarks.
●
2.Compass orientation is movement oriented in a specific direction.
●
3.True navigation is the ability to locate a specific place on Earth’s surface.
Piloting
is the use of familiar landmarks.
Compass orientation
is movement oriented in a specific direction.
True navigation
is the ability to locate a specific place on Earth’s surface
•a 24-hour rhythm of chemical activity. The clock is set by the light-dark transitions of day and night and tells an animal enough about the time of day that it can use the Sun’s position to find magnetic north.
circadian rhythm
•At the ultimate level, why does migration exists
because individuals that migrate achieve higher reproductive success than individuals that do not migrate.
[*] Increased access to food is a benefit of migration. There is a high cost, however, in time, energy, and predation risk.
what is the cost of migration?
high cost, however, in time, energy, and predation risk
•Communication is a process in which_______…
a signal (any information-containing behaviour) from one individual modifies the behaviour of another individual.
•Communication is a social process. For communication to occur, it is not enough that a signal is sent;
the signal must be received and acted on.
•
proximate mechanism of communication of honey bees
Von Frisch found that both the round dance and the waggle dance communicate information about food sources
He observed bees displaying a “round dance” to workers, as well as a “waggle dance
hoeny bees
•Recent work has shown that the round and waggle dances are actually the same type of behaviour—round dances just have a short waggle phase.
•The orientation of the waggle portion of the dance correlated ___________________________________________
_______________________________
with the direction of the food source from the hive, and the length of the straight waggling run was proportional to the distance the foragers had to fly to reach the food.
•This dance also communicated the position of the food relative to the current position of the Sun.
Several modes of communication are often used together. list the four modes
tactile
olfactory
acoustic
visual
The type of signal an organism uses correlates with its habitat
•Most behaviours help individuals respond to environmental stimuli such that they can maximize their own fitness. __________, behaviour that has a fitness cost to the individual exhibiting it and a fitness benefit to the recipient, appears to contradict this pattern.
Altruism
Altruism
•
•Altruism decreases an individual’s ability to produce offspring but helps others produce more offspring.
•
•The existence of altruistic behaviour appears to be paradoxical; alleles that make an individual more likely to be altruistic should be selected against.
•Hamilton’s rule states that altruistic behaviour is most likely when three conditions are met:
- The fitness benefits of altruistic behaviour are high for the recipient.
- The altruist and recipient are close relatives.
- The fitness costs to the altruist are low.
Hamiltons’s rules
What does it mean when the individuals have an r = 0?
r = 1
•The coefficient of relatedness, r, varies between 0.0 and 1.0.
–If two individuals have no identical alleles that were inherited from the same ancestor, then their r value is 0.0.
–Because every allele in pairs of identical twins is identical, their coefficient of relatedness is 1.0.
•Hamilton’s rule is important because it shows that individuals can pass their alleles on to the next generation not only by having their own offspring, but also by _________________
helping close relatives produce more offspring.
•_________________ display extreme forms of altruistic behaviour and kin selection. These animals live in social colonies in which only a few individuals reproduce, while the rest are sterile workers that support the colony.
Eusocial animals
–In some eusocial insects a haplodiploid mechanism of sex determination leads to
a very high coefficient of relatedness (r).
–Naked mole rats are _______, a colony includes 70 or 80 mostly sterile, hairless, blind rodents, with only one female who reproduces with a few related males resulting in a high r.
eusocial
Direct fitness
–Direct fitness is derived from an individual’s own offspring.
Indirect fitness
Indirect fitness is derived from helping relatives produce more offspring than they could produce on their own
•The combination of direct and indirect fitness components is called ______________
inclusive fitness.
•_________________ is natural selection that acts through benefits to relatives and results in increased indirect fitness.
Kin selection
in prairie dogs
•The kin-selection hypothesis predicts
that individuals who do not have close genetic relatives nearby will rarely give an alarm call.
Most cases of self-sacrificing behaviour that have been analyzed to date are consistent with _____________and are hypothesized to be the result of kin selection
Hamilton’s rule
Reciprocal altruism
- Reciprocal altruism is an exchange of fitness benefits that are separated in time.
- Reciprocal altruism is also widely invoked as an explanation for the helpful and cooperative behaviour commonly observed among unrelated humans.
•You should be able to
–Determine the proximate and ultimate causation of a behaviour.
–Explain how the changes in day length trigger changes in sex hormones in Anolis lizards.
–Design an experiment to determine if barn swallow tail length affects female choice of mate.
–Describe how animals find their way on migration.
–Describe how deceitful communication can be adaptive.
–Calculate the coefficient of relatedness.
–Explain how altruistic behaviour increases the fitness of individuals.
Are plants, fungi, protits and bacteria capibible of behaviour?
give examples
behaviour is responce to stimulus
plants grow to the sun
stem collapsing in response to touch
