Organismal and Behavioral Ecology

Question 1

Interactions between organisms and the environment limit the

Answer 1

distribution of species

Question 2

Species distributions are a consequence of both ecological and evolutionary interactions through time.
What do we mean by ecological time?
What do we mean by evolutionary time?

Answer 2

The minute-to-minute time frame of interactions between organisms and the environment;

Organisms adapting to their environment over the time frame of many generations

Question 3

How do abiotic factors affect distribution of the saguaro cactus?

Answer 3

Temperature

Question 4

How do biotic factors affect distribution of the saguaro cactus?

Answer 4

Mice and grazers eat the seedlings, and bats pollinate the large, white flowers that open at night. They are also vulnerable to a deadly bacterial disease

Question 5

One factor that contributes greatly to the global distribution of organisms is dispersal.
What is dispersal?
What is biogeography?

Answer 5

The movement of individuals or gametes away from their area of origin or from centers of high population density ;
The distribution of species in the context of evolutionary theory

Question 6

The importance of dispersal is most evident when organisms reach an area where they did not exist previously.
What is the situation with the cattle egret?

Answer 6

200 yrs ago they were only found in Africa and southwester Europe. In late 1800s they crossed Atlantic and colonized northeaster South America. There they spread southward and northward through Central and North America reaching Florida by 1960. Today they are as far west to the pacific coast and as north as Canada

Question 7

What is adaptive radiation? What is the situation with silver swords in Hawaii (see figure 25.22)?

Answer 7

The rapid evolution of an ancestral species into new species that fill many ecological niches;
They have an incredible diversity because of adaptive radiation that was possible only with the long-distance dispersal of an ancestral tarweed from North America

Question 8

To determine if dispersal is a key factor limiting distribution of a species, ecologists may observe the results of intentional or accidental transplants of the species to areas where it was previously

Answer 8

absent.

Question 9

What does it mean to say that a transplant has been successful?

Answer 9

Some of the organisms must not only survive in the new area but also reproduce there sustainably

Question 10

What is potential range versus actual range?

Answer 10

Potential range of the species is large than its actual range or the species could live in certain areas where it currently does not

Question 11

What are some of the consequences of species transplantations?

Answer 11

Can disrupt the communities and ecosystems to which they have been introduced and can spread quickly

Question 12

Does behavior play a role in limiting distribution in such cases?

Answer 12

It can

Question 13

What is habitat selection behavior?

Answer 13

When individuals seem to avoid certain habitats even though they are suitable

Question 14

What is the lack of an appropriate host in areas where an insect could survive otherwise?

Answer 14

Biotic Factor ?

Question 15

How might interactions with predators or herbivores restrict the ability of a species to survive and reproduce?

Answer 15

Limits the distribution of food / kill off the species

Question 16

What’s the deal with sea urchins (herbivores) limiting the distribution of a food species (seaweed)?

Answer 16

Urchins that graze on seaweeds and other algae are common, large stands of seaweeds do not become established. sea urchins are a biotic factor limiting seaweed distribution

Question 17

How about other biotic factors such as presence or absence of pollinators, food resources, parasites, pathogens, and/or competing organisms?

Answer 17

These can also act as biotic limitation on species distribution and are common in nature

Question 18

The next thing to consider is whether abiotic factors might be limiting a species’ distribution. What can they be?

Answer 18

These are temperature, water, oxygen, salinity, sunlight or soil.

Question 19

What’s the situation with temperature?

Answer 19

It is important because of its effect on biological processes. Cells may rupture if the water they contain freezes and proteins of most organisms denature at temperature above 45 degrees C

Question 20

What’s the situation with water and oxygen? What problems might the Paedophryne frog face?

Answer 20

Species living at the seashore or in tidal wetlands can desiccate (dry out) as the tide recess, Terrestrial organisms face a nearly constant threat of desiccation, and the distribution of terrestrial species reflects their ability to obtain and conserve water;
They are particularly vulnerable to drying because they use their moist, delicate skin for gas exchange;
Water affects oxygen availability in aquatic environments and in flooded soils, where the slow diffusion of oxygen in water can limit cellular respiration and other physiological processes

Question 21

What’s the situation with salinity?

Answer 21

The salt concentration of water in the environment affects the water balance of organisms through osmosis; high salinity habitats typically have few species of plants and animals

Question 22

What’s the situation with sunlight? How about at high elevations? Might temperature also be a factor?

Answer 22

Sunlight provides the energy that drives most ecosystems, and too little sunlight can limit the distribution of photosynthetic species;
at high elevations, the sun’s rays are more likely to damage DNA and proteins because the atmosphere is thinner, absorbing less UV radiation;
Too much light can limit survival due to increase temperature stress if animals and plants are unable to avoid the light or to cool themselves through evaporation

Question 23

What’s the situation with rocks and soil?

Answer 23

The pH of soil can limit the distribution of organisms directly, through extreme acidic or basic conditions, or indirectly by affecting the solubility of toxins and nutrients; Composition of rocks and soil that make up the substrate can affect water chemistry, which in turn influences the resident organisms

Question 24

Because adequate nutrition is essential to an animal’s survival and reproductive success, we should expect natural selection to refine behaviors that enhance the efficiency of feeding.
What all does foraging include?

Answer 24

includes not only eating but also any activities an animal uses to search for, recognize, and capture food items

Question 25

With regard to the evolution of foraging behavior, let’s look at an experiment with the fruit fly (Drosophila melanogaster).
What does the gene called forager (for) control? What is the forR allele? What is the forS allele?

Answer 25

dictates how far Drosophila larvae travel when foraging;
The “rover” allele, makes them travel farther while foraging- this occurs during high-density population;
The “sitter” allele, makes them not travel far while foraging- happens in low density population

Question 26

Experiment flies were kept for many generations at either low or high population densities.
What happened in the low population density lines?

Answer 26

More forS alleles displayed

Question 27

Experiment flies were kept for many generations at either low or high population densities.
What happened in the high population density lines?

Answer 27

. More forR alleles displayed

Question 28

What is a cost-benefit analysis? What are the benefits of foraging? What might be the costs of foraging? What is the optimal foraging model?

Answer 28

idea that proposes that foraging behavior is a compromise between the benefits of nutrition and the costs of obtaining food;
These costs might include the energy expenditure of foraging as well as the risk of being eaten while foraging;
natural selection should favor a foraging behavior that minimizes the costs of foraging and maximizes benefits

Question 29

What is the situation with feeding behavior of the Northwestern crow on sea snails called whelks?

Answer 29

The crow gets the snail and flies up and drops it on rocks until its shell breaks open; what is the optimal height for dropping

Question 30

How did the researchers determine the optimal height for dropping whelks that resulted in breaking the shell with the least work?

Answer 30

took the average number of drops required to break whelks from various platform heights

Question 31

What was that optimal height? What was the drop height preferred by the crows? What do these results suggest?

Answer 31

5m;
5.23m;
That the optimal height is what the crows do; this is what determines their behavior

Question 32

One of the most significant potential costs to a forager is risk of

Answer 32

predation.

Question 33

What is the situation with regard to food availability for mule deer?

Answer 33

food availability was fairly uniform across the potential foraging areas, although somewhat lower in open, non forested areas

Question 34

Where is the risk of predation from mountain lions the highest?

Answer 34

at forest edges

Question 35

How does mule deer foraging behavior reflect the differences in predation risk in particular areas?

Answer 35

The feed predominantly in open areas to avoid predation

Question 36

What is a promiscuous mating system?

Answer 36

no strong pair-bonds

Question 37

What is a monogamous mating system?

Answer 37

.one male mating with one female

Question 38

What is a polygamous mating system? What is polygyny? What is polyandry?

Answer 38

.and individual of one sex mating with several of the other;
a single male and many females;
a single female and multiple males

Question 39

What is sexual dimorphism?

Answer 39

the extent to which males and females differ in appearance

Question 40

Why are most birds monogamous?

Answer 40

their young cannot care for themselves; need large continuous food supply that is difficult for a single parent to meet

Question 41

When does polygyny tend to occur in birds?

Answer 41

When the young can care for themselves almost immediately after hatching

Question 42

What’s the deal with many mammals? What about when males protect the females and young (e.g., lions)?

Answer 42

the lactating female is often the only food source for the young, and males usually play no role in raising the young ;
a male or small group of males typically cares for a harem of many females

Question 43

What’s the deal with certainty of paternity?

Answer 43

it is for sure the females offspring but it is not the case for the males

Question 44

What is sexual selection? What is intersexual selection? What is intrasexual selection?

Answer 44

a form of natural selection in which success among individuals are consequence of differences in mating success;
members of one sex choose mates on the basis of characteristics of the other sex (such as courtship songs);
competition between members of one sex for mates

Question 45

What’s the deal with mate choice by females?

Answer 45

plays a central role in the evolution of male behavior and anatomy through intersexual selection

Question 46

How about courtship involving female mate choice of males with longer eyestalks?

Answer 46

it correlates in general with health and vitality

Question 47

The experiment shown in the next slide explored the influence of imprinting on mate choice. What did the experiment show?

Answer 47

female zebra finch chicks that had imprinted on artificially ornamented fathers preferred ornamented males as adult mates

Question 48

What is mate choice copying?

Answer 48

a behavior in which individuals in a population copy the mate choice of others

Question 49

What is agonistic behavior?

Answer 49

an often ritualized contest that determines which competitor gains access to a resource such as food or mates

Question 50

Let’s take a look at the courtship behavior of male fruit flies. Genetic studies have revealed that a single gene called fru controls this entire courtship ritual. What happens if the fru gene is mutated to an inactive form?

Answer 50

males do not court or mate with females

Question 51

Normal male and female flies express distinct forms of the fru gene. What happens if females are genetically manipulated to express the male form of fru?

Answer 51

The court other females, performing the role normally played by the male

Question 52

What type of gene is the fru gene? What is it that genes controlled by the fru gene actually do?

Answer 52

.a master regulatory gene that directs the expression and activity of many genes with narrow functions. Together, genes that are controlled by the fur gene bring about sex-specific development of the fly nervous system

Question 53

Voles are small, mouse-like rodents. How do meadow voles and prairie voles differ with regard to pair bonding and care of young?

Answer 53

male meadow voles are solitary and and do not form lasting relationships with mates and pay little attention to young; male prairie voles form a pair-bond with a single female and hover over their young, licking and carrying them and acting aggressively toward intruders

Question 54

In addition to its role of regulating water retention in kidneys, antidiuretic hormone (ADH) or vasopressin, also plays an important role in

Answer 54

social behavior.

Question 55

What’s the deal with expression of the vasopressin receptor gene in the brain of the prairie mole?

Answer 55

This peptide is released during mating and binds to a specific receptor in the CNS

Question 56

What happened when male prairie voles were treated with a drug that inhibited the brain receptor for vasopressin?

Answer 56

if not expressed they fail to form pair-bonds after mating

Question 57

What happened when researchers inserted the vasopressin receptor gene from prairie voles into male meadow voles?

Answer 57

They started to express many of the same mating behaviors as prairie voles, such as pair-bonding

Question 58

What happened when researchers offered banana slugs to snakes from each wild population?

Answer 58

most coastal snakes readily ate them, whereas inland snakes tended to refuse

Question 59

Researchers then collected pregnant snakes from each wild population and housed them in separated cages in the lab. While still very young, the offspring were offered small pieces of banana slug. What were the results?

Answer 59

More than 60% of the young snakes from coastal mothers ate ban slugs but fewer than 20% of the young snakes f rom inland mothers ate a piece of bank slug

Question 60

What were the two groups of birds that Berthold et al. used in their experiment? What did they do with these birds? What were the results and what did the researchers conclude?

Answer 60

blackcaps that wintered in Britain and blackcaps that wintered in Germany;
Placed in glass cover funnel cages lined with carbon-coated paper for 1.5-2 hours at night. They moved around and marked paper indicated what direction they were trying to migrate;
birds and young from Britain both tried to migrate west while the others tried going southwest; concluded that their migratory orientations are genetic based

Question 61

What is altruism?

Answer 61

.behavior that reduces an animal’s individual fitness but increases the fitness of other individuals in the populations

Question 62

What is the deal with the Belding’s ground squirrel?

Answer 62

a squirrel that sees a predator approach often gives a high-pitched alarm call that alerts unaware individuals to retreat to their burrow; this behavior increases the risk of the squirrel making the alarm to be killed

Question 63

What’s the deal with workers in honeybee societies?

Answer 63

Workers are sterile; they never reproduce, but labor on behalf of the queen; their sing helps defend the hive but results in the death of the workers

Question 64

Altruism is also observed in naked mole rats. What’s the deal with this species?

Answer 64

most of colony consists of nonproductive females and males who will sacrifice themselves to protect the queen or kings

Question 65

How can altruistic behavior be maintained by evolution if it does not enhance the survival and reproductive success of the self-sacrificing individuals?

Answer 65

when they sacrifice themeless for relatives they are increasing the fitness because it maximizes their genetic representation in the population;

Question 66

What is inclusive fitness?

Answer 66

the total effect that an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives, who share many of those genes, to produce offspring.

Question 67

What is sociobiology?

Answer 67

certain behavioral characteristics exist because they are expressions of genes that have been perpetuated by natural selection

Question 68

What are some of the problems with trying to come up with evolutionary explanations of human behavior?

Answer 68

We make laws that define what is acceptable behavior and what is not even if the unacceptable behavior is beneficial for our fitness