Midterm 2

Question 1

Advantages of matrices over exponentila/logistic growth models

Answer 1

Sensitivety analysis

Elasticity analysis

Can model a greater diversity of life historie

Age structure exists

Explicity based on assumptions of variation in l_xand b_x(f_x) among age classes

Question 2

Finite rate of increase

Answer 2

Lambda=R+1

Question 3

Main goal of leslie matrix?

Answer 3

Calculate finite rate of increase

Question 4

What is a vector and a scalar?

Answer 4

Vector: matrix with only one row of column

Scalar: is a single number

Question 5

Primary subDiagonal?

Top row of leslie matrix?

Answer 5

Top row: fecundity of each age class

Primary subdiagonal: age specific survivorship

Question 6

F_{x in regards to a matrix?}

Answer 6

Per capita output of new young by age class. Called fertility (px*bx)

Question 7

How do you convert a life table to a leslie matrix?

Explain post and pre breed differences.

Answer 7

Need to calculate p_x and fx

Post breed:

p_x=l_x+1/l_x

f_x=(p_x)(b_x+1)

Pre breed:

p_x=l_x+1/l_x

f_x=(p₀)(b_x)

Question 8

Output of a leslie Matrix?

Answer 8

1. Population size at each successive time step
2. Age class structure
3. Calculation of lambda=N_t+1/N_t
4. Continued calculation of lambda using the matrix, b/c assumes unchanging l_xand f_x, generates eventually the Lambda in N_t+1=lambdaN_t Known as asymptotic growth rate
5. Once AGR is attaine lambda does not change, pop attains SAD.

Question 9

What is a Lefkovich Matrix?

Answer 9

Identical to Leslie matrix except:

1. idividuals can stay within an existing stage or transition forward or backward
2. lambda is still calculated but SSD is attained insteas
3. boasts small data sets.

Question 10

What do the various rows in a Lefkovich matrix mean?

Answer 10

Question 11

What are Px and Gx in relation to a Lefkovich matrix?

Answer 11

Px= probability that in individual will survive and remain in the same stage or size class in the next time unit.

Gx= probability that an individual will survive and move up to the next stage or asize class in the next time unit.

Question 12

Quick way to calculate mortality in Lefkovich matrix?

Answer 12

mortality= 1-(probability of advancing+probability of remaining)

Question 13

What are sensitivity and elasticity analyses?

Answer 13

Sensitivity determines how very small changes in each variable, while holding all others constant, affect lambda

Elasticity scale sensitivity to units. Proportional sensitivities scaled so that they are dimensionless and directly comparable.

Question 14

Describe methods for calculating sensitivity an elasticity analyses.

Answer 14

_{<span>Determine right eigenvector (w)= run matrix till SAD, then calculate proportion of each age class…this is (w)</span>}

_{<span>Next determine left eigenvector (v) this is reproductive value measurement. </span>}Transpose original matrix and complete normal matrix analysis. Represent each age class as a proportion. Standardize by dividing each element by p’_o.

Sensitivty (v_iw_i)/ (

See image 1

Elasticity

Question 15

What are some properties that same species regularly exhibit

Answer 15

• variation in Neq among sites
• stable numbers at anyone site when viewed on the short-term
• long term change not uncommon

Question 16

Describe the difference between regulation and limitation.

Answer 16

Limitations are typicall phycial factors. Otherwise known as a cap

Regulation is typically biotic factors.

Question 17

what are the two principles of basic model of population regulation?

Answer 17

No population stops growing unless percapita B or D rates decline with density

Differences in density can arise from variation in D-D or per capita B and D. (emigration and immigration is important)

Question 18

What is a sink?

Answer 18

a population that persists over long periods of time despite contradicting birth and death rates (BIDE models). due in part to immigration from other populations.

Question 19

What is ideal-free?

Answer 19

Ideal free is a distribution pattern that individuals distriubte themselves across a resource gradient that is proportionate to the amount of resource per area. Greater resource= more animals. This is a way to minimize resource competition for resources and to maximize fitness.

Question 20

What does Ideal-despotic distribution mean?

Answer 20

distribution occurs when hab selection is controlled by territorial behavior

Question 21

elements need to determine reproductive rate?

Answer 21

of bouts

number/bout

Annual frequency

%breed-cost of reproduction

Age specific effects

Question 22

Estimate “apparent mortality”?

Answer 22

Apparent mortality= P_{death +}P_emigration+P_sighting

Question 23

What does Z_igive in a statistical mark-recapture model??

Answer 23

Z_i=number marked before time i, not caught in i, but are caught at a later time.

Calculated by summing rows i+1

Question 24

What does φ signify?

Answer 24

φ is apparent survival

φ=[M_i+1]/[M_i-m_i+R_i]

Prop. survive = (# marked from time period 2 alive before current sample [3]), divided by (# marked from time period 1 & alive at start of period 2, less # marked in time period 2, plus # released in sample 2 after marking)

Question 25

How many years of data do you need to perfom a Cormack Jolly-seber model?

Answer 25

3. Interested in annual survival, robust design has shorter time intervals built into a large time frame.

Question 26

How do you estimate survival from age class composition?

Answer 26

Calculate finite annual survival Assumes: survival rate constant for each age class, all year-classes recruited at same abundance, all classes sampled equally S=(T)/R+T-1 R=ΣNt T=N1 + 2N2 + 3N3 + ….

Question 27

What are catch curves?

Answer 27

Often used in fisheries. Blue box is estimation of mortalit, overall measurement of adult survival. Multiple assumptions.

Question 28

How do calculate S from a catch curve?

Answer 28

S=e^slope

Question 29

what is the Kaplan-Meier estimate of survival?

Answer 29

It is a known fate model: allows for (a) multiple sample intervals, (b) staggered entry, (c) right censoring of data. RT good example

Question 30

How do you calculate S in a Kaplan-Meier model?

Answer 30

S_t+1=S_t(1-(#dead/#@risk)) Can also multiply probabilites of times leading up to year wanting to calculate

Question 31

Can convert long term survival rates to daily survival rate. How do you do this?

Answer 31

Question 32

Can populations be regulated?

Answer 32

The is inherent variability introduced by a) environmental stochasticity, b) demographic stochasticity, c) internal biotic limitations (time lags) and an uncertainty over appropriate scale of mearsurement. It is essential distinguish between limitation and regulation.

Question 33

Is regulation a DD response?

Answer 33

Yes!

Question 34

How do you establish if and how regulation is occurring?

Answer 34

a) do B and D rates vary with N, and, do patterns differ among age/sex groups? b) identify causes for variation in B and D rates, what are mortality agents? c) Does population show negative feedback?

Question 35

Why is DD difficult to determine?

Answer 35

(a) analyses of populations in which N is to low to detect it, (b) conducting studies for to brief a period (c) failure to include non-breeders in estimates of N (d) inappropriate measures of density (#/area vs. #/food supply) (e) difficulty of separating biotic and abiotic factors (e.g. severe winter weather and food) (f) inherent difficulty of estimating population size and survival rates (g) need to view populations on larger spatial scales (metapopulations) (e) density responses due to numbers of other species

Question 36

Explain additive mortality

Answer 36

Additive mortality is when mortality agent acts independently of other sources of mortality and thus increases the rate of mortality when added to the system, such as predation.

Question 37

Explain compensatory mortality.

Answer 37

When one source of mortality replaces another and a population stabilizes.

Question 38

What is a Key-Factor Analysis?

Answer 38

An extension of a life table. Best used on species with discrete life stages life insects. Calculation of (K_x ) which is total mortality, or generation mortality.

Question 39

How do you calculate K_x?

Answer 39

K=Σki=ki=log(Ni)-log(Ni+1) sum of k values equals K.

Question 40

How do you test to see if mortality is DD in a Key factor analysis model?

Answer 40

Plot K vs N across years, increase if indicator of DD.

Question 41

With what organisms is a KF analysis best used?

Answer 41

Best applied to organisms without overlapping generation, key factor driving pop change no always DD and doesn't always result in regulation, Plots of key factors against N can yield useful information on strenght of DD, time lags and other phenomena.

Question 42

What do different slopes of key factor analyses mean? example when b\>1? etc..

Answer 42

1=b perfect compensation b\>1 over compensating b\< under compensating -b inverse density dependence circular=delayed density dependence scatter=density independent

Question 43

what is self-thinning?

Answer 43

Reduction in density (through mortality) as a consequence of the increased mean weight of individuals when growth is constrained at high densities.

Question 44

What is reproductive suppression?

Answer 44

Largely associated with mammals. As density increases greater proportion of females stops breeding. Likely hormornally induced. Found that food influences rate at which nonparous is exhibited.

Question 45

Name the 7 types of interactions between species

Answer 45

Competition, Parasitism, Mutualism, Predation, Disease, Facilitation, Herbivory

Question 46

Explain interspecific competition

Answer 46

Competition for the same resource between different species

Question 47

Explain intraspecific competition

Answer 47

Competition between individuals within the same species

Question 48

What is exploitative and interference?

Answer 48

Exploititive competition is when one species is better adapted at utilizing a resource than the other. Interference is when a species actually physically interfers with a competitor ability to utilize a resource.

Question 49

What is competitive exclusion?

Answer 49

Guase 1934: One species ultimately excludes the other in a closed setting with limited resources and at constant pop values.

Question 50

Autoecological vs. synecological?

Answer 50

auto is single organism level and syecological is population level.

Question 51

What is a niche?

Answer 51

Widely defined. Hutchinson--\>fundamental vs. realized Elton--\> Where the species fits in the environmental web. Has evolved over time.

Question 52

Where should we find competition to be potentially most common?

Answer 52

Closely related species (similar size, morphology, physiology, and activity patterns).

Question 53

What is resource partitioning?

Answer 53

The division of a resource between two competitors in order to reduce competition. Example tropical lizards.

Question 54

What is character displacement?

Answer 54

This is a result of resource partitioning. Character displacement is when a species co-occur in distribution their differneces are extenuated but when they are isloated differences are not as prominent. Due to competition of same resource.

Question 55

What did Hutchinson say about species coexisting with one another?

Answer 55

He said that if species differed in size with a ratios of at least 1.3 they could coexist. Leads to exploitation of differend resource. Avoidance of competition.

Question 56

What is the unutilized portion of the environment?

Answer 56

(K-N)/K

Question 57

Lotka-Volterra Equations

Answer 57

N1 =K1 –αN2 N2 = K2 – βN1

Question 58

Explain unstable equilbrium

Answer 58

Alpha and beta values are \> 1.0 therefore interspecific competition is stronger than intraspecifc.

Question 59

Stable equilibrium is?

Answer 59

Alpha and beta are both \<1.0 therefore interaspecific competition is stronger than interspecific

Question 60

What do L-V competition models assume?

Answer 60

1) all assumptions inherent to the logistic model DD is linear, all individuals are exactly alike, K constant, no time lags, closed pop, no abiotic sources of mortality 2) Resources are limited 3) Competition coefficients are constant

Question 61

δ γ represent what in L-V competition models?

Answer 61

Interaction coefficients

Question 62

What is intraguild predation?

Answer 62

Two competing species who also interact as predator and prey.

Question 63

Answer 63

An indirect affect of competition between A and C due to the competition between C and B.

Question 64

Prey switching. What is it? Provide an example.

Answer 64

Prey switching is when a predator utilizes a certain species at a particular density and then switches prey when density drops too low. Example is the Arctic fox, arctic goose an the lemmings.

Question 65

What types of predators are there?

Answer 65

Carnivores, parasites, herbivores, cannibals, parasitoids. Easily observed and quatified.

Question 66

What does predation have impacts on?

Answer 66

community structure, evolutionary force, weak and sick animals,

Question 67

What is bottom up regulation? What is top down regulation?

Answer 67

Bottom up regulation refers to limits in abundace of species due to low trophic factors such as food supply Top up is the negative affect of predators and/or parasites and competition.

Question 68

What is the equation for prey continuous generation model? What do each variable stand for?

Answer 68

dN/dt=rN-aNP r=growth N=pop size a=efficiency of search and attack by predator NP=encouter rate between the two.

Question 69

What is the equation for predators in a continuous generation model? what does each variable mean?

Answer 69

dP/dt=f(aNP)-qP q=per capita starvation rate f=converting prey into new predators aNP=rate of food consumption always\<1.0 a=efficiency of search and attack by predator

Question 70

How do prey and predators respond to each other? How do we show this graphically?

Answer 70

Create state space diagrams using P=r/a N=q/fa (P=predator, N=prey)

Question 71

what does r/a and q/fa represent?

Answer 71

r/a=ratio of growth rate of prey to capture efficiency of predator q/fa=ratio of death rate of predators to efficiency of capturning (a) and turning prey into predators(f) q is per capita starvation rate

Question 72

Draw a modified prey isocline as described by Rosenzwig and MacArthur. What did it add to the idea?

Answer 72

It adds realism. All along the curve dN/dt=zero.

Question 73

What is a refuge? and what does it look like graphically?

Answer 73

Area where a prey species can persist in the presence of the predator indefinetly.

Question 74

What is a time lag in regards to predator prey models?

Answer 74

Time lags-logistic assumes instantaneous response on part of populations to changes in resources. Creates instability, leads to probable extinction for one or both species.

Question 75

What is the difference between an "efficient" and "inefficient" predator?

Answer 75

"Efficient" predator keeps prey well below K "Inefficient" predator results in prey regulating near K

Question 76

What does the term "paradox of enrichment" mean?

Answer 76

Rosenzweig 1971 coined the term to describe the instability of predator populations caused by an added influx of food to prey populations. Lynx and the hare is a good example, an added abundance of rabbits causes the lynx populations to grow to an unstable number and will lead to eradication or a significant drop in numbers.

Question 77

Why do refuges exist?

Answer 77

a)true spatial refuge, b)aggressive behavior of prey, c) a strong type III response, d) a fixed number of immigrants (pseudo refuge)

Question 78

Describe each of the curves shown.

Answer 78

1=standard L-V 2=predator population increases w/prey 3=self limitation due possibly to interference 4=predator population limited by own predators or other factors

Question 79

When does a predator exist completely independently of prey? What does the isocline look like?

Answer 79

When intraspecific competition and prey switching are prevalent.

Question 80

Cycling behavior leads to what in LV predator prey models?

Answer 80

Clockwise fashion cycling typically leads to stabilization Counter clockwise tend to be de stabilizing. The more independent the predator and prey are of one another the more stable the system's dynamics.

Question 81

Predator responses to changes in prey density. What are the two types of responses, and what do these responses entail?

Answer 81

Numerical- Immigration and reproduction Functional- Change in prey consumption patterns: Type 1 Linear rise in consumption rate as prey density increases Type II A decelerating rise in consumption rate, eventually asyptotes slope of line =a from LV equation. (invertabrate curve) Type III Sigmoidal shape that also attains an asymptote (vertebrate curve)

Question 82

What kind of predator response does this graph show?

Answer 82

Numerical

Question 83

what response does this graph represent?

Answer 83

Type II functional response

Question 84

What type of response does this graph show?

Answer 84

Type III functional response

Question 85

Is this a numerical or functional response?

Answer 85

Numerical, because of the linear relationship.

Question 86

Is this a functional or numerical response?

Answer 86

Functional type III response

Question 87

Describe each type of functional responses.

Answer 87

Type I: effective at all population densities of prey Type II: effective at low densities, but unable to limit prey at high densities (destabilizing) Type III: effective at low densities, but ineffective at high densities (destabilizing)