FW 453 Final
a common measure that quantifies parsimony
Akaike's Information
Violations of equal detection in closed captures
- trap happy - trap shy
True/False An estimate with high precision will also be highly accurate
False; estimates can be measured precisely , but to ensure accuracy you need to have a control, remove bias, and ensure randomization
True/False The top row of a pop. projection matrix contains only litter size or clutch size, but no survival
False; fecundity rates
True/False The Cormack Jolly-Seber model allows for modeling trap happiness.
False; looks at apparent survival and detection probability (Phi and p)
True/False Positive density dependence tends to stabilize populations.
False; positive density dependence destabilizes populations. It causes very small populations to crash, and increases growth rate with growing densities.
True/False Resource preference in animals is something commonly estimated in the field.
False; preference is very difficult to estimate. All resources must be available in equal amounts to determine preference
True/False In stratified sampling, the sampling locations are placed in areas with lots of individuals or where they are "clumpy"
False; this describes cluster sampling
Name one difference between CJS models and Jolly-Seber models?
JS allows you to estimate population size (aka abundance and recruitment)
Key design issue with site occupancy
Replication
True/False An estimate requires both a model and measure of uncertainty?
True
True/False Even in a completely constant environment, with mean vital rates remaining constant, a population could fluctuate wildly in numbers due to demographic stochasticity or due to stage structure being very different from stable stage structure.
True
Which of the following is NOT an advantage of stratified sampling? a. It controls for a heterogeneous study area b. It allows for estimation of density by each individual strata c. It requires a larger total sample d. It provides a more precise estimate of overall density
c. It requires a larger total sample
Name at least one of the two factors that can lead to a variable population growth rate.
chaotic dynamics; or any of the the deterministic stressors
Virtually all abundance estimates for wildlife populations arise by dividing a count of animals by what?
detection probability (p hat)
inability to state an average system response to an action
scientific uncertainty
What determines whether harvesting is sustainable?
1. Harvest rates (predation rate) -numerical response (# of hunters) -functional response (how many animals killed/hunter) 2. Compensatory or additive hunting mortality 3. Which ages and sexes harvested? Consider reproductive value, effects on reproduction, genetic effective size, etc... ex. think of elk example. Wolves harvest old elk with low RV, humans harvest adult elk with high RV. elk withstand wolf predation better than human
What are the assumptions of line transect sampling?
1. Objects/animals directly on the line are always detected 2. Objects are detected at their initial location, prior to any movement in response to the observer 3. Distances are measured accurately 4. Transect lines are placed randomly 5. Observation of objects are assumed to be independent 6. There are sufficient samples to estimate the detection function
Harvest of wildlife populations can provide?
1. commercial profit 2. food for subsistence 3. control for invasive/pest species 4. connection to nature and animals
E(C)=pN
Detectability: Conceptual Basis N= abundance C= count statistic p= detection probability
N= C/p
Detectability: Inference
A measure of a state variable or vital rate based on a sample of observations
Estimate
True/False Collecting info on age/sex of individuals, although commonly practiced, is not useful in modeling survival.
False
True/False Distance sampling cannot be used with circular points, only with line transects.
False. **can use point or line transects
True/False A population cannot exhibit chaotic dynamics in the absence of demographic or environmental stochasticity.
False; It is not yet known why chaotic dynamics occur. They occur regardless of stochasticity
We have collected data on pygmy rabbits from an enclosure during 1 week (3 days of trapping) in early fall. Please write out the probability of the following encounter history 101 under the following model: • Mb
P(1-c) *c
Which of the following are the two main sources of error that must be dealt with when monitoring any biological system in time and space? a. geographic variation and detection probability b. geographic variation and partial controllability c. structural uncertainty and environmental stochasticity d. demographic stochasticity and process variation
a. geographic variation and detection probability
Which of the following is a key step in adaptive management that differentiates it from SDM? a. monitoring to learn b. starting with objectives; objective driven science c. model-averaging or the ability to deal with model-selection uncertainty d. using models to evaluate the consequences of different actions. e. the ability to handle competing models and hypotheses
a. monitoring to learn
We have collected data over 3 years on cougar survival. Please write out the probability of the following encounter history 101 under the following model. • Phi(t)p(.)
a.) Cormack- Jolly Seber b.) 101 theta tp
Which of these is NOT an assumption of distance sampling? a. Objects/animals on the line are always detected b. Objects/animals are only counted once c. Distances are measured accurately d. Transect lines are placed randomly with respect to the objects/animals of intersect.
b. objects/animals are only counted once
Which of the following statements about logistic pop. growth rate is TRUE? a. the realized per capita growth rate remains constant until abundance equals k b. the recruitment into the pop. (dN/dt) is maximized at exactly 1/2K c. positive density dependence occurs when population size is very small d. population growth is most positive when N is above K
b. the recruitment into the pop. (dN/dt) is maximized at exactly 1/2K
We talked about a number of methods for estimating survival, which of the following is not a method for estimating survival? a.) CJS models b.) Lincoln Petersen c.) Known-fates d.) Kaplan-Meier Method
b.) Lincoln-Petersen **closed pop. no losses or gains
The Kaplan-Meier model allows for what two generalizations of the binomial survival model? a.) independent observations and known fates b.) Staggered entry and censoring c.) staggered entry and robust design d.) censoring and survival
b.) staggered entry and censoring
Which of the following is NOT assumption of the Lincoln-Petersen model? a. All individuals have same prob of capture b. Pop is closed c. No tag or mark loss d. Individuals must be uniquely marked
d.) individuals must be uniquely marked
cannot be determined from a single data point, how good "on average" an estimate is
bias
Which of the following is FALSE regarding connectivity among populations? a. It will tend to cause populations to have synchronous dynamics even if they are in very different environmental conditions b. in birds and mammals, males tend to disperse further and more often than females c. number of dispersers measured by radiotelemetry will often be greater than the genetically effective dispersers measured by gene flow d. Fst (inbreeding coefficient due to genetic drift) increases with connectivity
d. Fst (inbreeding coefficient due to genetic drift) increases with connectivity
In a Bayesian analysis, your "posterior probability", represents a combo of your prior belief and _____
data
Indices assume equal detectability over ____ and over ___
time; space
If 20 tortoises are monitored for 1 year and 5 of them die, what is the survival rate (S) under the binomial model?
0.75 15/20= 0.75
Assumptions of Point Transect sampling
1. animals or objects directly at the point (r=0) are counted with certainty 2. animals do not move prior to sampling in response to the observer 3. distances are measured accurately 4. points are placed at random with respect to animals or objects 5. observations of animals or objects is independent of one another
Two major assumptions of the binomial model
1. fates of all the n animals are known 2. fates are independent of one another **** main violations to these are that animals may travel in groups, and animals are censored before the end of the study.
What are the two sources of error for measuring/monitoring any biological system in time and space
1. geospatial variation 2. detection probability
A pop. of black footed ferrets has shown an average 35% annual increase in abundance per year over the past 3 years. 1. What is lambda, what is r? 2. How many ferrets would be expected if this growth of 35% was constant for 4 more years (4 time steps) and we started with 20 ferrets? 3. Suppose the average 35% increase occurred as the following actual changes each year: 10%, 60%, 55%, 15% a. show that the arithmetic mean (or average) lambda is 1.35 b. what is lambda(g) (=lambda(s)) c. How many ferrets would you expect after 4 years in this case (part b above)? Is that the same or less or more than what you calculated in question 2?
1. lambda= 1.35 r= 0. 30 r=ln(1.35)= 0.30 2. Nt= N0(lambda)^(T) Nt= 20(1.35)^(4) N4= 66.4 66 individuals 3a.) .10+.60+.55+.15= 1.4/4= .35+1= 1.35 b.) (lambda 1*lambda 2*lambda3* lambda4)^(1/4) =(.10*.60*.55*.15)^(1/4)= 1.33 c.) Nt=N0(lambda)^(T) Nt= 20(1.33)^(4)= 63 individuals; less
Factors that make a species more susceptible to overhunting
1. low pop growth rate 2. preferred species 3. easy to find
MSY depends on
1. number of animals harvested 2. who gets harvested 3. how much the mortality imposed by harvest can be compensated
In an information theoretic approach, the most parsimonious model has what two key attributes?
1. proper fitting model 2. least number of parameters
** Know the 4 different models for detection functions
1. uniform 2. negative exponential 3. half-normal 4. hazard
Name two reasons why an index to abundance may not be appropriate?
1. varies over time and space 2. assume relationship
• Possible encounter histories for a three year study (note: all encounter histories start with 1) Capt. History Probability 111 101 110 100
100 𝜙𝑝𝜙𝑝 101 𝜙 1 − 𝑝 𝜙𝑝 110 𝜙𝑝(1 − 𝜙𝑝) 100 1 − 𝜙 + 𝜙 1 − 𝑝 (1 − 𝜙𝑝)
Complete enumeration of all of the individuals in the population. Detection probability equals 1
Census
True/False Enemy mediated apparent competition describes the situation where herbivore species are considered enemies because they compete for plant food resources.
False; apparent competition occurs when the introduction of a prey species causes the population of a native prey species to decline
True/False If something is biologically significant then it must also be statistically significant.
False; biological significance does not ensure statistical significance. To demonstrate that you need to use a null hypothesis test.
Name one of the two prominent threats to biodiversity.
Habitat fragmentation
Explain what model Mh is and why it is so difficult to estimate/ fit?
Heterogeneity model; difficult because it varies with each animal, and is very data hungry.
Any measure or count of a species based on direct observation (or of sign) that provides some numerical scale of observation
Index
Compare Line transects vs. Point counts for birds
Line - cover larger areas more quickly -have to assign line segments to habitats -speed may vary Point counts -more practical in rough terrain -easier to assign points to a habitat type -fixed time at each station -more time to see or hear birds in high canopy
Compare line transects vs. point counts for marine mammals
Line -cover larger areas more quickly -speed can be standardized -distance estimation when moving may be more difficult Point Counts -fixed time at each station -have to travel to each station -less area covered to see animal/sign -more time at one location to see animal/sign
Encounter probabilities • Encounter history: 𝜔 = 101 M00 Mt0 M0t Mtt
M00 Pr 𝜔 = 𝜙 (1 − 𝑝) 𝜙p Mt0 Pr 𝜔 = 𝜙 (1 − 𝑝2) 𝜙𝑝3 M0t Pr 𝜔 = 𝜙1 (1 − 𝑝) 𝜙2p Mtt Pr 𝜔 = 𝜙1 (1 − 𝑝2) 𝜙2𝑝3
highest number that can be harvested sustainably
MSY
The analytical sensitivity, or amount that lambda changes with an infinitesimal change in a vital rate, depends on the asymptotic stable stage distribution and_______ of the stage class with that vital rate
Reproductive value
True/False Given the preference and logistical feasibility (e.g cost and effort), it is always better to collect CMR data using individual marks as opposed to batch marking?
True
True/False Harvest can be sustainable OR contribute to decline and extinction
True
True/False If mortality due to coyote predation is completely compensatory, coyotes could kill 70% of deer fawns in a population in a year without affecting fawn annual survival. (assume fawn annual survival is <equal to 30%)
True
True/False Small habitat patches support lower diversity than large patches, especially of habitat specialists.
True
Which type of functional response (Type I, II, or III) do we typically ignore because there are very few, if any biological realistic mechanisms that describe such a relationship?
Type I
in CJS models, what do you assume in time 1?
animal is captured in time 1, so don't estimate detection for time 1
In the Cormack- Jolly- Seber model, define what phi is and why it is different than S.
apparent survival; it's different because we don't know if the ones captured have left or died
Which one of the following is FALSE about habitat fragmentation: a. habitat is often suboptimal near the border with another habitat b. small pieces of remaining habitat sustain less diversity than contiguous habitat c. all species move through fragmented habitat at the same rate d. how a species responds to fragmentation depends on the degree of habitat specialization by that species e. habitat fragmentation is different from habitat loss because it changes connectivity
c. all species move through fragmented habitat at the same rate
Which of the following is TRUE regarding study design 4 in Resource Selection functions? a. measurements are made at the population level and availability is made at the population level b. measurements made at the individual level and availability defined for an individual c. habitat use and availability defined for an individual at a given location AND given time d. individual animals identified, availability at population level
c. habitat use and availability defined for an individual at a given location AND given time
Which of the following is NOT a mechanism that leads to positive density dependence? a. minimize predation via predator satiation when density of prey is high b. increased predator detection and defense c. henhouse syndrome d. increased resource detection
c. henhouse syndrome
Which of the following is NOT an approach to test hypotheses: a. null hypothesis tests b. Bayesian inference c. maximum likelihood estimates d. information-theoretic
c. maximum likelihood estimates
Which of these is NOT an assumption of single season occupancy modeling? a.) sites are closed to changes in occupancy state between occasions b.) sites are independent of each other c.) all individuals are uniquely marked d.) species are identified correctly
c.) all individuals are uniquely marked ** not dealing with individuals. Just need to note whether they are present or not
Naive estimates of occupancy will always be lower than those from occupancy models unless the following is true? a. p does not equal 1 b. p>1 c. p=1 d. p<1
c.) p=1 **can't be B, because detection probability can't be over 100%
Which of the following can NOT be modeled using a multi sample closed population model? a.) Trap response b.) individual heterogeneity in capture probability c.) recruitment d.) time effects in capture probability
c.) recruitment
Flying squirrels. Want to estimate population size. Capture, marking, recapturing. Done in winter when not moving much. Which model is best? (Closed captures, CJS, JS, Binomial model, Kaplan-Meier)
closed captures
What does an index to abundance implicitly assume about detection probability?
constant detection
The assignment test is a non-equilibrium genetic tool that measures what?
current gene flow between populations
Your boss wants you to estimate density of pronghorn and proposes that you establish 50 transects in pronghorn habitat and that you traverse each transect looking for pronghorn. What additional piece of info should you collect and what kind of model/estimation technique should then be used?
distance to individuals; distance sampling
difference between two or more treatments
effect size
Briefly describe one main difference between minimum convex polygons and utilization distributions in the context of analyzing home ranges and animal use.
frequency MCP= points along a border UD= frequency within an enclosed area
Inability to carry out a targeted action
partial controllability
You have collected data at 100 sites for the presence /absence of Carolina Madtoms. You visited each of the 100 sites 3 times and have the following detection history at 1 site 110. Please write out the probability of this detection history using the single species occupancy model with constant occupancy and detection probabilities.
pp(1-p)
closeness of repeated measurements to the same quantity
precision
subset of individuals from within a pop. used to estimate characteristics of the whole pop.
sample
Name a factor that can lead to the upper limit of the functional response curve for a predator
satiation
arbitrarily defined spatial unit (forest patch of a specified size) or discrete naturally occurring sampling units (ponds)
site
One of the two main sources of variability when sampling populations
spatial variation
probability of correctly rejecting a false null hypothesis
statistical power
In the iterative phase of AHM, decisions are ALWAYS made under some degree of ____?
uncertainty