1. Terms: population, density, census, sample, index, bias, sampling error, CPUE

Question

1. Terms: population, density, census, sample, index, bias, sampling error, CPUE, accuracy, precision, stratified random sampling

2. Why estimate population sizes? What is required to do it?

3. Give examples of total (complete) counts. What are the advantages/disadvantages?

4. What are sample (incomplete) counts? What are the advantages/disadvantages?

5. How does animal distribution influence your sampling / experimental design strategy?

6. Compare and contrast finite vs. infinite width transects. What is King’s formula used for?

7. Given some scenario, you describe and justify the best method for estimating the size of a target population.

8. Give examples of indirect counts to estimate population sizes. Discuss the pellet group method. What does relative density refer to?

9. Be able to use the Lincoln-Peterson and Schnabel methods. What are the assumptions and consequences of violating them? Know the equation for the L-P method and how to use it. Other equations for variance will be provided if needed.

10. What is the depletion technique for estimating population sizes? Explain how this regression approach works. For what animals does this technique work best? What are the assumptions and how does it work?

11. What is ANOVA and regression analysis used for? How do you make inferences about a population from a statistical test? What is R?

Explanation / Answer

1. Terms:

Catch per unit effort was modeled as: Probability of success = 1 S(t) = 1 exp((tex )1/ ) ,

where t is time, the values of the covariates are contained in the vector x, the regression coefficients are contained in the vector , and is a shape parameter (Allison 1995).

2. The population size is estimated to study the population. The data generated from the study enable scientists to model the fluctuations of a population over time.

The general approaches to estimate the population size involves:

a. total counts ( complete count of every member of a population)

b.incomplete counts (counting part of a population and then extrapolating to the entire population-quadrat method for estimating sessile samples)

c. indirect counts (indirect signs of the animals present as indices of relative abundance)

d. Mark-recapture methods- This methods is used extensively to estimate populations of fish, game animals, and many non-game animals. The method involves capturing a number of animals, marking them, releasing them back into the population, and then determining the ratio of marked to unmarked animals in the population. The population is estimated by the formula:

N= (Total animals marked in the first sample X Total animals captured in second catch)/Number of marked animals recaptured.

3. Total count: Enables estimation of population of large species in open areas, such as waterfowl on lakes, seals on breeding beaches, pronghorns on shortgrass prairiees, deer in enclosed populations etc .

Advantages: accurate estimate

Disadvantages: mammoth approach incurring huge expense and human resource, disturbs the habitat.

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