/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 62 One implicit assumption when usi... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

One implicit assumption when using the capture-recapture method to estimate the size of a population is that the capture process is truly random, with all individuals having the same likelihood of being captured. Sometimes that is not true, and some populations have a large number of individuals that are "trap-happy" individuals (more prone to capture than others, more likely to take the bait, less cagey, slower, dumber, etc.). If that were the case, would the capture-recapture method be likely to underestimate or overestimate the size of the population? Explain your answer.

Short Answer

Expert verified
The presence of 'trap-happy' individuals in a population would likely lead the capture-recapture method to overestimate the size of the population.

Step by step solution

01

Understand the Capture-Recapture Method

The capture-recapture method involves capturing a number of individuals from a population, marking them, and then releasing them back into the population. After some time, a second sample is captured, and the number of marked individuals within this second sample is used to estimate the total population size. The key assumption is that each individual has an equal chance of being captured in both the first and the second sample.
02

Assess the Impact of 'Trap-Happy' Individuals

'Trap-happy' individuals have a higher likelihood of being captured compared to other members of the population. If the proportion of these individuals is significant, they would be overrepresented in both the initial capture and the recapture samples.
03

Determine the Effect on Population Estimate

Because 'trap-happy' individuals are more likely to be captured, they would skew the ratio of marked to unmarked individuals in the second sample. This could lead to an overestimation of the overall population, as the method would incorrectly infer that a larger population is needed to account for the higher number of marked recaptures.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Population Estimation
Population estimation is a crucial process in ecological studies and wildlife management. The capture-recapture method is a commonly used technique for estimating the size of a population, particularly when it's impractical to count every individual, such as in fish or wildlife populations. In essence, it's based on a proportion: if we know how many individuals we've tagged in a sample and then later see what fraction of these tagged individuals appear in a new sample, we can estimate the total population. To illustrate, let's say we capture and tag 50 fish in a lake, release them, and then capture another 100 fish a few days later, of which 10 are tagged. Using the ratio of tagged to untagged fish in the second catch, we estimate the lake's fish population.
It's critical to note that this method assumes a closed population (no immigration, emigration, births, or deaths) and that marked individuals mix thoroughly and randomly with the unmarked ones. These assumptions must hold true for the estimation to be accurate. When considering improvements to the exercise, emphasizing the importance of a large enough initial sample and the thorough mixing of tagged individuals would help clarify the methodology and potential sources of error.
Sampling Bias
Sampling bias occurs when the sample is not representative of the entire population, leading to distorted findings. In the case of the capture-recapture method, if certain individuals are more prone to capture ('trap-happy'), the method's assumption of equal capture probability for all individuals is violated. This type of bias can dramatically affect the accuracy of the population estimation.
For students to fully grasp the concept, it's beneficial to explore examples of sampling bias outside of the capture-recapture context. For instance, a survey based on social media may inherently exclude demographics with limited internet access, thus skewing results. By drawing parallels with such examples, students can better understand the significance of reducing bias and designing studies that ensure as random a sampling process as possible.
Ecological Statistics
Ecological statistics involve applying statistical methods to ecological data, helping scientists make sense of complex biological patterns. For students studying the capture-recapture method, an introduction to the basic principles of ecological statistics can reinforce the importance of statistical reasoning in studying ecosystems. Engaging with concepts like variance, confidence intervals, and hypothesis testing can provide insight into the reliability of population estimates and the factors that may affect such estimations.
Introducing real-life ecological dilemmas, such as estimating the number of a threatened animal species, could contextualize the relevance of statistical methods in conservation efforts. Understanding the role statistics plays in informing environmental policy and management decisions demystifies the process and the figures that often inform public discourse.
Research Methodology
Research methodology is the backbone of scientific inquiry, providing the framework for collecting, analyzing, and interpreting data in a systematic, reproducible manner. In ecological studies, the capture-recapture method is part of this broader research methodology. Teaching students about the rigorous processes involved in designing studies, which incorporate the scientific method and ethical considerations, is fundamental.
When discussing improvements in exercises, introducing the ethical dimensions of handling wildlife, ensuring minimal stress and harm, and obtaining necessary permissions could expand the student's perspective. Encouraging critical thinking about the limitations and potential improvements of each study design helps build a comprehensive understanding of research methodologies. Students should also be familiar with the importance of peer review and reproducibility in establishing the validity of research findings.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Refer to the following story: The city of Cleansburg has 8325 registered voters. There is an election for mayor of Cleansburg, and there are three candidates for the position: Smith, Jones, and Brown. The day before the election a tele. phone poll of 680 randomly chosen registered voters produced the following results: 306 people surveyed indicated that they would vote for Smith, 272 indicated that they would vote for Jones and I02 indicated that they would vote for Brown. 17\. (a) Describe the population for this survey. (b) Describe the sample for this survey. (c) Name the sampling method used for this survey.

Today, most consumer marketing surveys are conducted by telephone. In selecting a sample of households that are representative of all the households in a given geographical area, the two basic techniques used are (1) randomly selecting telephone numbers to call from the local telephone directory or directories and (2) using a computer to randomly generate seven-digit numbers to try that are compatible with the local phone numbers. (a) Briefly discuss the advantages and disadvantages of each technique. In your opinion, which of the two will produce the more reliable data? Explain. (b) Suppose that you are trying to market burglar alarms in New York City. Which of the two techniques for selecting the sample would you use? Explain your reasons.

Refer to the following story: An orange grow. er wishes to compute the average yield from his orchard. The orchard contains three varieties of trees: \(50 \%\) of his trees are of variety \(A, 25 \%\) of variety \(B,\) and \(25 \%\) of variety \(C\) (a) Suppose that the grower samples randomly from 300 trees of variety A, 150 trees of variety \(B\), and 150 trees of variety C. What type of sampling is being used? (b) Suppose that the grower selects for his sample a 10 by 30 rectangular block of 300 trees of variety \(A\), a 10 by 15 rectangular block of 150 trees of variety \(B\), and a 10 by 15 rectangular block of 150 trees of variety \(\mathrm{C}\). What type of sampling is being used?

(a) For the capture-recapture method to give a reasonable estimate of \(N\), what assumptions about the two samples must be true? (b) Give reasons why the assumptions in (a) may not hold true in many situations.

The critically endangered Maui's dolphin is currently restricted to a relatively small stretch of coastline along the west coast of New Zealand's North Island. The dolphins are "captured" by just collecting samples of DNA and "tagged" by identifying their DNA fingerprint. A 2010 2011 capture- recapture study "captured" and "tagged" 26 Maui's dolphins in \(2010 .\) In 2011,27 Maui's dolphins were "recaptured" and through their DNA, 12 were identified as having been "tagged" in 2010. Based on these figures, estimate the population of Maui's dolphins in 2011. [Source: Oremus, \(\mathbf{M}_{\cdot,}\) et al, "Distribution, group characteristics and movements of the critically endangered Maui's Dolphin (Cephalorhynchus hectori maui)." Endangered Species Research, preprint.]

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.