5.5.2 Estimating Population Size

• What is the definition of a population in ecological terms?

  All individuals of a species
• Population density refers to the number of individuals per unit area.
• A population can be formally defined using the notation $P =$${x_{1}, x_{2}, ..., x_{n}}$, where $x_{i}$ represents individual members
• What are the two main areas for which estimating population size is crucial?

  Management and conservation
• Give an example of how estimating population size is used in conservation.

  Monitoring polar bear populations
• Population boundaries define the geographical limits of the group being studied.
• Population density measures the number of individuals per unit area
• Steps to manage fish stocks sustainably using population estimates:

  1️⃣ Estimate fish population size

  2️⃣ Set fishing quotas

  3️⃣ Monitor population health

  4️⃣ Adjust quotas as needed
• What are the two primary methods for estimating population size?

  Quadrat sampling and mark-recapture
• Quadrat sampling involves counting individuals within small, defined areas called quadrats
• What formula is commonly used in the mark-recapture method to estimate population size?

  Lincoln-Petersen Index
• The mark-recapture method assumes that there is no mortality or migration between captures.
• Match the method with its key assumption:

  Quadrat Sampling ↔️ Uniform distribution of species

  Mark-Recapture ↔️ No mortality or migration
• What is the Lincoln-Petersen Index used to estimate in ecological studies?

  Population size
• The mark-recapture method is suitable for populations that are mobile
• What is one disadvantage of the mark-recapture method?

  Assumes no population change
• What is the formula for the Lincoln-Petersen Index?

  $N =$$\frac{M \times C}{R}$
• In the Lincoln-Petersen Index, $M$ represents the number of marked individuals released
• One assumption of the Lincoln-Petersen Index is that there is no mortality or migration between captures.
• What is another assumption of the Lincoln-Petersen Index regarding marks?

  Marks don't affect behavior
• The Lincoln-Petersen Index assumes that all individuals have an equal chance of being recaptured
• Why is the Lincoln-Petersen Index suitable for mobile populations?

  Allows movement between captures
• The Lincoln-Petersen Index assumes that the population size changes between captures.

  False
• The Lincoln-Petersen Index requires careful marking techniques to ensure accuracy.
• What defines a population in ecological terms?

  Individuals of a species in a defined area
• Population density measures the number of individuals per unit area.
• What does population density measure?

  Individuals per unit area
• A population $P$ can be formally defined as a set of individual members $x_{i}$ represented by $P =$${x_{1}, x_{2}, ..., x_{n}}$
• Estimating population size is essential for both management and conservation purposes.
• What is the primary goal of population management?

  Balance resource use
• Monitoring population health is a key benefit of estimating population size for disease control
• What is an example of using population estimates for conservation?

  Monitoring polar bear populations
• What are the two primary methods for estimating population size?

  Quadrat sampling and mark-recapture
• Quadrat sampling is effective for mobile organisms.

  False
• The mark-recapture method uses the ratio of marked to unmarked individuals to estimate the total population size
• Which method assumes that marks do not affect behavior?

  Mark-recapture
• What is a quadrat in quadrat sampling?

  Small, defined area
• In quadrat sampling, density is calculated by dividing the number of individuals by the area of the quadrat
• Quadrat sampling is highly accurate for clustered populations.

  False
• What is the primary purpose of the point-count method?

  Estimate bird populations