1. Counting/Estimating Populations

2. Counting Populations
How do you think scientists calculate the population of wildlife, such as deer, fish, penguins, and other animals?

3. Why is counting a population important?
Knowing the size of a population of animals is extremely important in making environmental decisions that would affect the population, but estimating the size of wild populations is very difficult.

4. Why is counting a population important?
In the case of whales, the task is very challenging. Estimates of the number of Minke whales, for example, have differed by as much as a factor of 10. Deciding whether to allow hunting of Minke whales, based on population estimates that are too high, could lead to extinction of the species. Basing a decision on a low estimate could ban hunting of Minkes by people who rely on them for food.

5. Methods
There are two main methods that we will look at: 1. Mark & Capture (aka catch & release) Scientists catch the animal, mark them, then release them. At a later time, animals are caught from the same population and observe how many are marked. A calculation is used to estimate the population. (Lincoln Index)

6. Methods
2. Line-Transect Survey Scientists will observe every animal seen while traveling in a straight line. This is usually used for land animals but has been recently applied to counting whales.

7. Methods
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8. Methods: Set up a t-chart in your notes like the one below:
Method Pros Cons
line transect
survey
mark & capture