Some of the most common measurements taken in wildlife ecology are abundance, richness, and diversity. Biologists often make management decisions to cause benefit or harm to one or a few particular species. The rationale of this lesson is to teach students these concepts and some of the difficulties in measuring and defining them. This is a content-heavy lesson; more skill-based experiences will follow in the field trips.
Estimated Time of Activity: 1.5 hrs
Students will be able do the following as a result of the activity:
- Know what richness, abundance, and diversity are
- Understand how the above concepts might be measured (abstractly) and calculated (Simpson’s index of diversity)
- Know the biological species concept, and its limitations
1. Students should now realize, after last week, that science has a lot to do with measuring numbers and comparing them. Today we are going to look at 3 common quantities that are measuring in wildlife ecology: abundance, richness, and diversity. The class should start with the powerpoint for this lesson, which attaches this lesson directly to the first class and includes a short activity (lynx/hare discussion) that builds on lesson 2 and 3 (hypothesis formation and graph interpretation). On slide 7, you should begin the Toy Animal Activity (see worksheet and instructions).
2. The toy animals are used to illustrate communities of animals. From these fake communities the students measure richness, abundance, etc. The calculation of Simpson’s index does not need to be memorized or necessarily understood mathematically/probalistically; the point is to show that diversity is a combination of richness and abundance and therefore people have tried to come up with a way to quantify it. Simpson's is just one of many.
3. The powerpoint continues after the toy activity to further discuss what a species is and how it is often difficult to define. This is important in terms of endangered species management and in justifying management decisions. I thought a basic discussion of this is important, but if time is limited or students need extra time for the other subjects, the in-depth slides (animal comparisons, ring species, etc) can be eliminated and just the definition of the BSC given.
The above assignment and toy worksheets
Students should write a page on how the urban environment may differ from a typical forest or meadow (or any other environment) in terms of abundance, richness, species list, and diversity.
- Lots of small toy animals (~15-20 per group) + Toy Animal Activity sheet and Activity Instructions
- Powerpoint (link coming soon)
As said above, individual teachers may wish to discard a lot of the species concept stuff. It is not directly related to the bones of the course, but I think it is worth showing that sometimes managers must wrestle with questions of a population’s uniqueness or importance (e.g., spotted owls, Florida panthers) when there are other populations (of similar or same species) that are doing fine elsewhere. Should funds be spent on conserving these groups?