This activity complements Snapshot Wisconsin, a volunteer-based wildlife monitoring project involving a statewide network of trail cameras. In this activity, students will use the trail camera photos to make observations and ask scientific questions. Students gain experience with the scientific process by making detailed observations and using these observations to pose questions that can be answered by further observations and/or experiments to gain insights into important ecological processes.

Students are first introduced to the practice of making observations and posing questions using a single trail camera photo taken at a unique place and time. Students then make observations based on groups of photos taken at various locations or during different time periods to identify trends across space and time. This lesson plan includes an optional activity that takes students outside to make observations.

The scenario is that the student is working in the engineering department of a manufacturing plant. The plant has access to a wide variety of machining tools, so it is customary for them to make or repair their own parts as things wear out. Many of the parts are unique to the equipment at the facility, so it is impossible to simply order one from some outside supplier. Even if a part was available, it is cost prohibitive to buy new.

Students will be provided with a small piece of machinery that they must reverse engineer the dimensions. For middle school level students, the geometry will be kept rather simple and the measurements straightforward. For high school students, the geometry can become more complex, requiring some drafting skill, caliper use, and higher level CAD design.

Once the students take all the necessary measurements, then using CAD (Tinkercad for the lower grades), they will build up a virtual mock-up of the part. From there, the option would be to teach additive or reductive design. The part could be recreated using either a CNC or 3D printer.

This activity reviews the concept of trophic cascades. Trophic cascades occur when predators reduce the abundance or change the activity of their prey, thereby allowing species in the next trophic level to increase in number. These indirect effects by the predator can trickle down (or cascade) to many lower levels of the food chain. In a classic example, sea otters protect kelp forests, sea otters protect kelp forests by controlling the abundance of urchins that graze upon the kelp. In the absence of otters, urchins consume most of the kelp and negatively affect other organisms that live in the kelp forests.
Trophic cascades have been described in numerous ecosystems ranging from kelp forests of the Pacific Ocean to arctic islands, to Central American jungles, to salt marshes. In this activity student use organism cards to build examples of trophic cascades based in different ecosystems, including several in Wisconsin!

In this lesson, students will learn about the different properties of paper towels and design a method for testing paper towel absorbency and strength.