Identifying tracks is a proxy for the small mammal activity in a given area. Such data can allow students to compare tracks in different habitats, compare tracks over seasons, or get a proxy of small mammal diversity.
- Acetate sheets (or roll of acetate)
- Aluminum flashing (or other hard backing for the acetate, like a clipboard)
- Graphite powder (purchase at an art supply store)
- Ethyl alcohol
- Mineral oil
- Track ID guides. See 42explore.com/animaltracks.htm and www.princeton.edu/~oa/nature/tracking.shtml
- Optional - bait (sunflower seeds work well – don’t use anything with too strong of an odor, like peanut butter)
Constructing track plates: While there are several methods for constructing track plates, acetate sheets with a graphite, alcohol, and oil coating have a superior water-resistance.
- Mix a suspension of graphite powder (art supply) in an ethyl alcohol and mineral oil mixture (80% alcohol, 15% powdered graphite, and 2.5%light-grade mineral oil by volume).300 mL is sufficient for several uses: 240 mL alcohol, 45 mL graphite powder, 7.5 m: mineral oil. If you do not have metric measures, 1 cup of mix is roughly: ¾ cup alcohol, 2 tablespoons graphite powder, 1 teaspoon oil.
- Apply mixture to acetate sheets with a foam paintbrush. It will be a light gray color. Let dry (1-2 minutes)
- Affix track plates with paper clips to pieces of aluminum flashing to provide rigid backing.
- Place track plates along transects, or randomly in differing habitats.
- Place small amount of bait in the middle of the track plate. Consider the bias inherent in baiting (aversion or attraction of certain animals, may not be appropriate) and determine whether this bias will interfere with your investigation.
- Leave out for 24-36 hours (best when rain is not predicted, though this mix is waterproof)
- Identify the tracks