Hello Everybody,
I received a bunch of questions a while ago. There were so
many good questions that I had a hard time picking where to start. We are going
to start off with an easy, but interesting question. Then we will work our way
through what scientists might be able to learn about your outdoor classroom and
the techniques they might use.
Student Question: How do people gather animal tracks?
There are many different ways to gather information about
animal tracks! Scientists can take images or make casts of tracks that they find,
but they can also use print traps to collect animal tracks.
I have taken pictures of tracks that I have found when I’m
out hiking or fishing.
I took this picture when I was fishing at Mark Twain Lake,
but can anybody point out what I did wrong? I didn’t take a very scientific
photo.
If you haven’t already guessed, I left out a scale! I don’t
have anything in the photo that would tell me or anybody looking at it – just
how big are these tracks? These tracks could be GIANT or really small. So
remember, when you take pictures of stuff like tracks or scat, make sure to
include a ruler or some other type of scale! Thankfully, I remember that these
tracks were about 6-9cm long. If we zoom
in, maybe we can figure out what kind of animal had been walking along the
lake.
Let’s look at some of these prints and compare. If you visit
the Missouri Department of Conservation website,
they have examples of many different animal tracks that you might find out on a
hike.
Step 1: What kind of animals do you think you might find
alongside a lake in Missouri? Most of the animals listed by the MDC would
probably go to a lake to drink, so that doesn’t narrow it down a lot, but we
can probably cross animals like polar bears and koalas off the list.
Step 2: What kinds of animals, in Missouri, are going to
have feet that are around 6-9cm long with more than two toes? Deer have hooves
and not more than two toes. Rabbits and squirrels will be too small. It sounds
like opossums, foxes, skunks, and raccoons might be the right size!
Step 3: Compare your short list of animals.
Figure 1 Track Images from Missouri Department of Conservation Website
Now, which animal do you think made the tracks in my
picture? Here is a video that might help!
Did you say “Raccoon!”? If so, then Congratulations! You are
correct!
You have done the same thing that scientists do when they
are trying to identify tracks. Sometimes the scientists will want to find out
what animals are living in an area. They can use things like sand track traps.
The scientists use bait (an interesting smell) to attract animals to a smooth
area of sand. Then they take pictures of the tracks in the sand. Students at
another school have used this method in the past to research animals in their
outdoor classroom. Click here
to read their science poster that talks about what they did.
Have you ever seen a scientist make a plaster cast of an
animal track? Even more detailed than a picture, a plaster cast of a track lets
a scientist take the track with them back to the lab. Here is a great video
that describes how to make a plaster cast! This is a neat technique that works for both scientists and people that want to make a nature collection.
Another method that scientists might use is a track plate.
These use some type of pigment or ink on an animal’s foot to mark a piece of
paper. They use bait, like chicken or fish, to lure the animals into walking
over soot or graphite and then onto paper. The paper records the animal’s
tracks.
Figures 2 and 3 Images taken from http://www.hrcllc.com/archives/tracking-rare-mammals-on-mrc-lands/
Using these methods, scientists know what types of animals
are present in the habitats that they study. The techniques tend to use easy to
make and use equipment, provide good results, and are safe for animals who
encounter them. Unfortunately, they don’t work for all animals. Many larger
animals are difficult to entice over small track plates. Using track plates,
along with other methods like human observation and wildlife cameras, will
still give you the best results.
Sources:
http://mdc.mo.gov/discover-nature/common-plants-and-animals/mammals/mammal-tracks
http://www.hrcllc.com/archives/tracking-rare-mammals-on-mrc-lands/
