In this article we invite you to follow the clues left by some mammals; but not just any kind of clues, but very particular ones, their tracks. By doing this activity you will be able to observe and identify different types of tracks, learn how to gather information about an animal track, and analyze the information obtained to draw some conclusions. conclusions.
Not all the detectives we know are dedicated to investigating people, there is a certain type that is in charge of investigating animals. Within the community of biologists there is a group that works like the detectives in the movies, looking for tracks and clues to the presence of an animal.
These detectives know that most mammals are only active at night, so we hardly ever see them during the day. Despite this, we can learn a lot about them from the clues they leave behind, such as footprints or food scraps.
What is a mammal?
Mammals are vertebrate animals that are characterized by having mammary glands with which they suckle their young. They generally have hair, which can be all over the body or only in some parts. They maintain a constant internal body temperature, often higher than that of their environment, which allows them to remain active in cold conditions. They are mostly viviparous.
Introduction to the study of tracks
Tracks are one of the most informative clues in terms of the activities carried out by animals since, for example, they allow us to know where they are going, whether they walk in groups or alone, and so on. On our planet there are about 4,000 species of mammals living in the most diverse habitats. We can often know of their presence in an area by the tracks or other signs they leave behind.
In order to deepen our knowledge of mammals, different methodologies have been developed based on both direct and indirect observation. The observation of tracks is an indirect method to know and study the diversity of mammals that exist in an area and the activities they carry out. The tracks of the different types of mammals present very particular characteristics that allow us to identify them with relative ease.
The importance of the land
The type of terrain is an important factor in identifying an animal's footprints. On stony ground or with vegetation on the ground, for example, it is practically impossible to find tracks; on the other hand, dirt roads and footpaths are suitable for footprints to be marked. An excellent place to find small animal tracks are the ditches formed by the passage of water on both sides of the roads. The banks of streams, rivers or lakes are also good terrain, and the finer the sand, the more detailed the tracks will be.
Finding a track allows us to identify the presence of an animal at a given site, however, it is important to obtain as much information as possible about this organism. For this reason, it is necessary to keep in mind various aspects of the biology of animals such as their general distribution, habitat, feeding habits, hours of activity, habits, etcetera.
Tracks are clearly observed and identified when they are seen in the same direction in which the animal moved. The best time to look for tracks is in the morning, when there is sufficient light. When checking an area it is useful to make a prior list of the animals that are likely to inhabit it.
Methods for the collection of footprints
The best method for the collection of footprints is the elaboration of plaster casts. The material needed to make them is as follows:
a plastic container
a spoon or stirring paddle
When you find a track it is convenient to mark it and look around looking for another one that could be in better conditions. Once the footprint has been chosen, it should be carefully cleaned by removing small branches or debris that may have fallen on it. Before preparing the plaster it is convenient to write down the most important data about the footprint found, which are provided later in this article.
How is gypsum prepared?
The mixture is prepared with approximately two parts of plaster to one part of water. It is important that it is not too watery (because it could run off and take a long time to dry) or too thick (because it would not capture the small details of the print). The mixture should be poured slowly and carefully over the print, from a low height, making sure that it covers it completely and that the layer formed is thick to prevent the mold from breaking when it is handled later.
When the plaster is dry (a good indicator of this is when passing the fingers over it, they do not stain) it will be lifted by introducing a knife around and below it to loosen the soil, with which it will come out easily. Excessive soil is removed, wrapped in paper and stored in a plastic bag. Later it will be washed with running water and a small brush.
It is very important to wrap the molds in newspaper or sanitary paper so that it absorbs humidity and protects them from possible blows. If the molds are stored in plastic bags without being covered with an absorbent material, they will soften and become very brittle. If desired, while the mold is hardening, some notes can be made on it.
Let's learn to identify footprints
Each mammal leaves very particular tracks in terms of shape and size, so that by comparing the samples collected with reference schemes and considering the measurements obtained, it is possible to identify the animal that produced them. However, it is not always easy to make the correct identification. From the general pattern of the footprint of each species, variations may occur due to various factors such as the type of soil, the type of gait, the characteristics of the terrain, the passage of time, and so on.
The following is a list of data that should be noted when a footprint is found:
width of track
length of the track (do not include claw marks)
You are now encouraged to become detectives and go out to look for the tracks of various mammals that live in your community. With this activity you can learn a lot about the way these animals live and also have a great time.
Authors: Alejandra Alvarado Zink and Citlalli Álvarez Saulés, Source: Correo del Maestro, No. 32.