Manual de huellas de algunos mamíferos terrestres de Colombia

1. What they did

The authors wrote a Spanish-language field guide to the tracks of 33 wild mammal species in Colombia, for professionals, researchers, students, amateur naturalists and the general public. They note that books on neotropical mammal tracks are scarce and hard to find. This copy is a field course edition used for training in tracking for biodiversity monitoring.

The guide opens with how mammal feet are built (plantigrade, digitigrade and unguligrade), what affects the quality of a track, where to look for tracks, and how to record and preserve them. Each species then has a two-page account with:

• Scientific, Spanish and English names.
• A description of the animal, its habitat and ecology (diet, activity and social habits).
• A distribution map and elevation range in Colombia, with CITES and IUCN status.
• A skull drawing and dental formula, and the animal’s size compared with a 1.70 m person.
• Drawings of the front and hind tracks with measurements, and the stride and trail width.
• Body weight and measurements, and similar species that could be confused with it.

It ends with tracks of domestic and introduced animals, a bibliography and eight colour plates.

2. What they found

• Tracks are often seen more than the mammals themselves, because many are discreet and active at dusk or at night. A track may be the only sign that a species is in an area.
• Track quality depends on the animal (species, sex, age, gait and which foot) and on outside factors (weather, ground, substrate and how long ago the track was made).
• Track shape can show how an animal lives: the webbed feet of the neotropical otter and the water opossum show they swim.
• Front and hind tracks differ in most mammals, and the front feet are usually a little smaller.
• Tracks are easiest to find on riverbanks, beaches near vegetation, marsh edges and paths after rain, and on bare, not too wet clay soils. Clear tracks are hard to find in some forests.
• Tracks can be traced on acetate sheets with a fine marker, or cast in plaster (slow to dry) or paraffin (quick but fragile). Track traps can be made from a thin layer of talc, fine sand or crushed stone, kept out of the rain.
• Track counts can give abundance indices that are often simpler and cheaper than counts based on sightings or captures. A drawback is that tracks can build up over a long period, during which numbers may change.
• Combining tracks with skulls, bones, scats and hair gives a more reliable picture of which mammals live in an area.

3. What they concluded

• Correctly read, wild animal tracks are a basic field tool and a non-invasive way to study mammals, which matters as habitats shrink and more species are threatened.
• The guide is meant to help identify wild mammals in the field during ecological studies and fauna surveys, and to build interest in knowing and conserving Colombia’s mammals.
• Tracking can also be used in environmental education, for students, tourists and visitors.

4. How tracking was or was not used

The whole guide is about tracks and signs identification. The track drawings were based on field observations, the authors’ own records and museum skins, then compared with other track guides. The course introduction notes that tracking errors from wrong identification are often high, which is why tracking skills have often been questioned.

6. Other technologies, skills or innovations

• Recording tracks on projector acetate sheets, and casting them in plaster or paraffin, with counter-moulds made from the casts.
• Track traps with talc, sand or crushed stone, kymograph paper, or aluminium foil coated with talc and a silicone waterproofing solution.
• Camera traps are mentioned as another non-invasive method that combines well with tracking.

7. Implications for conservation (from the paper)

• Tracking is a non-invasive way to learn about species’ ecology without harming them, and with camera traps can show whether management measures in an area have helped conserve biodiversity.
• Each species account gives CITES and IUCN status, to raise awareness of threatened mammals.