Pug Marks

The word ‘Pug’ originates from the Hindi language meaning ‘foot’. Pug marks refer to the footprints left by animals on the ground, typically in soft soil or mud. These footprints can provide valuable information about the species, individual characteristics, and behaviour of the animal.

WHY IS IT IMPORTANT TO STUDY PUG MARKS?

The examination of pug marks, also known as pugmark tracking or pugmark analysis, is a traditional method used in wildlife forensics and animal tracking to identify and study individual animals based on the unique characteristics of their footprints. This technique is particularly common in the tracking of large mammals, such as tigers, leopards, and other wildlife species.

Pug mark analysis is a non-intrusive method of monitoring wildlife. It allows researchers to gather information about animals without direct interaction, reducing the stress on the studied individuals.

There are a number of reasons why the study of pug marks holds significant importance in the realm of wildlife conservation and ecological research. Below, we delve into 6 key points highlighting the critical aspects that make the examination of pug marks an indispensable tool in wildlife forensics.

Identification of Species: Different species have distinct footprints, and investigators can often identify the species based on the size, shape, and features of the pug marks. This is particularly useful in tracking and monitoring wildlife populations.
Individual Identification: In some cases, individual animals within a species may have unique characteristics in their footprints. Pug mark analysis can be used to identify and track specific individuals, which is valuable for conservation efforts and wildlife management.
Population insights: Pug marks are an indirect indication of animal presence in particular area. The information ontained from pugmark analysis helps in building databases of animals and contributes to the overall understanding of population size and other dynamics.
Behavioural Insights: Pug mark analysis can provide insights into the behaviour of animals, such as their movement patterns, preferred habitats, and activity periods. This information is valuable for wildlife management and conservation planning.
Conservation Monitoring: Monitoring pug marks over time can help assess the health and status of wildlife populations. Changes in population size, distribution, or behaviour can be indicators of ecological changes or potential threats.
Tracking Endangered Species: Pug mark analysis is often employed in tracking and monitoring endangered species like tigers and elephants, which are often the focus of conservation efforts.

WHAT INFORMATION CAN PUG MARK ANALYSIS PROVIDE?

Identification of Family
Pugmark analysis can assist in determining the family of an animal based on certain evident and distinguishing features in the pug marks that are specific to a particular family. For example: Differentiating between the Canidae and Felidae families.

*Figure: Difference between Canidae (dog family) and Felidae (cat family) pug marks*

a) Felidae (Cat Family): Felids have retractable claws, so their claw marks are usually not visible in the pug marks. They exhibit more rounded, asymmetrical, and compact impressions, as the retractable claws are usually sheathed during walking. For example: Lion (Panthera leo), Tiger (Panthera tigris), Cheetah (Acinonyx jubatus), and Snow Leopard (Panthera uncia).

b) Canidae (Dog Family): Canids typically have non-retractable claws, which means that their claw marks may be visible in the pug marks. They exhibit more elongated, symmetrical, and oval-shaped impressions. For example: Gray Wolf (Canis lupus), Red Fox (Vulpes vulpes), Coyote (Canis latrans), and Arctic Fox (Vulpes lagopus).

2. Ecomorphology

Ecomorphology is a field of study that explores how the morphology of an organism is adapted to its ecological role or habitat. Pug marks can assist in differentiating between morphological features that are functionally related to an animal's behaviour or ecological niches, such as distinguishing between diggers and climbers.

a) Diggers: Animals adapted for digging usually have shorter, more compact digits that are close together. This arrangement helps in creating a more effective digging structure. For example: European Rabbit (Oryctolagus cuniculus), European Mole (Talpa europaea), Groundhog (Marmota monax), and Naked Mole Rat (Heterocephalus glaber).

b) Climbers: Climbing animals often have digits that are more elongated and can be more spread out. This adaptation provides better grip and stability on various surfaces. For example: Eastern Gray Squirrel (Sciurus carolinensis), Raccoon (Procyon lotor), and Koala (Phascolarctos cinereus).

3. Characteristics of Locomotion

Animals can be classified into three categories (plantigrade, digitigrade, and unguligrade) based on adaptations to different modes of locomotion and the structure of the limbs.

a) Plantigrade: Animals with plantigrade limbs walk with their entire foot. The entire sole of the foot, including the metatarsals and phalanges, makes contact with the ground during locomotion. The pug marks are relatively flat and a complete impression of the foot can be observed. For Example: Humans (Homo sapiens) and bears (Ursidae).

b) Digitigrade: Only the digits (phalanges) make contact with the ground during locomotion, while the rest of the limb is elevated. For Example: Wolves (Canis lupus), lions (Panthera leo), and cats (Felis catus).

c) Unguligrade: Only the tips of the digits (hooves) make contact with the ground, with the rest of the limb elevated. For Example: Horses (Equus caballus) and deers (Cervidae).

4. Number of Feet

Pug marks can provide valuable information about the number of feet an animal has, helping to identify whether it is bipedal (walking on two feet) or quadrupedal (walking on four feet).

5. Size of an animal

Pug marks can provide valuable information about the size of an animal, and skilled trackers often use the following features for estimation:

a) Size of the Prints: The overall size of the prints is a key indicator. Larger pug marks generally suggest a larger animal, while smaller prints indicate a smaller individual.

b) Length and Width of the Stride: The length and width of the stride (the distance between successive prints) can provide insights into the animal's size. Longer strides often correlate with larger animals.

c) Depth of Impressions: The depth of the prints can be indicative of an animal's weight. Larger and heavier animals typically leave deeper impressions in the substrate.

6. Speed of an animal

The measurement of stride from pug marks can provide valuable insights into the speed and activity (walking, running, or being chased) of animals. Stride refers to the distance between successive imprints of the same pair of limbs, either hind legs or front legs.

Fast-walking animals cover more ground with each step, resulting in longer stride lengths as compared to slow-walking animals. Stride length can vary among species, making it a useful parameter for identifying and tracking animals in their natural habitats or during forensic investigations.

The steps involved in stride measurement are:

Identify a Clear Set of Prints: Choose a series of consecutive and well-defined prints in the trackway.
Select Starting and Ending Points: Choose a starting point and an ending point that represent one complete stride. Example: from the back of the left hind leg print to the back of the next left hind leg print in the same set of tracks.
Measure the Distance: Use a measuring tape to determine the linear distance between the chosen starting and ending points.

7. Direction of walking

Pug marks can often exhibit certain characteristics that can help in determining the direction of movement. Some features to consider are:

a) Toe Orientation: The front of the toes generally points in the direction of travel.

b) Straddle: Straddle refers to the width between the left and right sets of paws. The direction of movement is generally toward the narrower side of the straddle.

8. Presence of Injuries

Wildlife trackers and experts may analyze pug marks to look for variations in the typical structure and alignment of the footprints that could indicate the presence of injuries or abnormalities. Some typical signs include:

a) Limping or Uneven Impressions: An animal with a limp or injury may leave uneven or irregular impressions in its pug marks. The depth and shape of the prints may vary between the injured and healthy limbs.

b) Altered Stride Length and Pattern: Injured animals may exhibit changes in their normal stride length, pattern, or gait. These alterations can be reflected in the spacing and arrangement of the footprints.

c) Blood Stains or Swelling: In extreme cases, visible signs of injury such as blood stains on the ground or swelling in the paws might be observable in the pug marks.

d) Dragging or Scuffing Marks: Animals with injuries may experience difficulty in walking, leading to dragging or scuffing of the injured limb.

e) Deformities in Print Shape: Injuries or abnormalities in the structure of an animal's foot may lead to alterations in the shape of the pug marks.