Tracce di animali: impronte, escrementi, tracce di pasti, borre, tane e nidi

1. What they did

This is a pocket field guide to the tracks and signs of European animals, mostly mammals and birds, in an Italian translation of Angelika Lang’s German book (first published in 1985). The introduction explains that many animals stay hidden from us because they are shy or active only at dusk and night, but they leave signs of their presence and behaviour. Once vital for hunting, reading these signs is still important for hunters and forest wardens, and the author argues that the more people know about wild animals’ habits, the better they can be protected.

The guide has five chapters, each with a general introduction and then species accounts with photographs and drawings on the facing page:

• Footprints (Impronte)
• Droppings (Escrementi)
• Feeding signs (Tracce di pasti), including feathers
• Pellets (Borre) of owls and other birds
• Burrows, dens and nests (Tane e nidi), including tree holes, resting places and open nests

It also explains how measurements are taken, gives a glossary and an index.

2. What they found

How to measure and read a print

• Measurements always refer to fresh prints.
• Hoof width is measured across the widest part of the sole; length from the tip of the sole to the back of the heel, without the dewclaws unless stated.
• Paw width is the distance between the outer edges of the two outer toe pads; length runs from the front of the foremost toe pads to the back of the main (digitigrade) or wrist (plantigrade) pad, claws excluded.
• In melting snow, mud and after rain, print edges dissolve and prints look bigger and less clear. In deep powder snow, edges can be wiped out as snow slides in. On hard ground not every part of the foot registers, so the print looks smaller.
• In the drawings, front feet are shown in white and hind feet in black.

Footprints and gaits

• Mammals are grouped by how they stand: plantigrade, digitigrade and unguligrade. The shape and layout of the pads is typical of each species. How far the two hoof halves spread, and whether dewclaws show, are key to identifying hoofed animals.
• At a walk the hind feet land more or less on the front prints, forming two parallel rows; at a trot the stride lengthens and the trail narrows; at a gallop the hind feet land well ahead of the front feet.
• Species accounts give print sizes and stride lengths, for example adult male moose prints about 13 to 16 cm long, red deer front hooves 7.5 to 9.5 cm long, and fallow deer separated from red deer by the toe pads covering half rather than a third of the hoof.

Droppings, feeding signs, pellets and homes

• Droppings change with diet and season (for example, soft summer and hard winter droppings in moose and red deer) and with weather: rain makes them swell, strong sun dries and shrinks them and leaves a grey to whitish crust.
• Feeding signs on bark, nuts, cones and fruit can be told apart by tooth-mark width and gnawing technique. A young red squirrel gnaws all over a hazelnut, while an experienced adult cuts one groove and splits the shell in two; edible dormouse tooth marks are 5 to 6 mm wide. Birds leave beak marks instead of tooth marks.
• Pellets of owls and birds of prey are described by size, shape, content and where they are found (under perches, near nests).
• Burrows, dens, tree holes, resting places and nests are described with entrance sizes, depths and heights, for example great spotted woodpecker holes 3 to 8 m up with a round entrance of 4.5 to 6 cm.

3. What they concluded

• Those who can find and interpret tracks and signs learn many animal behaviours and can take animals’ needs into account more easily than someone who wanders through woods and fields “like a blind person”.
• Woodpeckers make nesting holes available to many other species (small birds, stock doves, owls, bats and dormice). The book regrets that forestry removes old rotten trees, and notes that nest boxes can partly make up for the shortage.

4. How tracking was or was not used

The whole book is about tracks and signs identification: footprints and trails in different gaits and substrates (including snow), droppings, feeding signs, feathers, pellets, burrows, beds and nests. It does not describe trailing.

6. Other technologies, skills or innovations

• Paired photographs and drawings for each species, with numbers in the text matching the figures on the facing page.
• Drawings of trails showing the front feet in white and the hind feet in black.

7. Implications for conservation (from the paper)

• With refuges for rarer wildlife disappearing and recreational pressure on natural areas growing, the author argues it is essential that as many people as possible know wild animals’ habits, and that reading tracks and signs is a way to learn them.
• Forestry that removes old, rotting trees works against animals that live in tree holes; nest boxes can partly ease the shortage.