Many animals very sensibly stay out of the way of humans, if at all possible, some even adopting nocturnal lifestyles to help avoid us. This means that when we are out on surveys, we don’t always get to see the actual animal we are looking to record in the flesh. What we can look for, though, are other signs that a species is using a site, even when the animal in question is lying low. And footprints can be a particularly useful sign. Like detective clues, they let us into a secret world, revealing the species we share our lives with but don’t see. You just need to know what to look for.
Significant Surfaces
We all know from seeing our own footprints in sand or snow that animals will, sadly, only leave a print on relatively soft surfaces. This means that you won’t find prints on concrete, rock and other hard mediums. The only exceptions are extremely ephemeral prints left if, say, an animal with wet feet has walked across a dry surface. At the other extreme, very soft surfaces, while allowing a print to form, are not always that helpful when it comes to identification. This is because mediums such as snow and dry sand are so soft, prints may end up much bigger than they really are.
The very best surfaces have a Goldilocks-like in between level of give, not too hard, not too soft. Best of all is firmer mud, especially that composed of fine silt. This produces well-defined prints that hold their form longest and accurately reflect the actual size of the feet that have made them. That being said, snow and sand still allow prints to form and reveal a glimpse of the wildlife around us. There is something magical about seeing a fresh trail of animal prints in an otherwise unsullied snowy landscape, after all. It is just that you might not find it as easy to see a clear enough print to identify the exact species involved.
Counting Toes
When it comes to identifying the animal that has made a print, there are a few key things to look at that will help. With non-hoofed mammals, one of the most helpful features is how many digital, or toe, pads there are. Different mammal groups have a different number of toe pads. Mustelids such as badgers and stoats, for example, have five toe pads on both fore and hind feet. Most rodents, meanwhile, have four-toed front feet and five-toed hind. Cats and dogs, including foxes, have four toes front and back. Remember, though, that a less well-defined print might not show all of an animal’s toes. Another thing that can confuse toe counts is what is called ‘registration’. This refers to an animal placing its hind foot all or partially within the front footprint. The combination of two prints in one can make it difficult to see how many pads there are.
Two further useful identification aides are the interdigital and proximal pads behind the toes, although not all prints show the latter. Interdigital pads are raised sections on the central sole of the animal’s foot. Proximal pads, if present, are on the heel. The number and arrangement of pads vary between species. Badgers, for instance, have a more or less single, large interdigital pad behind the toes and a single, large proximal pad on the heel. Otters have a three or four-lobed interdigital pad and, in good conditions, a single proximal pad. Foxes have a single triangular interdigital pad but no proximal ones. Rabbits and hares leave no interdigital or proximal pad marks. The rear footprints, though, can show the characteristic long marks of their elongated rear soles.
Cloven Hooves
Ungulates, or hoofed mammals, have much simpler footprints. Deer, sheep, cows and pigs are all even-toed ungulates with two toes, sometimes referred to as a cloven hoof. The individual toe prints are called ‘slots’. Deer and sheep prints can be quite difficult to tell apart, although the setting and habitat can sometimes help rule one or the other out. Sheep hooves are often more rounded at the tips, though. Telling deer species apart is also difficult, although size and species range can give some indications. Muntjacs, for example, haven’t yet reached Scotland. At just 2.5cm long, their prints are also very small compared to fallow, sika and red deer, although will overlap with prints produced by those species’ fawns.
Another species’ prints that you are increasingly likely to encounter in the UK are those of wild boar. Once widespread in Britain, they were hunted to extinction in the late 1300s. A combination of accidental escapes and deliberate releases from farms, there are large populations in the Forest of Dean and southeast England. There are smaller numbers in parts of Scotland, Devon and Dorset. As well as two slots, wild boar prints sometimes show two marks at the back of each footprint. These show the dewclaws, vestigial digits higher up the foot than the full hooves. Because the dewclaws are fairly low down the leg in wild boar, they nearly always leave a mark. Although many other animals also have dewclaws, from deer to dogs, if they are higher up the leg, they are very unlikely to reach the ground and leave a print.
Digging Deeper
There are a few other pointers to print identification. Size is a fairly obvious clue. Badger prints are large and heavy, measuring up to 6cm by 5.5cm. They often include visible long claws, as well. Of our mustelids, weasel prints are smallest, measuring on average just 1.5cm by 1.3cm. Mice and rat prints are also, unsurprisingly, extremely small. Although some domestic dog breed prints are the same size as those of red fox, dogs have a much larger and more obvious interdigital pad. It is generally much larger than the digital pads. In foxes, the interdigital pad is roughly the same size as the digital ones.
In addition to footprints, a few animals leave tail drag marks. If conditions are right, otters, mice, shrews, rats and beavers all leave tail drag marks. In three of our mammals, webbing between the feet can also sometimes be visible if the ground is suitably soft. In otters and the invasive non-native American mink, all four feet are webbed. In beavers, just the hind feet. Where the ground surface is just right, prints can even reveal hair between the various pads. Claw marks, meanwhile, are usually a bit hit and miss so not something to rely on for identification purposes.
Bird Prints
Because of their similarity, it is much more difficult to identify bird footprints to species level compared to mammals. However, they can at least be assigned to broad order or family groups. The toe arrangement and presence or absence of webbing is the usual clue to help with this. Passerine, or songbird, prints have three forward facing toes and one backward facing one, for example. UK woodpeckers, meanwhile, are what is known as zygodactyl. This means that they have two toes pointing forwards and two backwards. Gulls, ducks and geese all have three forward-facing webbed toes, with just a tiny hint of a back toe sometimes showing.
As well as being harder to pin down to species level, bird prints are also less common in all but the softest of surfaces. Sand and snow are, of course, soft enough to produce a mark. But as these surfaces tend to collapse or melt easily and make the prints appear larger, they are not usually any easier to identify. Although always nice to see, because birds are much more visible creatures than mammals, their prints are ultimately not as sought after when it comes to surveying or recreational wildlife watching, either.
Fantastic Footprints
Whether it is for our work or while out and about on our days off, animal footprints offer a wonderful glimpse of the otherwise hidden lives that share our world. We may not often be lucky enough to spot the animals themselves, but these lovely traces are surely the next best thing. And sometimes there is enough information, as well, for us to be able to identify the animal in question, which is a real bonus.
