Jiggling on the Ecotone

It might leave a slightly different message if a human did it, but leaving piles of droppings in the territory around your home can be an important signal for many mammal species. Although making such piles visible may help other animals find them, the primary signal is, as one might expect, the smell. And not just the smell of the faeces, of course, but complex chemicals mixed in with it from urine or the secretions of anal scent glands. These can allow an animal with a sense of smell more subtle than our own to glean a lot of useful information about who left the deposit - and why.

In many species, this takes the form, not of solitary deposits, but of latrines. In the zoological sense, this refers to a single location for defecating shared by many animals of the same species. The animals who use the site may belong to a particular pack or herd, all using the same communal site, but they could equally well be rivals or neighbours leaving messages for one another. How the latrines are distributed can give researchers significant clues about what those messages might be.

The Importance of Blue Bullshit

Monkeys and apes in general, and humans in particular, have a relatively poor sense of smell but the same is far from true of most other mammal species. For such animals, scent can be an important method of communication and this is often done through scent-marking, leaving long-term messages that can be understood by other passing members of your species.

A common way to do this is by rubbing specially adapted scent glands onto objects - these glands are often on the feet or the sides of face, which is why many animals will rub their heads against things to mark their territory. An alternative is to either urinate or defecate in a particular location, the natural aroma of the excreta often being aided by anal scent glands. We are all familiar with a dog's need to mark its territory in this way and it's hardly alone in this respect.

This can provide all sorts of useful information to other animals from the same species, such as territorial ownership, social dominance, willingness to mate, and so forth. When the method used to deposit this information is defecation rather than urinating, the result is termed a latrine or midden - which, in the biological sense, are basically alternative words for "dungheap". Animals that use this method of scent-marking include rhinoceroses, lemurs, and antelopes. (And we can but wonder what human cities would be like had we evolved from a species that communicated in this way).

Armadillos Looking for Love

We can tell a lot about animals by simply observing where they go. While studies on wild animals can cover a wide range of different topics, many of which require close observation of what the creature is actually doing, many of the most basic simply require us to tag the animal with some sort of transmitter and watching it move remotely.

Of course, while I say 'basic', this isn't necessarily all that simple to do in practice. You need to capture the animals, ensuring that they aren't overly stressed by the experience so that they modify their behaviour after the fact, and then you do need to spend a lot of time collating all the date, likely over the course of several months. Still, we do have many such studies for most well-known mammals. Some groups, however, have been comparatively overlooked.

Being Top Cat

If you happen to own a cat, especially an un-neutered male, you may have noticed that they sometimes pee on things. Shocking, I know.

Spraying is just one way that cats leave scent marks, whether to warn other cats away from 'their' territory, or to advertise their availability to members of the opposite sex. And, as we'd reasonably expect, this is as much true of large wild cats as it is of the domestic moggy. Indeed, we have a reasonable understanding of how some wild cats use these markings. For instance, we know that, just as in the domestic animal, male North American cougars spray more than females, both to mark their territory and to advertise for females.

The Family Lives of Japanese Badgers

As I mentioned previously as part of my overview of the weasel family, we used to think that the "common", or Eurasian, badger inhabited much of that continent, with individuals found from Britain to Japan. We now know that that's not the case; there are at least three different species of badger within this area, albeit very closely related.

In Britain and Ireland, we think of badgers as living in communal setts, with multiple different family groups sharing the same network of tunnels and chambers, that may have built up over generations. Yet, while this is true in the British Isles, it isn't true anywhere else, even when we are looking at the exact same species where it lives on continental Europe. Here, as with most other members of the weasel family, European badgers live alone when they aren't raising their young.

The reason for this is thought to be a combination of Britain's climate and a diet rich in earthworms.The frequent rains in the British Isles are good for earthworms, and there are so many available to eat that the badger population in the islands is unusually high, something that they deal with by crowding together in larger groups. Elsewhere in Europe, there are less earthworms, and the badgers have a broader diet, but one that requires them to defend their territory from others of their own species if they don't want to starve.