Sunday, 26 February 2023

The Raccoon Family: The True Raccoons

Common raccoon
While the raccoon family contains more species than most people likely realise, by far its best-known example is the animal for which it is named. The common raccoon (Procyon lotor), alternatively known as the "northern raccoon" or simply "the raccoon" was the first species in the family to be scientifically described, no doubt because it's not only common and widespread, but because it's a very distinctive animal. Everyone must surely be familiar with what they look like, and, if you're North American, there's a decent chance that's from first-hand experience.

The common raccoon is found across almost the whole of the contiguous United States, barring only some of the drier parts of the Great Basin, as well as across southern Canada and virtually all of Mexico and Central America. Furthermore, raccoons were introduced to Germany as a hunting animal in 1927 and, with the help of others that escaped from fur farms, since around the 1970s they have been expanding rapidly across Europe. Over the last couple of decades, they have established populations from Spain and France in the west across to Russia and Ukraine in the east. In the 1990s, they were also introduced to Japan and they have also been introduced to Uzbekistan and other parts of Central Asia, probably following escapes from fur farms.

While its natural habitat is probably riverine areas the common raccoon is highly adaptable, and can be found almost anywhere, including urban areas. This is due in large part to raccoons being amongst the most omnivorous of all mammals, willing to eat virtually anything. Their favoured foods in the wild seem to be crayfish and crabs but if those aren't available, almost anything else will do, with at least a third of their diet consisting of fruit, nuts, and seeds, and plenty of worms, insects, eggs, carrion, and some small vertebrates. Most notably, of course, they will search through human refuse, allowing them to become established even in highly urbanised areas.

The word "raccoon" comes from the Powhatan language of pre-Columbian Virginia and has been borrowed from English into some other languages. In most western European languages, however, the name for the animal is a more-or-less literal translation of the phrase "washing bear" (as was the original scientific name), while in French, it's a "washing rat". Even Spanish and Portuguese, which more commonly uses names taken from native Mexican and Brazilian languages respectively, have an equivalent term as an alternative.

These terms come from the well-known habit of raccoons washing their food in water before they eat it. Quite why they do this is unclear, since they're no more likely to do it if the food is dirty than if it's already clean. It's far more common in captive animals than it apparently is in the wild and may simply be a carry-over of their normal behaviour of feeling about in streams to find food with their paws, and they will still go through the hand motions when handling food even if they don't have any water to do it in.

Raccoons are nocturnal by inclination, and in northern latitudes sleep through a significant part of the winter; this is not, however, true hibernation, as their body temperature doesn't drop significantly. In the wild, they typically live alone with a population density of around 3/km² (8/square mile) in prairie and twice that in forest, where food is presumably more plentiful. In agricultural land, however, they can be much more common, and in cities even more so. A 2002 report from a 71-hectare (175-acre) park in Fort Lauderdale identified no fewer than 169 raccoons living there, although this is probably something of an upper limit.

Such high urban population densities also indicate some plasticity in how raccoons arrange their social lives. In the wild, males are territorial; females are more obliging of their sisters but they still don't actually live together. Both sexes use scent-marking and they are capable of distinguishing individuals by the scent of their urine. While most follow the usual mammalian pattern, where young males wander off in search of mates but daughters stay close to their mothers, in areas of low population density both sexes seem equally likely to leave home once they are old enough to do so - this may be another factor in their rapid spread both in areas where they are invasive and across much of the US since the end of widespread hunting in the 1930s.

While the amount of land required to support a raccoon where rubbish bins are common is considerably less than out in the prairie, and the racoons do stick to smaller areas as a consequence, they are still forced to bunch up. Perhaps because females are so abundant, the males stop bothering to compete for territory, and may even gang up together in small groups. As a result, although wild raccoons are often serially monogamous in practice, in areas of high population density females will have multiple mating partners, and it is not unusual for a single litter to include kits with different fathers.

Cozumel Island raccoon

Being as adaptable as they are, it's no surprise that raccoons will basically mate whenever they feel like it, although February to March does seem more common in the wild, with the young being born 63 days later. Three to four kits per litter is about typical and while some will stay with their mother through the first winter, they will all have left by the following spring. 

Raccoons are known for their high intelligence, something that humans may find more noticeable due to the animals' high manual dexterity. For instance, while they don't go as far as spontaneous tool use, they can be trained to drop stones into a tube of water until a floating food item comes within reach and, once they've got the hang of it, can be innovative in figuring out the best way of doing so. They can also count to three, which is more than most animals can.

I mentioned in my previous post that four raccoon populations in the Caribbean were thought to represent separate species until it was shown that three of them were simply recent introductions of the mainland species. The one exception is the Cozumel Island raccoon (Procyon pygmaeus). Although it has been questioned, the general consensus at present is that does represent a genuine species. The oldest local remains come from Mayan archaeological sites dating back over a thousand years, so they certainly aren't a recent introduction, and genetic evidence suggests that they last shared a common ancestor with their mainland kin between 47,000 and 21,000 years ago. 

In itself, that's not enough to prove status as a species, and it's certainly true that the Cozumel Island species is remarkably similar to the mainland one. They are however, a good 15% smaller, which does add to the evidence of their unique nature. They live in mangrove swamps but it's worth noting that this is because there is almost nothing else on Cozumel Island, which is only 478 km² (185 square miles) in area and lies 19 km (12 miles) off the east coast of the Yucatan Peninsula in southern Mexico. It does take advantage of agricultural land although not, apparently, of the only town on the island.

Relatively little is known of the animal, but what we do know suggests generally similar habits to its mainland counterpart. Over half of its diet consists of crabs but, again, this may be because there are a lot of them about on the island and the raccoon would probably be more omnivorous given the chance. Estimates for the total surviving population are no higher than a thousand and there may be many fewer than that. Combined with the relatively low genetic diversity and the fact that what little population there is tends to crash every time the island is battered by a severe hurricane (for example, Hurricane Wilma in 2005) the species is therefore currently rated as "critically endangered".

I mentioned above that the usual Portuguese word for "raccoon" comes from a native Brazilian language (specifically Tupi)... but you may have noticed that that's much too far south for there to be common raccoons. Instead, Brazil is home to the crab-eating raccoon (Procyon cancrivorus). In the far north, this does overlap with the common species, reaching as far as Costa Rica, but otherwise it's native to South America, being found across the continent east of the Andes as far as Uruguay and northern Argentina.

Crab-eating raccoon

There is no doubt that the crab-eating raccoon is a different species from its northern relative. Distinctive fossils date back to the Ice Ages, and the animal has a distinctive, if similar, appearance. While it is about the same size and shape as the common raccoon, its shorter fur makes it look smaller and skinnier, and it is also browner in colour, something that's especially notable on the feet.

Crab-eating raccoons inhabit areas with ready access to water, much as common raccoons prefer to, but they proven less able to exploit other habitats and generally avoid urban areas. As the name implies, they do eat plenty of crabs (as does the common species, given the opportunity) but they are omnivores, commonly feeding on plants such as seashore palm and bromeliad fruits. 

Despite being fairly common across much of its range - they are apparently the single most common roadkill in northern Brazil - there has been relatively little research on the crab-eating raccoon's habits or its biology, other than its basic anatomy. They are nocturnal, tend not to stray too far from rivers or other sources of freshwater and generally tend to be solitary when they aren't breeding or looking after young, but that's about it. In all probability, they are otherwise similar to the northern species.

Taken together, these three animals are the only species commonly referred to as "raccoons". Everything else in the raccoon family is a "procyonid" but, strictly speaking, not a raccoon. Nonetheless, two other species in the family live in the US and next time I will be looking at one of those, together with its close relatives further south.

[Photos by "Fazalmajid", Christopher Gonzalez, and Steven G. Johnson, from Wikimedia Commons.]


  1. Brazilian names: guaxinim (Native Tupi word), pronounced gwah-shee-neen, and mão-pelada "naked hand"

    1. Yeah, those are the Portuguese words I found, with guaxinim being used more generically, and mão-pelada for the crab-eating species specifically.