Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"

For a change, I bring you an American mammal species today. These are Black-Tailed Prairie Dogs, Cynomys ludovicanus. Now again, as happens often in these articles, I note that there's some taxonomic misattribution here. Prairie dogs are not dogs! They're actually � what do you think they are? Certainly, they're rodents � but what kind? They're members of the Squirrel Family, the Sciuridae. They may not look much like typical tree-living squirrels, but the family is amazingly diverse and includes many ground-living species in Africa, Europe, Asia and the Americas. These little rodents got their name from their barking calls – and of course their prairie-living lifestyle. The scientific name means 'Lewis' Dog-Mouse'. The 'Lewis' in question is of course Meriwether Lewis, who together with William Clark mounted the famous expedition of discovery westward over the continental USA. They encountered the prairie dogs in 1804, but noted that French folks were already aware of them. But the expedition brought them to the notice of Science, and they were officially named in 1815.

This is just one of five species of prairie dog in the world, but it is the most widely distributed of them all. They used to be incredibly abundant in the past. They lived in virtually all of the prairie country from Alberta in Canada southward to Chihuahua in Mexico, over a wide grassy belt crossing the entire USA. In their glorious past, they lived in immense colonies or 'towns', the largest of which was encountered in Texas and noted as being 100 miles wide, 250 miles long, and containing 400 million animals!

Prairie dogs themselves are rather small, weighing 1 to 3 pounds as adults. They have short, black-tipped tails and almost absent ears – so these would not get in the way in their tunnels. They have long claws, especially on their front feet, for digging.

Digging defines the prairie dog lifestyle. They have long underground tunnels with many above-ground openings, often surrounded by a mound of soil and litter. They compact the soil in these rims with their noses, which makes it difficult for seeds to germinate there. They can have 20 to 57 burrows per acre of suitable territory. Inside the tunnels, they have 'resting' rooms close to the surface from where they can hear if there's activity above, and deeper rooms with nests made of dry grass. Prairie dog 'towns' can stretch over many hectares, but inside them the residents are usually divided into smaller groups called coteries, usually made up of an adult male, one to three females, and their recent offspring. The young are born in the nests, naked, blind and helpless; at the age of 30 days, they open their eyes, but remain underground for seven or so weeks. They mature at 15 months and usually can breed in their second year, but in years of abundant plant growth may even start breeding aged one year. In the wild, they rarely live more than four years, but in captivity can reach the age of eight.

Although prairie dogs spend so much time underground, much of their life activity takes place on the surface. They're vegetarians, eating mostly grasses, but also some herbs and the leaves of low shrubs. They hardly ever drink, getting their moisture from plants such as succulent prickly pear cacti. They are active by day, unless it rains or is very cold or extremely hot. Unlike other rodents like groundhogs, they don't hibernate in winter, instead spending the cold nights in torpor, with reduced metabolic activity, but coming out, even if just for a short while, during at least some of the days. Even so, they lose can lose as much as a fifth of their bodyweight over the winter.

Being small, prairie dogs are very vulnerable to a variety of predators: coyotes, badgers, bobcats, eagles, hawks, rattlesnakes and more. They warn others by a variety of barking calls which can be amazingly nuanced. They have a territorial call named a 'jump-yip' during which they straighten their body up and throw their front feet upward. This usually 'infects' nearby prairie dogs to do the same, causing a 'wave' that shows their alertness to potential predators. But against their worst threats they have no defense. They suffer most heavily from human destruction of their habitat for farmland, and from direct hunting and poisoning. Another silent danger they're very susceptible to, is sylvatic plague, caused by the same bacterium that, through infected rats, caused the Black Death and bubonic plague in humans.

One prairie dog predator that used to be very prevalent is today almost extinct – the Black-Footed Ferret. This lithe little carnivore is excellently shaped to enter prairie dog burrows and grab its victims. Sadly, the ferrets suffered even worse than the prairie dogs as a result of sylvatic plague outbreaks, exacerbated by human poisoning campaigns of the prairie dogs. The ferrets have been brought back from the brink through intensive conservation campaigns.

The prairie dogs themselves don't really deserve their persecution at the hands of humans. They are incompatible with intensive crop farming, but can survive well, if tolerated, on cattle farms. Though they eat the grass, they also eat some other plants not targeted by the cattle. And even their feeding, digging and defecation activities stimulate the growth of the grass – which may as a result even have higher protein content than grass on prairie-dog-free lands. Studies have thus far not found any significant decrease in the cattle-carrying-capacity of lands with prairie dog colonies. It takes about 250 prairie dogs to eat as much grass as one cow.

But in the overall wild ecology, prairie dogs are amazingly beneficial. They can be considered 'ecosystem engineers' or a keystone species. Their burrowing activity mixes up and loosens the soil, making it easier for plants to grow. Many animals shelter in burrows dug by them: other small rodents, cottontail rabbits, burrowing owls, snakes, and even the ferrets that prey on them. They keep large areas of land clear from dense vegetation, allowing easier access to seeds and insects, and allowing predators to be spotted from afar, and this attracts birds like meadowlarks, grasshopper sparrows and plovers. Large mammals like bison, bighorn sheep and pronghorn, can flourish around prairie dog colonies. Even in providing food for a large variety of predators, the prairie dogs provide a positive ecological service.

At present, though their overall population has been much decreased, this species is considered in no immediate danger of extinction. They can live in moderately-disturbed habitats, but suffer from extreme overgrazing or if the grass is otherwise eliminated. Thus, we need to consider the overall health of grasslands so as to ensure their safe existence. They've also suffered to a degree from being caught for keeping as pets. It is now illegal to do so in some states, but legal in others, sometimes with the requirement of a special permit. As pets, they can be charming and delightful, but are very social and thus shouldn't be kept unless a lot of time can be dedicated towards them.

Willem

13.11.23 Front Page

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