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rat

Random Rodent: Acacia Rat (Thallomys paedulcus)

by JR Kinyak on October 10, 2011

in Operations,Rodents

Acacia rat (click image to enlarge)


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I know you’ve heard it before, but the rodents are a problem. They account for some 40 percent of the mammals, and nearly all of them are small beige lumps. Many of them have evaded photographers up to now, so I often have to base my drawing on a related rodent but make changes based on the descriptions I can find. It’s often hard to force myself to draw a one of the little guys when I could be drawing a monkey or a carnivore. So every now and then, I’ll be letting random.org choose a rodent for me to draw to add the element of chance.

Today’s mammal, chosen by random.org from all the rodents I have yet to draw, is the acacia rat, which lives in sub-Saharan Africa in trees, likely acacias, wouldn’t you think? According to the IUCN, “Thallomys paedulcus possibly represents a complex of several similar species. Further studies are needed to clarify the taxonomic status of populations currently allocated to this species,” so there’s another taxonomic quandary for us to ignore for now.

Acacia rats apparently make good pets—as good as our fancy rats Earl Grey and Doctor Who, according to some people.

Tagged as: random, rat, taxonomy

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Random Week: Gregarious Short-tailed Rat (Brachyuromys ramirohitra)

by JR Kinyak on April 14, 2011

in Rodents,Theme Weeks

Gregarious short-tailed rat (click image to enlarge)


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This week, I’m drawing mammals selected randomly by random.org. Each day, it’s a surprise to me, and this should be a good way to get through some of the mammals that I would be unlikely to choose on my own…like this one, the gregarious short-tailed rat. Nothing against him, but there’s very little information available about him and very few photographs for reference, and those are the ones I usually put off in the hopes that somebody will have taken pictures of them by the time I get around to them again. But picking them randomly doesn’t allow for that. And I have to tell you, it’s satisfying to draw one of the obscure guys, one where I have to really dig to find even a reliable description. It’s a job-well-done, wiping-my-hands-with-pleasure kind of feeling.

So, here is the gregarious short-tailed rat. He looks friendly enough, doesn’t he? These rats are endemic to eastern Madagascar, where they live in forests and fields, making grassy tunnels and evading capture.

Tagged as: random, rat

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Five Random Rodents

by JR Kinyak on April 8, 2011

in Operations,Rodents

Five random rodents (click image to enlarge)


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Rodents keep me up at night. I can hear them scritch-scritch-scritching in the attic and the walls. Their whiskers lightly tickle my skin and their buck teeth gnaw on my bones. Their beady little eyes stare at me from every corner, glinting in the dark. Not because my house is infested—it isn’t—but because of the Daily Mammal Rodent Problem.

Of the 5,000-ish mammal species in the world, 40 percent are rodents: small, toothy, bewhiskered, scurrying, and so nauseatingly beige. Tan. Grayish-brown. Buffy to tawny ochraceous with white underparts, if you want to get technical. In my database (the Smithsonian’s Mammal Species of the World), there are 2,278 ratty little pipsqueak rodents.

So there are thousands of them, but so what? Mammals are mammals, right? Right, but there are no photographs of many of these rodents. None! And they are boring. I would guess that 80 percent of them look alike. In fact, one family of rodents, Muridae, accounts for one sixth of all mammals in the world. Well, depending on how you count and whether you consider Cricetidae part of Muridae or its own family. I think. No rodent has ever been called charismatic megafauna, not even the largest rodent, the capybara, which I drew years ago.

They just aren’t fun to draw, which I could get past if they were at least easy to draw, but the lack of reference images makes it so frustrating. I have to find related species that people have taken photos of and then find descriptions of the species I’m actually drawing—see the above “buffy to tawny ochraceous with white underparts”—and sort of improvise. And I know that I take some liberties in my drawing, I mean, my work is not hyper-realistic and it’s not going down as the definitive record of what any given species looks like, but I still want to be accurate in my own way, and I have wicked perfectionist tendencies that make me uncomfortable when I feel like I’m falsifying anything.

So I’ve been putting the rodents off. My idea of drawing multiple rodents in one go has helped, but if I happen to pick one that appears to be short on reference, I’ll usually skip it, telling myself that maybe someone will take pictures of it in the next few years. I have been trying to draw rodents. I’ve drawn 108 rodents out of 380 mammals total, which means that 28 percent of my drawings have been rodents. It’s not 40 percent, but it’s not too bad. But I am still terrified that if I see this project through, I’ll be drawing nothing but anonymous beige furballs for the last decade.

This all brings me to my new idea, which is: Random Rodents! I went to random.org, which generates random numbers, and told it to pick five numbers between 104 and 2278, which were the numbers of the undrawn rodents in my database when sorted by…whatever, you get it, yes? It picked 1789, 1873, 903, 1565, and 980, I researched the rodents associated with those numbers, and here they are!

Notice that we got lucky with the porcupine; the other five, although varying from 7 centimeters to 20 centimeters in length, look like quadruplets. Sure, some of them have long tails and some have slightly shorter tails, and some are ochraceous to tawny while others are tawny to ochraceous, but all in all, I could probably just spend a week drawing generic beige mouse-like critters and no one would know the difference.

The porcupine is Hystrix cristata, a North African crested porcupine. The others, top to bottom and left to right, are Leopoldamys sabanus, the long-tailed giant rat; Pelomys campanae, the bell groove-toothed swamp rat; Punomys lemminus, the puna mouse; and Reithrodontomys paradoxus, the Nicaraguan harvest mouse. I’ll try to do a Random Rodents drawing once a week and together, we’ll force our way through this rat’s nest.

Tagged as: about drawing, mouse, multiple, porcupine, random, rat

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Rats Three Ways (Neotoma spp.)

by JR Kinyak on March 26, 2009

in Rodents

The Daily Mammal Book Club is discussing My Family and Other Animals by Gerald Durrell. Join in!

click image to enlarge

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Here are three rats for you! They’re in the wood rat or pack rat genus, Neotoma. Clockwise from the top left, we have N. cinerea (bushy-tailed wood rat), N. floridana (eastern wood rat), and N. lepida (desert wood rat). Wood rats are also sometimes called trade rats. Mammalian Species quotes a 1946 guide to the mammals of Nevada:

“It is supposed that when one of these rats carrying an object of its fancy comes to another more attractive object, it drops the first and continues on its way with the second. If the second object be the watch of a camper, who in the morning finds a piece of old bone where the watch lay when the camper went to sleep the evening before, he will think the name trade rat appropriate.”

Just, you know, hypothetically, right?

There are two words related to wood rats that you may not know. Both could prove useful in describing, say, someone’s housekeeping. Middens means a pile of bodily waste or a dunghill. Amberat is a deceptively beautiful word meaning crystallized rat urine. (I don’t know if it’s a portmanteau from amber and rat, but I hope so. I really love this word.) Here, in a book about the Grand Canyon, is a chapter all about amberat, and here is a photograph of it at UtahCaver.com. Apparently, it has a red-gold color and can be built up to several inches thick. It may or may not have a sweet smell.

Amberat helps fossilize wood-rat middens for later examination by interested parties. Archaeologists have found rodent middens that are 50,000 years old. The rats use the same middens for generations, so there’s all kinds of intriguing stuff in there. At Mesa Verde, they’ve found middens that show signs of exposure to smoke, suggesting that the wood rats coexisted with the Anasazi.

Tagged as: multiples, names, rat, words

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Mammals of Hawaii Week: Rats Two Ways (Norway Rat and Polynesian Rat)

by JR Kinyak on January 20, 2009

in Rodents,Theme Weeks

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As I write this, there are only about 11 hours left until Barack Obama assumes the presidency, which means we’ll be celebrating his home state for only a little while longer here at the Daily Mammal. The other day, we looked at the small Asian mongoose, which was imported to kill Hawaiian rats. Now, let’s meet a couple of the rats in question.

On the left is the Norway or brown rat, Rattus norvegicus. This rat came to Hawaii on European ships in the 19th century. The fellow on the right is a Polynesian or Pacific rat, otherwise known as Rattus exulans. It came centuries earlier in Polynesian canoes. These two species, as well as the black or roof rat, are responsible for the extinction of a number of Hawaiian bird species and the decline of even more, both because they prey on the birds and their nests, and because they compete with birds for food. They also carry a range of diseases and parasites. And they love to destroy sugarcane, pineapple, coffee, macadamia, and banana crops. They don’t think of it as destruction, though; to them, it’s just lunch.

The mongooses didn’t eradicate the rats of Hawaii, as it was hoped they would. Now, poison is the best way to get rid of them, and you can use electric fences to keep them out of places you’d rather they not visit.

We haven’t visited with Ivan T. Sanderson, author of Living Mammals of the World, in a while. Here’s what he says about one of today’s rodents:

“Although Man is undeniably ‘top-mammal’ in certain ways, and the Elephant may be regarded as the most highly ‘evolved,’ there is little doubt that some rat, and probably the Brown Rat (Rattus norvegicus) is actually the finest—in every sense of the word and especially in efficiency—product that Nature has managed to create on the planet today…Rats preserve a much more practical balance between compassion for and indifference to their own kind than we do. While weaklings or cripples among their numbers may be left alone, ‘fools’ and ‘criminals’ seem often to be deliberately eliminated or killed outright. All of this results in much sounder eugenics than we practice. That there are more individual Brown Rats in North America than there are people, is not the result of man’s carelessness, indifference, or wasteful and dirty habits; it is the result of the greater stamina and, frankly, commonsense of the rats.”

I don’t know about you, but I’m okay with our unsound eugenics! The Polynesian rat is called kiore in the Maori language, and it reached New Zealand, as it did Hawaii, in Polynesian canoes. In traditional Maori culture, the kiore plays an important part in ceremonies and mythology. You can read about that here in the Te Ara Encyclopedia of New Zealand.

Tagged as: humans, ivan, rat

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Rats Three Ways (Rattus lutreolus, Rattus fuscipes, Oryzomys palustris)

by JR Kinyak on January 13, 2009

in Rodents

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It’s always nice to knock off multiple rodents in one drawing. You have no idea how much the rodents gnaw at me. Forty percent of all mammals are rodents. Forty percent. As I’ve mentioned before, I did not consider that fact when I first thought, “I know! I’ll draw all the mammal species!” In order not to spend the last few years of this project drawing nothing but rodents, I should probably draw them three days a week. Would that bore you?

This particular drawing is one of those good exercises in perfectionism prevention for me. Sometimes I’m not at all happy with my work. But then I remember that there are 5,000 species, so I’m bound to dislike at least 500 of my drawings. Weird!

Shown here, clockwise from lower left, are:

Swamp Rat (Rattus lutreolus), who lives in Australia. This rat is notable, according to its species account in Mammalian Species, because “under experimental conditions, R. lutreolus was able to tolerate long periods of water deprivation. Intake of solid food and urine output declined during this period…The ecological significance of its extraordinary tolerance for water imbalance requires study.” Also, it has the shortest tail of all the rats in Australia. And other than the Tasmanian subspecies, it likes to live in wetlands.

Bush Rat (Rattus fuscipes), another Australian. Did you know there are Australian Alps? I didn’t, until I read that “although mainly a lowland species, R. fuscipes occurs in Australian Alps to 2,210 m.” in Mammalian Species. I could go on to tell you about what Mammalian Species describes as “a serendipitous discovery relating to dietary intake of fluoroacetate by R. fuscipes of Western Australia,” but I won’t. This particular species account is rather long, but in browsing through it, I see that “During major fires, R. fuscipes retreats into burrows; afterward it hides in deep accumulations of ash.”

Marsh Rice Rat (Oryzomys palustris), of the eastern United States, from southeastern Pennsylvania to the Florida Keys and as far west as Illinois. This rat is semi-aquatic, and like the swamp rat, it lives in wetlands. In several states, marsh rice rats are the main sustenance of barn owls, and they’re also preyed on by other owls, cottonmouths, water snakes, hawks, raccoons, foxes, mink, weasels, and skunks.

Tagged as: about drawing, rat

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Malagasy Giant Jumping Rat (Hypogeomys antimena)

by JR Kinyak on January 11, 2009

in Rodents

click image to enlarge

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Ah, Madagascar, an island of the strange and wondrous. The Malagasy giant jumping rat is another EDGE (evolutionarily distinct and globally endangered) species, which means that it’s irreplaceable…and at risk of disappearing completely.

This nocturnal forager lives only in one small part of western Madagascar, where it forages for seeds, leaves, and fruit. It’s the largest rodent in Madagascar. Like a rabbit, it has long ears and long back feet for jumping. It also occupies the same ecological niche that rabbits occupy in other places. Unlike a rabbit, it has only one or two babies a year.

The major threats to the giant jumping rat are climate change—specifically, aridification—habitat destruction, hunting, and introduced predators like cats and dogs.

Durrell Wildlife Conservation Trust page for the Malagasy giant jumping rat.

Tagged as: endangered, rat, threats

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