Creepy Creatures #3: Blow Your Nose, Toad

NOTE: This post contains disturbing/gross photos.

Obviously when talking about Halloween-ish animals you will eventually come across the humble toad. Ah, toads; they were one of my favorite things to catch as a small child, especially the little ones that would squeak angrily if you picked them up. I’m pretty sure there’s a picture of me somewhere covered in dirt while holding like seven toads with one on each shoulder. I’ll have to dig that up and put it on the blog.

…Anyway, where was I? Right, a post on toads. Well, I was looking up what sort of toad-related topic I could discuss and was drawing a blank until I heard about a certain fly named Lucilia bufonivora.

Let me apologize in advance to all the toads I ever harassed as a kid, and in fact to every toad ever, because damn, you guys don’t deserve this.

I'm also sorry that toads think that this posture is the scariest thing ever. (Photo by Łukasz Olszewski.)

I’m also sorry that toads think that this posture is the scariest thing ever. (Photo by Łukasz Olszewski.)

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Creepy Creatures #2: Rodent Plagues

Photo © Animal Planet

Photo © Animal Planet

We’re not talking bubonic plague here- we’re talking biblical.

With 2,227 individual species identified, members of the order Rodentia make up about 40% of all mammal species. The rat and mouse family, Muridae, makes up 700 of those species by itself. The small-bodied, fast-breeding, gnawing omnivore is clearly a highly successful body plan in almost any environment.

But there’s “successful” and then there’s “too successful.”


Murids have evolved to be opportunistic, taking advantage of resources whenever they find them: if they come across a steady food source, their population can swell exponentially.

In nature, there are gradual patterns of feast and famine, especially in seasonal areas, and animal populations naturally go up and down with the availability of food, abundance of predators, etc. In stable environments, this will result in cyclic population patterns.

Graph of the cyclic, sometimes dramatic, nature of lemming populations. (Contrary to popular belief, the decreases in population do not occur due to mass lemming suicide.)

Graph of the cyclic, sometimes dramatic, nature of lemming populations. (Contrary to popular belief, the decreases in population do not occur due to mass lemming suicide.) Source.

In especially good years, of course, the populations will go up more than usual. And when conditions are really, really good- well, that’s when things get interesting. Did I say interesting? I meant terrifying.

When humans started farming, way back in the day, they started the concept of surplus crop. Not surplus like the buried acorns of a squirrel or an Arctic fox’s dead duckling hoard, no. We’re talking silos of grain. Silos! Hundreds of pounds of grain! Can you imagine the first little mouse seeing those silos and sending a grateful little mouse prayer to mouse god in mouse heaven?

Now, for most animals, even a massive surplus of food wouldn’t make the population get too out of hand if it was all clustered in one place. This is because many animals are territorial and intolerant of having too many unfamiliar individuals near them at one time. Indeed, this is even true for most rat and mouse species, as social as they tend to be.

It may be, however, that the increase in available food is not the only factor driving the population explosions in rodents; in fact, several studies have found that there is a natural upper limit in population size no matter how much food they provided. So things shouldn’t get too bad…

…Except they do.

If you live in Australia, especially if you come from a farming family, the words “mouse plague” probably mean something to you. Probably something that is not entirely positive.

Flash back to 1994. It was a good year for crops; there was an unusually high amount of rainfall, and yields were wonderful. But it wasn’t just wonderful for the farmers- the humble house mouse was celebrating too.

Now, these mice are not native to Australia; they were imported along with people. But like many rodent species, they settled in to the relatively placental-free environment, exploiting niches that no native species had yet explored. Farmers were certainly already familiar with the frustrating mouse booms that frequently came hand-in-hand with successful yields. But in 1994, it got ridiculous: the field mouse population swelled to an estimated 500 million.

Here is a video about that particular plague, though I will warn that it contains scenes of mild gore, dead animals, and of course an uncomfortable amount of mice.

This isn’t a case of “oh, ew, a few mice,” this is “we can’t drive on the roads because our cars skid over mice,” this is “we can’t put on our shoes without having to dump out ten mice first,” and this is, most terrifyingly, “we go into our barns and see our farm animals being literally eaten alive by mice.”

That year mice destroyed 500,000 tons of wheat, or 30% of the country’s crop, costing billions of dollars. Thankfully, it didn’t last long- after a few months, the population eventually burned through the available resources and crashed.

(Say, human populations sure have been increasing pretty sharply for the past few years, haven’t they?)

While the 1994 Australian mouse plague is one of the most extreme plagues ever recorded, it’s certainly not the only one. As long as humans have been farming, there have been rodent plagues- records of rat and mouse infestations span as far back as ancient Egypt (no doubt spurring the domestication of the housecat!)

Australian farmers pose behind a massive pile of poisoned mice in 1917.

Australian farmers pose behind a massive pile of poisoned mice in 1917.

Today, such plagues are rare in places such as the US and most of Europe, but they are common in places such as China and India; anywhere there is a temperate climate with a good chance of heavy seasonal rainfall runs the risk of a rodent plague.

In the video above you can clearly see mice living shoulder-to-shoulder, having to crawl over top of each other, and literally flowing like waves because they are packed so tightly together. How could any animal tolerate these living conditions? As I mentioned before, there is a limit to how much contact even highly social animals will tolerate.

There are a couple of theories floating around as to why these rodent plagues occur. First, they occur most often under specific circumstances: a drought period spanning 1-2 years followed by a significant rainfall. But plagues don’t always occur even when these conditions are met, though their frequency of occurrence is- at least in Australia- actually starting to increase.

One of the most interesting theories for why rodent plagues only occur sometimes in seemingly ideal conditions is that rodents have “increase” phenotypes- that is, some mice have a specific set of behavioral traits that can lead to massive population increases, while others have a set of traits that leads to more gradual population increase. If not enough mice with “increase” phenotypes are present in the population, a mouse plague can’t occur even in the best of situations.

Interestingly enough, these “increase” phenotypes bear striking similarities to behaviors we select for in our own domesticated animals: increased social tolerance and docility, high reproduction rates, low infanticide rates, low dispersal rates, and low rates of territorial aggression. In other words, a surplus of more “tame” mice in the population might be what triggers these plagues. A population crash occurs when a combination of factors like increased mortality via disease, starvation, predation, etc. and/or an increase of the alternative, more aggressive and territorial phenotype arises.

The most terrifying thing about it all is that there is almost nothing we can do if a rodent plague happens. Short of raining poison down on the animals (which the Australian government has done), no amount of traps will get rid of such a horde once it appears. All the farmers can do is wait for the population to crash and hope that they won’t literally be eaten out of house and home.

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To view a list of all my animal articles, head to the Nonfiction section.


Rat plague hits northwest China

Rat plague in India

Sources/Further Reading

FAQ about Australian mouse plagues

Boonstra, R., Krebs, C. J., & Stenseth, N. C. (1998). Population cycles in small mammals: the problem of explaining the low phase. Ecology79(5), 1479-1488.

Krebs, C. J., Chitty, D., Singleton, G., & Boonstra, R. (1995). Can changes in social behaviour help to explain house mouse plagues in Australia?Oikos, 429-434.

Mutze, G. J. (1991). Mouse plagues in South Australia cereal-growing areas III. Changes in mouse abundance during plague and non-plague years, and the role of refugia. Wildlife Research18(5), 593-603.

Saunders, G. R., & Giles, J. R. (1977). A relationship between plagues of the house mouse, Mus musculus (Rodentia: Muridae) and prolonged periods of dry weather in south-eastern Australia. Wildlife Research4(3), 241-247.

Singleton, G. R., & REDHEAD, T. D. (1990). Structure and biology of house mouse populations that plague irregularly: an evolutionary perspective. Biological Journal of the Linnean Society41(1‐3), 285-300.

Ylönen, H., Jacob, J., Runcie, M. J., & Singleton, G. R. (2003). Is reproduction of the Australian house mouse (Mus domesticus) constrained by food? A large-scale field experiment. Oecologia135(3), 372-377.

Previous Creepy Creature: Ghost bats!

Creepy Creatures #1: Ghost Bats!

Ghost Bat

Photo by Bruce Thompson

Happy October! To celebrate the spookiest month of the year, I’ll be posting a series of short articles on bats, cats, rats, and all kinds of creepy critters!

You may have heard of vampire bats, but have you heard of… GHOST BATS?

There are actually three species of bat with the word “ghost” in their name: the ghost bat of Australia, Macroderma gigas, the Northern ghost bat, Diclidurus albus, and finally the ghost-faced bat, Mormoops megalophylla.

Ghost bat! Photo by Gina Barnet.

The ghost bat (which is also, funnily enough, known as the false vampire bat) likely gets its name from its pale fur and adorable ghoulish expression. It is an Australian species that ranges in color from the sooty-grey Queensland morph to the near-white desert morph in the west.

It is a big bat, one of the largest members of microchiroptera with a two-foot (60 cm) wingspan. Insects alone don’t satisfy this ghost’s spiritual needs; it hunts small mammals, reptiles, frogs, birds, and even other bats. It is actually the only carnivorous bat in Australia.

Like their spooky namesake, ghost bats are elusive and very hard to spot.

by Merlin Tuttle

Northern ghost bat. Photo by Merlin Tuttle.

The Northern ghost bat is often mistaken for the similarly-colored Honduran white bat for their color and the fact that both have a habit of roosting on the undersides of palm leaves. Perhaps this is why it always has such an irritated look on its face- the two species are not even closely related.

The Northern ghost bat is found across Central and South America, though it is rare in all parts of its range. It’s a small fellow with a wingspan of up to three inches (7 cm). Despite this, it still manages to eat about 1,000 insects a night.

Unlike most bat species, the Northern ghost bat is solitary outside the breeding season and normally roosts by itself.

Art of a ghost-faced bat. Look up the real thing if you don’t believe me.

The ghost-faced bat is the only one in the group not named for its color, but rather that attractive countenance. It’s found from Texas to Venezuela, roosting in colonies up to 500,000 members strong. Just think of looking up and seeing 500,000 of those faces staring down at you from the ceiling.

It’s got a 15 inch wingspan and it eats insects, but you don’t really care, right? All you want to know is why, dear lord, why does its face look like that.

The answer is that nobody freakin’ knows. Seriously, I haven’t found so much as a theory as to why their faces look like that. There’s no sexual dimorphism between males and females, so it can’t have anything to do with mate choice, and as far as we know their insect diet isn’t particularly specialized to warrant unusual headgear… maybe it’s simply customary for baby ghost-faced bats to smash face-first into a cave wall on their first flight?

The best info I could dig up was the fact that there is a heavy concentration of sebaceous glands around the ghost-faced bat’s skin folds, so it may somehow be involved in scent communication. Who knows- there really hasn’t been too much research done on them.

The ghost-faced bat is actually a member of the genus Mormoopidae, which is a nice collection of uniquely hideous characters with such names as the sooty mustached bat or the big naked-backed bat.

Here is a sooty mustached bat. Charming. (Source.)

None of them really get to the level of the ghost-faced bat, of course. As far as scariness goes, it is the winner of this round.

Anyway, hope you enjoyed this brief overview of the three spookiest bats of them all!

Next creepy creature!

To view a list of all my animal articles, head to the Nonfiction section.


Patrick the Ghost Bat

Sources/Further Reading

Hudson W.S., Wilson D.E (1986). “Macroderma gigas”Mammalian Species 260 (260): 1–4.

Lim, B., Miller, B., Reid, F., Arroyo-Cabrales, J., Cuarón, A.D. & de Grammont, P.C. 2008. Diclidurus albus. The IUCN Red List of Threatened Species. Version 2014.2.

Rezsutek, Michael and Guy N. Cameron. 1993. “Mormoops megalophylla”Mammalian Species (American Society of Mammalogists) (448): 1–5.

Steinway, M. 2000. “Mormoops megalophylla”. Animal Diversity Web.

A Few Tips for Understanding and Applying Scientific Research

I am frequently disappointed by the way I see science being taught in the US- no idea if it’s the same or different in other countries. What disappoints me is a tendency to focus almost exclusively on “how to design an experiment” with little to no education on how to understand and interpret scientific results.

The only time I actually really got any focus on this at all was in college, and even then it was sort of a haphazard focus. Students are somehow expected to intuit a lot of this knowledge on their own.

I’m not really making this post to specifically remedy the issue, but I do hope that some of these suggestions will help you think more critically about how and why research is used.

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Eusociality and Other Sex-Free Lifestyles

Why Members of Sexual Species May Choose to Stay Chaste

Sometimes I hear people making derisive comments towards people who prefer not to have sex, something along the lines of how it goes “against nature” to never have sex, therefore something is horribly wrong with them, etc., etc.

The specific plague I wish upon those unpleasant people is an infestation of termites. Why termites? I’ll talk about that in a bit.

May all your dwellings look like this, jerk. "Termite damage" by Alton - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

May all your future dwellings look like this, jerk. (“Termite damage” by Alton. Licensed under CC BY-SA 3.0 via Wikimedia Commons.)

At one point highly social behavior presented kind of a paradox to the traditional, selfish-gene style evolutionary theory. Charles Darwin famously admitted that it was the social behavior of the bee that was going to bring down his entire construction, because most bees- nay, the vast majority of all individual bees spend all their times leading pious, sexless lives centered around helping one other bee reproduce. At the peak of the season, honeybee colonies can have 60,000 nonbreeding individuals- and just one sexually active queen.

Darwin, of course, did not yet know about genes, but he had an inkling that heredity was a clue- that by helping their relatives, the bees were actually helping themselves. Later scientists have filled in more of the gaps using modern molecular science, and yes, from a genetic standpoint, helping a relative is something like helping a piece of yourself.

But at what point does the value of helping close relatives outweigh the value of actually reproducing? That is a question biologists have been grappling with for quite a while. Because in the game of evolution, what matters isn’t how big your species’ population is- what matters is how many of those individuals share your genes.

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Canid Scent Marking (or, Why Dogs Pee on Things)

I took a lot of pictures of dogs peeing on things for this article.

Exhibit A, Razzle.

Exhibit A, Razzle.

If you own a dog, have walked a dog, or just have seen a dog on TV, you have probably seen a dog peeing. Particularly that stereotyped male raised-leg posture that Razzle is demonstrating above. (In this case, stereotyped refers to a fixed and repetitive set of movements, not a form of doggie-profiling.)

Dogs have a better sense of smell than we do. Heck, most mammals do; we just happen to be in a group- the simians- that ended up using vision a lot more than scent. At some point we more or less lost a means of communication that is absolutely fundamental to the lives of our hairy, warm-blooded cousins.

I’ve talked a bit before about how basic biological behaviors- such as sex or grooming or eating- can be co-opted by evolution to have a social meaning. For canids, urination has become a huge part of how they exchange information with one another.

We have a hard time studying this behavior because of our own limited sense of smell, and I think we are only beginning to grasp just how complex this scent-based communication can be.

I am about to tell you more than you ever wanted to know about dog pee.

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Dominance Behavior in Canids


Muzzle-biting behavior. (Source.)

I didn’t really even WANT to make a post about this.

The alpha-beta-omega model of wolf packs is dead in scientific literature, hammered into the ground, so to speak, and it’s been dead for over ten years. So why am I still hearing about it on TV and reading about it in articles? Why are popular dog trainers that encourage you to “be the alpha” still taken seriously?

I think the unfortunate truth is that the idea that there are strong and ferocious leaders in wolf packs and that you, too, can take on that role with your dog is just somehow appealing to people. Almost romantic, in the older sense of the word. And because of this, it makes money. It sells werewolf media. It sells dog training classes. Educational science channels that have no business promoting this false ideology keep it on board because it gets people watching.

If you couldn’t tell, I’m pretty fed up with the whole thing.

Okay, let’s talk about dominance, particularly what the word even means, because popular media does a terrible job of explaining it.

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The Raccoon Dog

The tanuki is a raccoon dog, but not all raccoon dogs are tanuki.

Sorry, I wanted to clarify that right up front, because I see this mistake made all the time. The word tanuki refers to the Japanese subspecies, not the entire species, which has a range quite a bit larger than just Japan.

You may be reading this thinking, “Koryos, I don’t know what a tanuki OR a raccoon dog is, can you please show me a picture.”


Photo by Tim Ellis.

Be careful. It’s cute. (Photo by Tim Ellis.)

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Animals Masturbate Too- And Why That Matters

Juvenile rhesus macaque at the Beijing zoo. (Not Peanut.) Source.

Juvenile rhesus macaque at the Beijing zoo.  Source.

I have had my leg humped by a very small monkey named Peanut.

Peanut herself did not think that this was anything out of the ordinary; in fact, as she enthusiastically gyrated on my thigh, she kept glancing backwards to meet my eyes, her little face arranged in what seemed to be a contented expression.

At the time, Peanut and her companions at the rhesus macaque nursery I volunteered at were all less than three months old. They were just beginning to develop more complex behaviors than the scream-eat-poop trifecta (not that those three were any less present). The males were beginning to manipulate their own penises, and both sexes would frequently engage in enthusiastic humping sessions with objects and other monkeys. The other monkeys weren’t always thrilled about this.

I suppose this would make you imagine that the nursery just became a masturbatory frenzy at this point, but that really wasn’t the case. The vast majority of the time wasn’t spent in sexual exploration but in actual exploration, of their home spaces, of toys, of social behaviors like grooming, playing, and fighting.

I guess where I’m going with this is that when many humans are confronted with the idea of animal sex, they tend to fly to extremes: either animals are sex purists and only have it with the intent of reproduction (and NEVER use contraception!) or animals are hedonistic, lustful creatures that will spend every moment that they can touching themselves.

I think that this is because admitting that sexual behaviors- reproductive or not- make up a small but important part of an animal’s life is somehow more uncomfortable than either of those options. Perhaps it just hits a little too close to home.

But, as the title states, I am about to argue about why the study of animal masturbation (and other aspects of animal sex) is important. It matters. It matters for the ethical treatment of animals, it matters for conservation, and it matters because the study of something shouldn’t be limited by the fact that many people want to pretend that it never happens.

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