Creepy Creatures #5: PLANTS SCARE ME

We’ve done bats. We’ve done rats. We’ve done creatures of the deep and we’ve done toad maggots that creep. But in all honesty, do you know what scares me more than any of that?

Plants.

Ok, hear me out. I mean, you probably don’t spend a lot of time thinking about plants, much less being terrified of them. After all, they’re stationary, and they don’t have any mouths or eyes or brains, and any fool with an axe can go chop down a tree.

I mean, it's not like trees can drive.

I mean, it’s not like plants can drive.

But listen… there’s a major difference between plant biology and animal biology. I’m not talking about stamens and pistils and all that, I’m talking more fundamental. See, what with the whole stem cell research debate, most people generally understand that we are born with stem cells that turn into particular types of cells, like liver or bone marrow. But once those stem cells determine what they can be, they don’t ever change back.*

(*There are some exceptions to this. I own axolotls, after all.)

Plants don’t have to follow that rule. When you take a cutting from a branch of one plant and replant it, it can grow root cells from former branch cells. That’d be like cutting off someone’s leg and having a head grow out of it.

This distinction is important, because it means plants and animals play by very different rules. Most animals are screwed if they lose, say, their heart, but plants can survive incredible amounts of damage to all different parts of their bodies. The tradeoff for this is that plants can’t have parts that are too specialized. They can’t really have centralized brains, because then they would have a single vulnerable spot that they wouldn’t survive losing.

Because they can’t specialize too much, it’s hard for plants to develop things like locomotion. But not being able to walk doesn’t mean that plants don’t move. They just do it very… very… slowly.

The difference in plant and animal motion isn’t just in terms of speed. Animals move by lugging their entire bodies from place to place. Plants move by simply… growing. Getting larger. And larger.

“A flower does not think of competing to the flower next to it. It just blooms.” -Sensei Ogui

The above is a quote that I have seen passed around both facebook and tumblr for quite a while. It is a nice sentiment, and it is entirely wrong. The essentials of life for all plants are sunlight, water, and nutrients, and not one is limitless. No, not even sunlight; unless you grow enough to tower over all other plants in the area, you’ll be stuck struggling in the shade.

A lush and beautiful rainforest is also a savage struggle for resources among thousands of plants.

A lush and beautiful rainforest is also a savage battle for resources among thousands of plants.

Like animals, plants have also come up with crafty ways to compete with one another. One way is to simply kill the competition, or prevent it from ever growing. Many plants utilize a tactic called allelopathy, which essentially boils down to “let’s use chemicals to fuck with our neighbors.”

The black walnut tree is rather jealous over its root space, and will secrete a chemical called juglone into the soil. Not all plants are affected- some have evolved defenses- but for the ones that have not, juglone inhibits enzymes that are necessary for respiration. In other words, it stop plants from breathing.

But that isn’t even the most sinister effect allelopathy can bestow. Botanists are beginning to find that the secret to the success of many invasive plants lies in their aggressive allelopathy. Spotted knapweed, a European species that is now invasive to the US, utilizes a chemical called (-)-catechin to interfere with its neighbors. When another plant takes up (-)-catechin through its roots, the chemical causes a signalling cascade that actually turns off a a number of the genes in each cell it contacts. This means that the cell can no longer produce the proteins it needs to survive, and it dies within the hour.

Allelopathy is not always harmful to neighboring plants, however; in some cases, whether through mutually beneficial co-evolution or one plant sneakily taking advantage of another’s defenses, sometimes plants produce chemicals that help others grow. Sometimes a plant will produce a chemical that has a negative effect on one plant species, but a positive effect on another. It’s a tricky balance.

Some plants prefer a more medieval way of one-upping the competition than by using chemicals, however. These would be the climbing vine species, including the strangler figs. I’ll let Sir David describe what those do.

‘Strangler fig’ really is an apt name.

Perhaps plants very slowly fighting with other plants does not seem particularly frightening to you. But plants are not just affected by plant competitors- they are equally harassed and attacked by animal parasites and predators. A sheep or cow is about as vicious as it gets from a plant’s point of view. And, of course, they have means with which to fight back.

The most obvious of these means is poison- plants will produce phytotoxins (literally, plant toxins) that can cause anything from mild stomach upset or itchy skin all the way to asphyxiation or cardiac arrest. While this is good enough for us to leave certain plants alone permanently, there is a downside for the plants. Firstly, these chemicals are often complex and expensive to produce and build up in the cells; and secondly, animals may evolve resistance.

Some plants have come up with a slightly evil compromise.

I spoke before about how it doesn’t bother a plant so much to lose a few branches, roots, or leaves. So a bit of nibbling by a few herbivores will not cause a great deal of harm to a large bush. But when the number of leaves begins to dip dangerously low, this is another matter, and the plant may have ways to detect this and to take action- and more.

One example of this is oak trees. When caterpillars begin to eat oak leaves, the tree responds by ramping up the amounts of tannin and phenol in their tissue, making the stuff harder for caterpillars to ingest. In fact, the reason why herbivores have to eat so much plant matter- seriously, think about the amount of time a cow spends grazing, then sitting down and chewing cud- is because of this type of defense. As soon as the plant detects that it is being eaten, it turns on its less digestible compounds.

This can cause a normally harmless plant to become deadly. There is a famous case that occurred in the 1980s in which roughly 3,000 kudu inexplicably dropped dead in South African game reserves.

Imagine these, but dead. (Photo by)

Imagine these, but dead. (Photo by Paul Schaffner)

No predator attacked these kudu, and none of them looked sick; indeed, they seemed completely healthy. The culprit was, of course, a plant; acacia trees, which kudu can usually eat without repercussion. The problem was that a drought had killed many of the kudu’s other food sources, forcing them to feed almost exclusively from acacia trees. The trees did not like this, and when they started losing too many leaves, they went on the defensive.

Not only did the trees that were being attacked raise their tannin content to deadly levels (preventing the kudu from digesting any of the food that sat uselessly in their stomachs), but they also released an ethylene gas into the air to communicate with other acacias. When the other trees picked up the signal, they too increased their tannin levels, leading to mass murder of the hapless kudu.

In lieu of a nervous system or the ability to communicate with sound or movement, plants regularly speak to other plants- and animals- via chemicals like these. I am sure most of us are familiar with the phenomenon of sealing fruit in a bag to make it ripen faster. This is because fruit releases ethylene gas as it ripens that signals itself and the rest of the fruit on the tree to keep ripening. Apples and bananas are particularly strong ethylene producers, which is why slow ripening fruit like kiwis ripen faster if kept in close proximity to either of those.

Like the acacia, plants also produce ethylene when they are wounded to stimulate the healing process. Other plants in the area may “listen in” and ramp up their chemical defenses in preparation, whether or not they are the same species.

As I said before, plants can also use these chemicals to communicate with animals in rather surprising way. The tobacco hornworm is a familiar garden pest, and a voracious plant-eater. The tobacco plants that this insect preys on do not waste much time trying to poison their predator. Instead, they send out a cry for help via a volatile chemical compound. And who should answer but the lovely braconid wasp?

The wasp leaves the caterpillar with a few special, hungry friends. (Photo by)

The wasp leaves the caterpillar with a few special, hungry friends. (Photo source)

Yes, as a matter of fact, the plant calls the wasp over to kill the caterpillars. And this is not the only time that plants call for backup; it’s been documented many times, generally with insect predators. And the plants know who to call, too, because they can tell who’s eating them. Different types of herbivore saliva actually enact different defenses. This even extends as far as mechanical damage- if you rip a plant’s leaf without putting any of your saliva on it, the plant may not behave as though it’s being attacked. Those defensive compounds are expensive to produce, after all, and the plant doesn’t want to waste time over a freak accident.

The idea of a plant knowing who’s attacking it can seem ridiculous, considering that plants lack a brain or even a simple nervous system. But plants may know a hell of a lot more than we think they do; and it may be because we are too used to looking at things from an animal mindset. So a plant can’t afford to have a centralized organ for thinking, right? That may not mean it can’t think. It looks as though it definitely doesn’t mean that the plant can’t learn.

M. pudica, known as the “sensitive plant,” is one of the few plants that can display animal-like behavior. This plant actually responds to touch by closing its leaves. It does this not with muscles but via a system of pressure sensors that cause the cells in the leaves to lose their turgidity (firmness).

M. pudica responding to touch.

M. pudica responding to touch.

Some rather recent research on this plant came up with stunning results: the plant appeared capable of learning when a touch was not harmful. The scientists achieved this by dropping water on the plant’s leaves in both high and low light environments. In each case the plant seemed to figure out that it wasn’t worth closing its leaves for the water droplets in a matter of seconds; furthermore, it learned better in the high light condition than in the low light condition. In the same way, food-deprived animals will have more difficulty learning than well-fed animals.

M. pudica didn’t just remember about the water for a few seconds, though. Even a month later, it still appeared to remember that water droplet = not harmful. But when given another stimulus that it wasn’t familiar with, such as a vigorous shaking, the plant closed right up.

How does the plant store memory without a nervous system…? We just don’t know. But this is far from the first experiment to suggest that plants are capable of learning and memory. Other experiments have suggested that plants can remember being tilted sideways after spending a few days in a fridge (the plants respond to tilting by growing in the direction that they think is up).

Plants can actually navigate mazes much more efficiently than many animals can; they do this by growing towards a light or nutrient source. Plant roots ignore nutrient-poor soil patches but spend a lot of time feeding and getting hairier in nutrient-rich patches, just like a foraging animal. Plants will also move (grow) to avoid contact with other plants, and may even be able to tell when other plants are related to them. Some trees will pass on more carbon via fungal networks to their seedlings than other plants, and some plants avoid competing for soil nutrients with relatives but battle with strangers.

There is, in fact, a vast and terrifying body of research that suggests that not only may plants have a kind of intelligence, but it is a kind of intelligence that we are just beginning to tap in to. We are too used to associating ‘behavior’ with mechanical movement to really understand what plants are doing. Because they are behaving- slowly, yes, but with no less drive and intention than many animals. What we store in our brains might be spread out throughout the entire body of a plant, but it is still there, and it is capable of learning.

Imagine this: a movie monster that can basically regenerate any part of its body, that can change its chemical composition on a whim to become toxic, that can call in an army of wasps, for god’s sake. We live with these monsters. They are plants.

Previous creepy creatureFirst creepy creature!

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

Resources to Learn More

Documentaries

What Plants Talk About

In the Mind of Plants

Plants Behaving Badly (Parts One and Two)

Reading

Aspects of Plant Intelligence” by A. Trewavas (warning: it is very, very dense)

References

Allmann, S., & Baldwin, I. T. (2010). Insects betray themselves in nature to predators by rapid isomerization of green leaf volatiles. Science, 329(5995), 1075-1078.

Bais, H. P., Vepachedu, R., Gilroy, S., Callaway, R. M., & Vivanco, J. M. (2003). Allelopathy and exotic plant invasion: from molecules and genes to species interactions. Science, 301(5638), 1377-1380.

Cooper, S. M., & Owen-Smith, N. (1985). Condensed tannins deter feeding by browsing ruminants in a South African savanna. Oecologia, 67(1), 142-146.

Dudley, S. A., & File, A. L. (2007). Kin recognition in an annual plant. Biology Letters, 3(4), 435-438.

Gagliano, M., Renton, M., Depczynski, M., & Mancuso, S. (2014). Experience teaches plants to learn faster and forget slower in environments where it matters. Oecologia, 175(1), 63-72.

HOVEN, W. V. (1984). Tannins and digestibility in greater kudu. Canadian Journal of Animal Science, 64(5), 177-178.

Ishikawa, H., Hasenstein, K. H., & Evans, M. L. (1991). Computer-based video digitizer analysis of surface extension in maize roots. Planta, 183(3), 381-390.

Jose, S., & Gillespie, A. R. (1998). Allelopathy in black walnut (Juglans nigraL.) alley cropping. II. Effects of juglone on hydroponically grown corn (Zea maysL.) and soybean (Glycine maxL. Merr.) growth and physiology. Plant and soil, 203(2), 199-206.

Kessler, A., & Baldwin, I. T. (2001). Defensive function of herbivore-induced plant volatile emissions in nature. Science, 291(5511), 2141-2144.

Thellier, M., & Lüttge, U. (2013). Plant memory: a tentative model. Plant Biology, 15(1), 1-12.

Trewavas, A. (2003). Aspects of plant intelligence. Annals of Botany, 92(1), 1-20.

Creepy Creatures #4: The Real Ghost Shark

Yes, I already did one “ghost animal” this month, but since SyFy did a movie titled Ghost Shark, I couldn’t pass this up. Because there really is such a thing as a ghost shark.

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I haven’t seen Ghost Shark myself, but I’ve been made to understand that it is a modern masterpiece.

I’m not talking about the kind of ectoplasmic sharks that materialize out of slip’n’slides to eat small boys, though. The real ghost sharks are actually not sharks at all, but a group of creatures called a chimaeras.

When I say ‘chimaera’ I am not referring to the creature in Greek mythology, but rather a living group of fish related to sharks. These fellows represent some of the earliest body forms that jawed fishes ever took, right down to the large, placoid scales on the face. Most species also live in the deep ocean, which means that they get that extra dose of horror to their looks.

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Chimaera sp.

This is a 420 million year or more order of fish; far older than sharks, which they diverged from 400 million years ago. They were the earliest members of the class Chondrichthyes, the cartilaginous fishes.

Evolution_of_cartilaginous_fishes

The living members of Chondrichthyes are the chimaeras (Holocephali), the sharks (Galeomorphi and Squaliformes), and the rays (Batoidea).

Chimaeras are divided up into three families, the plough-nosed chimaeras (Callorhinchidae), the shortnose chimaeras (Chimaeridae), and the long-nosed chimaeras. (Rhinochimaeridae). That’s a lot of focus on the nose, and with good reason. Chimaeras can have some weird snouts, which makes the members of these three families instantly identifiable.

(Source: Fir0002/Flagstaffotos)

Callorhinchus milii, a plough-nosed chimaera.  (Source: Fir0002/Flagstaffotos)

Close up of Hydrolagus melanophasma, a shortnose chimaera, from Bustamante et al., 2012.

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Rhinochimaera pacifica, a long-nosed chimaera.

Here’s a rundown of bizarre physical features that chimaeras have.

Those noses are all covered in specialized sensory organs called electroreceptors that look like small pits. These are most obvious in the shortnose chimaeras, which are sometimes called rabbit or rat fish due to the rodentlike “spotted” appearance of their faces.

The smalleyed rabbitfish, Hydrolagus affinis, makes me uncomfortable.

The smalleyed rabbitfish, Hydrolagus affinis, makes me uncomfortable.

Like sharks, male chimaeras have claspers located on either side of their genital opening. However, they have a third, retractible clasper- on their head. This clasper doesn’t deposit sperm, but does help the male to hold the female’s pectoral fin during copulation.

claspers

Head and pelvic claspers of Callorhinchus milii. Those spikes are denticles, i.e., skin teeth. (Photo by Doug Perinne.)

Most chimaeras also have a venomous spine on their pectoral fin that is used in defense. I couldn’t find much about the potency of the venom, but some reports indicate that it creates painful wounds accompanied by swelling in humans.

Rhinochimaera africana is a good-looking dude.

Rhinochimaera africana has a prominent spine and wiggles that big nose around on the ocean floor to detect prey.

Adult chimaeras do not have teeth. The young ones do, but these fall out and are replaced by three pairs of large dental plates in adulthood. They use these to grind up hard-shelled crabs and mussels that they pull up from under the sand.

Dental plates of the spotted ratfish.

Beaklike dental plates in the skull of Hydrolagus colliei. (Source.)

These plates also give them lovely smiles.

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Callorhinchus milii again.

Their egg cases are weird-looking. I dunno what else to say about them.

capsule

 

And finally- and perhaps most intriguingly- chimaera skeletons contain traces of a third pair of limbs. Because of their placement in the fishes, this suggests that some of the earliest vertebrates may have had three pairs of limbs and later lost one. Neat!

R-pacific-banner

Chimaera: not super creepy, but definitely weird.

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

Videos

Ghost shark (Chimaera monstrosa)

Creatures of the Deep: Chimaera

Black Ghost Ratfish

Long-nosed Chimaera

Sources

Bustamante, C., Flores, H., Concha-Pérez, Y., Vargas-Caro, C., Lamilla, J., & Bennett, M. (2012). Primer registro de Hydrolagus melanophasma James, Ebert, Long & Didier, 2009 (Chondrichthyes, Chimaeriformes, Holocephali) en el Océano Pacífico suroriental. Latin american journal of aquatic research40(1), 236-242.

Dean, B. (1906). Chimaeroid fishes and their development (No. 32). Carnegie Institution of Washington.

Didier, D. A., Kemper, J. M., & Ebert, D. A. (2012). Phylogeny, biology, and classification of extant holocephalans. Biology of sharks and their relatives, 2nd edn. CRC Press, New York, 97-124.

Lund, R., & Grogan, E. D. (1997). Relationships of the Chimaeriformes and the basal radiation of the Chondrichthyes. Reviews in Fish Biology and Fisheries,7(1), 65-123.

Patterson, C. (1965). The phylogeny of the chimaeroids. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 101-219.

Previous Creepy Creature article: Blow Your Nose, Toad

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.)

Continue reading

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.”

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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.

Previous creepy creatureNext creepy creature

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

Videos

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.

Videos

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.