Animal Myths: LAND

Welcome back to our Animal Myth series, where we strive to debunk common animal misconceptions. In this post, we focus on animals that share our most familiar habitat: land.

Note: If you haven’t already, check out the other Animal Myths posts on creatures of the sky and sea!

1. Camels use their humps to store water

Camel with a depleted and a full hump. Photo by Eric Chan.

While this “fact” isn’t entirely true, it isn’t entirely false either. But, if you’re imagining a camel with an (ironically-named) camelback strapped to their body, this is the heart of the myth. The hump of a camel is not filled with water – it’s filled with fat. However, these fat stores do serve as a source of hydration and nutrition for camels when food is scarce. When these stores deplete, the hump becomes rather flimsy and floppy, but returns to its full glory after a good meal and some rest [1]. In addition to their humps, camels have a suite of adaptations that allow them to thrive in dry, hot deserts. First, when camels drink, they drink A LOT – like, 30 gallons of water in 15 minutes! All of this water is stored in their bloodstream with the help of their unique red-blood cells. Camels are also able to regulate their sweat production, body temperature, and urine production to conserve water and handle the heat [2].

2. Humans only use 10% of their brain

Scan of brain activity. Image from Reigh LeBlanc.

Though origination of this myth is largely unknown (and is sometimes attributed to Einstein), it is so wide-spread that it even has its own Wikipedia article! However, it is wholly false. In truth, we use 100% of our brains throughout an average day [1]. At any point, different regions of the brain may be more or less active, but there is not typically a region of the brain that is completely nonfunctional [2]. A portion of the brain’s function is to control automatic processes such as your heartbeat, blinking, and breathing. However, even when you’re asleep, there is more brain activity than just in the brain stem (which controls involuntary functions). Every area of the brain serves a different, important purpose –processing your senses, critical thinking, muscle control, movement, and memory, to name a few. Additionally, if 90% of our brain was not in use, brain injuries would not be such a serious issue. Instead, we know that even small injuries to the brain can have detrimental and lasting impacts!

[2] Beyerstein, B. (1999). Whence Cometh the Myth that We Only Use 10% of Our Brains? Della Sala, Sergio (red.). Mind Myths. Exploring Popular Assumptions About the Mind and the Brain.

3. Lemmings drown themselves when their populations are too big

Lemming image found here.

While not the origin, the widespread propagation of this myth can largely be attributed to Disney. The Academy Award-winning 1958 Disney documentary, White Wilderness, contains staged footage of lemmings jumping from cliffs to their watery deaths (more about this strange film here). Lemmings – small, vole-like rodents – do not commit mass suicide, nor do they practice intentional population control; this is not how evolution works. But, when you consider natural lemming behaviors, it’s easy to see how this myth started. Lemming populations are cyclical – some years the population booms, some years it crashes. Populations of lemmings can grow so quickly that in the 17th century it was believed they fell from the sky! Additionally, if food supplies are depleted in their habitat, lemmings will undergo mass dispersal: the movement of many individuals to a new area. This dispersal sometimes does occur in response to a population upswing, as large populations will lead to faster nutrient depletion. Occasionally, lemmings encounter water edges during this mass dispersal. But…lemmings can swim. While it’s not uncommon for a few to drown while crossing water en masse, most lemmings make it across just fine [1].

4. Dogs see in black and white

The same image as seen by a human (left) and dog (right). Image from Cook.

To debunk this common myth, we once again need to look at the sensory system of the animal in question. But first, it may be helpful to understand the physiology of human sight. Our eyes contain cells that help us detect light and color: rods and cones, respectively. While rods help us distinguish light levels and contrast, the type and number of cones an organism possesses inform what colors that organism can detect. Most humans are trichromatic; we have three cones which peak in the red, blue, and green wavelengths. In comparison, dogs (as well as cats, horses, and some colorblind humans) have only two cones. These so-called “dichromats” often have trouble distinguishing between reds and greens. Importantly though, this also tells us that dogs do see in color – they just see it differently than us (see the figure above). Additionally, there is a lot more to vision than just color detection; you can learn more about visual resolution and acuity here.

5. Daddy long legs are the most venomous spider, but their fangs can’t puncture skin

“Daddy long legs:” a crane fly, Tipula sp. (left), a house spider, Pholcus phalangioides (center), and a harvestman, Metaphalangium sp. (right). Image from the Burke Museum.

Before diving into the heart of this myth, we first need to cover some terminology. “Daddy long-leg” is, interestingly, a regional term and can refer to one of three species (see above). The first part of this myth is immediately debunked depending on which species you’re considering, as only one of the three species is actually a spider: the house spider in the center. Harvestman (right) are arachnids (but not spiders), and crane flies (left) aren’t arachnids at all [1]! Additionally, neither crane flies nor harvestmen have venom – so they definitely aren’t the most venomous – nor do they have fangs! So what about the spider? Well, while they do possess both venom glands and fangs, there is no evidence that their venom is harmful to humans [2]. In fact, it is speculated that their venom may be unusually weak [3].

6. Ostriches bury their heads in the sand

This may be the most ancient myth we’re tackling! The first written record of this myth comes from Pliny the Elder (the Roman writer, not the beer), who suggested ostriches shove their heads in a bush when frightened and, “imagine…that the whole of their body is concealed” [1]. In truth, a startled ostrich will drop low to the ground, perhaps concealing itself behind a bush, and lay its head and neck on the ground [2]. This form of predator avoidance is effective, as it will minimize the ostrich’s chance of being seen. In contrast, an ostrich hiding only its head, employing “if I can’t see you, you can’t see me” logic, would still be quite visible to a predator. At some point, the myth switched from a bush to the sand, possibly as we observed more natural ostrich behaviors. For instance, while they can’t fly, ostriches are still birds and build a nest for their eggs. An ostrich nest is typically just a shallow hole in the ground, in which ostriches will lay and tend to their eggs, often pushing the eggs around with their beaks [3]. Perhaps this natural nesting behavior that involved head movements in the ground contributes to the continuation of this historic myth!

An ostrich tending to its nest in the ground.

Stay tuned for our last installment of Animal Myths, where we’ll dive into misconceptions about aquatic animals…

Ryane Logsdon in a member of the Animal Behavior Graduate Group. Her Ph.D. research aims to understand the influences of social and structural environments on courtship behavior in the Greater sage-grouse.

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  1. Pingback: Animal Myths: AIR

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