On the Origin of Species: Woobat
So, let's talk about Woobat. Woobat is a flying ball of white fluff with black, bat-like wings and an enormous heart-shaped nose. It's an improbable-looking thing, but it's based on a real animal. In fact, it's based on the cutest animal you'll see today. Now, I know that in the past I've argued for the cuteness of hyenas, cicadas and sea slugs, but trust me with this one.
Woobat would seem to be based primarily on Ectophylla alba, the Honduran white bat. The first thing to say about this animal, because it might not be immediately obvious from pictures, is that it's small. Really very small indeed: the average length of an adult is about four centimeters, with a weight of around five grams. Just like Woobat, these animals have round, white, fluffy bodies, black wings and big, fleshy noses. Though Woobat's design has exaggerated some of these features, they're not nearly as exaggerated as you might have guessed.
Honduran white bats live in the lowland rainforests of Central America, their habitat including parts of Honduras, Costa Rica, Nicaragua and Panama. They're limited to these areas because they depend on a particular genus of plants, Heliconia, for shelter. They're one of a small number of bat species that make 'tents' for themselves, by chewing along the center vein of a Heliconia leaf and causing it to fold downwards into an inverted V-shape. Multiple bats can then roost beneath the leaf during the day, sheltered from rain, sunlight and predators, and then emerge at night to look for food. Although the Honduran white bat is considered to be part of the Microchiroptera or microbat superorder, which consists mainly of insectivores, Honduran white bats are strict vegetarians, feeding mostly on fruit.
The flat, oddly-shaped nose is a characteristic of many bats, and I suspect that another species, the Heart-nosed Bat (Cardioderma cor) may have been part of Woobat's inspiration. Despite the name, however, the heart-nosed bat's nose isn't any more heart-shaped than that of the Honduran white bat, at least to my eyes. The noses are brought up in Woobat's Pokédex data, with one entry stating: "It emits ultrasonic waves from its nose to learn about its surroundings". Surprisingly, this is another fact that's taken directly from nature.
Now, the fact that most bats use echolocation (the bouncing of sound waves off nearby objects to aid in navigation) is quite well known, but what's less commonly known is the role of the nose in the process. In many species of echolocating bats, the sound waves actually come from the nose, which is shaped in such a way as to amplify and modulate the noise. Why the nose, and not the mouth? Well, some bats, especially the insectivores, will want to eat while they're in flight, and this system allows them to echolocate and eat at the same time.
I chose to focus on Woobat and not its evolution, Swoobat, because Swoobat's design elements seem to come from a wide variety of bats, rather than a particular species (though it is rather closer to the heart-nosed bat in appearance than its pre-evolution). However, I do want to mention one aspect of Swoobat, which comes once again from the Pokédex: "Anyone who comes into contact with the ultrasonic waves emitted by a courting male experiences a positive mood shift". When I read this, I thought it would be a good opportunity to discuss how bats use ultrasonic waves for courtship. Imagine my surprise, then, when I set out to research the topic and found that there isn't really much firm evidence that ultrasonic waves play a role in courtship rituals at all. That's not to say that it doesn't happen, however... it just seems that there hasn't been much research into the matter, which means that we don't yet know anything about it.
It does seem reasonable that bats would use their ultrasonic abilities to call for mates, and indeed we do see this behaviour in moths and some species of frogs. I was only able to find one study dealing with bats, which looked at the big brown bat (Eptesicus fuscus). It concluded that ultrasonic vocalizations appeared to determine which females were more likely to attract males, but that the opposite was not true. It seems surprising that there haven't been more studies of this type, and I hope that this area of research gets explored more thoroughly in the future.
Perhaps we shouldn't worry too much about how the Honduran white bat goes about attracting a mate, however, because what we can say for sure is that it certainly works. When you see a group of bats clustered together beneath a leaf, bear in mind that the group actually consists of one male and a 'harem' of females. Like all species of tent-making bats, Honduran white bats are believed to be polygynous, living in groups that consist of a male and numerous females. These harems are no casual arrangement, either: they've been observed to stay together for many years, possibly even for life. The Honduran white bat, much like the Pokémon it inspired, really is a true romantic at heart.