The Ecology of Pokémon
Pokémon are fictional creatures that inhabit a world similar to our own. Originally a series of video games, their creator, Satoshi Tajiri was an avid bug-collector growing up. As a result, the world of Pokémon holds many resemblances to our own. I am going to show you how some seemingly dry, theoretical ecology principles work quite well in this fantastical universe.
The world of Pokémon, like our own, has many different habitats. Image credit: Ken Lane via Flikr
Spearow vs Pidgey
Spearow and Pidgey are two “tiny bird” type Pokémon. They have similar biological characteristics, probably use the same kinds of habitat and eat the same food. Despite this, they very rarely occur in the same areas. This might seem a little odd on the surface of it, but we can make some solid ecologically-based guesses why.
In any ecosystem, there will be interactions between organisms. One type of interaction is interspecific (or interpoké) competition, where individuals of different species compete for resources (for example the best food or prime habitat). Think of limpets and barnacles competing for the best rock on the sea shore or the Pokémon Oddish and Bellsprout vying for the best patch of soil in which to plant themselves.
Competition for space on the rocky shore is very intense. Image credit: Jillyspoon via Flikr
The intensity of this competition often depends on how similar all the resource needs and habitat requirements of the different organisms are. If there is very little overlap, they won’t compete very much. However, when two species in the same area need many of the same resources to survive, it is a different story.
Intense competition between one or more species can lead to competitive exclusion. When there are too many individuals and not enough resources to go around, species with similar needs will begin to compete for those limited reserves.
Like two football teams wrestling over a ball (a limited resource on the footy field), there can only be one winner in competitive exclusion. However, the result is more severe than losing a match (even a grand final!). Over time, the species that is the stronger competitor will get more of the scarce supplies. They will grow better, produce relatively more offspring and ultimately take over. The poorer competitor gets relatively less, reproduces less and is edged out, eventually eliminated from the area.
How does this work with our two tiny bird Pokémon? Well, Spearow is very aggressive (its Japanese name literally translates to demon sparrow). Pidgey, on the other hand, is timid and generally prefers to run from confrontation. When there is not enough space or food for both Pokémon, it is likely that Spearow will attack and drive Pidgey away from the prime habitat. This is called interference competition. Over time, the Spearow do better than the Pidgey, take more of the resources and drive the Pidgey to local extinction.
An aggressive noisy miner about to get into it with an unsuspecting kookaburra. Image credit: Alex Proimos via Flikr.
So why doesn’t Spearow just take over everywhere and eliminate Pidgy completely? Obviously it is difficult for us to test this, but we can speculate.
Simply, it may be that Spearow have not reached all the areas where Pidgey are. There may be landscape features (such as large mountains) that prevent them getting there – this is what ecologists would call a dispersal barrier. However, considering that they can fly and are found in many different regions, it is likely that they are theoretically able to reach some of areas where they aren’t found.
Another plausible explanation is other interpoké interactions. Mankey, the pig monkey Pokemon, is hyper-aggressive and lives in trees, so there is some habitat overlap with Spearow and Pidgey. Mankey is also rarely found in the same areas as Spearow. In the areas where Pidgey and Spearow both occur, there are usually Mankey present. This suggests that the territorial Spearow and Mankey spend much of their energy in competition with each other, and leave the less boisterous Pidgey to itself, allowing it to get by.
Sometimes, being exceedingly territorial is not an advantage.
A standoff between a squirrel and a pigeon over some tasty peanuts. Image credit: fmpgoh via Flikr
The game of ecology
You might notice that I use words like “likely” a lot. Well, that’s intentional. It is often hard to prove that things are happening in the natural world. Also, there may not be one neat answer, but many combined reasons that are difficult to disentangle. Ecologists use many different lines of evidence to support one idea and not another. This is what makes ecology so fun – it’s like one big game of Cluedo.