Biodiversity – Costa Rica v. The World

White-throated capuchin in a mangrove.

Costa Rica is known around the world for its biodiversity.  It’s one of the main reasons why people travel so far to visit the country.  We like to visit areas with amazing natural beauty, especially if there is an opportunity to see interesting plants and animals.  Biodiversity has value to people just because we know that it exists, separate from the economic benefits we get from the products and services the natural world provides.

But just how many species are there in Costa Rica compared with the rest of the world?  This is not an easy question to answer.  First of all, we don’t know how many species there are on the Earth (or Costa Rica).  One recent estimate of the number of terrestrial species on the planet is 8.7 million … but this is just an estimate, we have only cataloged and named 1.2 million.  This means that something like 80-90% of the species that we think exist on the planet aren’t yet discovered, so any list of species is incomplete just because we don’t know enough.

One common statement that you’ll  find about the biodiversity of Costa Rica goes something like this:

Although Costa Rica represents 0.03% of the world’s landmass, it houses around 4% of the world’s species.

That’s impressive, right?  I’m working on tracking down some of the original references to get numbers to back this up … but it’s not easy.  Some groups of organisms are well studied, so we are more confident of their numbers.  Birds are a good example.  We know a lot about birds because they are easy to see and a lot of people spend a lot of time looking for them.  There are around 850 named species of birds in Costa Rica, which represents around 8.5% of the world’s named species.  Bats are another good example — of the world’s bats, about 10% are found in Costa Rica.  Insects, on the other hand, are much harder to get a handle on, but they are an incredibly important part of the equation.  Of the 500,000 species that are estimated to exist in Costa Rica, something like 300,000 are insects.

A dung beetle, doing what it does ....

Costa Rica sits within the Meso-American biodiversity hotspot region, which includes the landscape from southern Mexico to Panama.  “Biodiversity hotspots” are areas of the planet that house much more of the biodiversity than most others.  First conceived in order to identify and prioritize conservation areas, biodiversity hotspots are defined as regions of the Earth that have a high number of endemic plants AND that have less than 30% of its original vegetation.  Twenty-five hotspots have been identified on the Earth, and these areas house around 60% of the world’s species.  Conservation International has grabbed onto this concept and advocates for conservation within these areas.

Of course, where there are more species there is also a greater potential of losing them.  Hotspots, in particular, are in danger of losing species just because of how they are defined: by endemic species and by the loss of their original vegetation.  Costa Rica, as a country, has done much better than average in this regard by preserving large areas of land (around 25% of total) and encouraging the protection of species and habitats through environmental legislation.  But even this is not enough to ensure that species will not continue to go extinct.

Since we don’t know exactly how many species there are on the planet, we can’t possibly know exactly how many are going extinct.  From one perspective, I find this incredibly depressing.  If we don’t know how many species we are losing, how can we possibly expect to make the best decisions about how to minimize the large-scale extinction that we are currently making our way through?  But from another perspective, it motivates me to step up and make an impact.  We have an amazing opportunity to learn a lot more about the world we live in and make a significant contribution to what our future Earth will look like.