What Makes a Species Rare?

book cover image
©. Island Press (book cover) and Eric Kilby (jaguar)

© Island Press (book cover) and Eric Kilby (jaguar)

Rarity is common, as odd as that may sound. But rarity occurs for different reasons. A species may be rare because it has a limited range, existing only in certain patches of habitat scattered across an area -- common in those locations but rare in the overall scheme of things. It may be rare because it has low populations, with individuals existing with just one here and another way over there, an uncommon sight anywhere one looks. Or a species may be rare because has extreme habitat specialization, living in only the most exact of locations with the most exact features in climate or food sources. It may be a species that has always been rare, or one that has been made to be rare because of outside forces, such as humans, acting upon it. Understanding both the how and why a species is rare, and keeping that in an historical context, is all part of conservation. And that is why exploring the concept of rarity as a whole is such interesting work.

In his newest book The Kingdom of Rarities, WWF Chief Scientist Eric Dinerstein explores the concept of rarity. Delving into ecosystems around the world and bringing readers along in rich prose, Dinerstein uses living examples of rare species to better understand what "rare" is and how the different types of "rare" affect potential conservation efforts.

The book is less a scientific lecture than a globe-trotting adventure as readers tag along with researchers working on projects involving rare species from birds of paradise to warblers, from jaguars to sakis monkeys, rhinos to golden langurs and more. Traveling from location to location with Dinerstein's descriptive prose, each project illuminates a new angle, a new facet to the complex concept of rarity and how a deeper understanding of a certain species type of rarity contributes to its conservation. As Dinerstein points out in his analysis, it is a better understanding of the entire concept of rarity that could unveil a host of new discoveries about the workings of nature.

"What if more biologists fanned out to study in depth not the common mongoose or the ubiquitous spotted deer but members of Chitwan's uncommon menagerie -- great hornbills, Gangetic dolphins, gharial crocodiles, sloth bears, and Indian bison? How might one's perspective on the natural world change? What novelties, complexities and even counterintuitive elements might emerge, and what adventures lay in store for the pursuer of these rarities?" writes Dinerstien.

Indeed, it is because rarity is so common that it is worth taking a closer look at its occurrence. Dinerstein points out that "as few as 25 percent of the world's species, such as robins, rats, and roaches, may account for 90 to 95 percent of all individuals on Earth." So, why not take a look at that other 75 percent, that majority of the rare? Consider what all may be discovered there and how it could utterly change how we approach conservation worldwide.

Looking closely at the work of researchers and scientists around the world, Dinerstein explores what it means for a species to be rare, and what understanding every detail of that rarity means for conservation efforts for that species and others with similar roles.

This is a truly fascinating and entertaining read -- and a quick one as it is rather hard to put down once you've started into it -- and will no doubt have you looking at rare species in a whole new light, questioning what we really know of them, what their ecological roles truly are, and what might be done to preserve them in a way that is meaningful to their role in the local and global ecosystem.