The Island Scrub-Jay may teach us as much about evolution as Charles Darwin’s finches did over a century ago. Biologist Katie Langin, a graduate student at Colorado State University, has made a remarkable discovery about these birds—they’re splitting into two populations despite inhabiting the same island.
If you haven’t read about Langin’s work, Wired has an excellent piece on how these birds’ beaks are causing quite a stir among evolution experts (and Langin herself recently wrote about her work for Slate).
While we recommend you read each piece, here’s the takeaway: Langin spent months on Santa Cruz Island observing Island Scrub Jays, a close relative of the mainland’s Western Scrub-Jay. She realized that though she studied the birds assuming they were one species, the birds were divided into two groups with different beaks—birds that preferred oak trees tended to have shorter, stouter beaks, better for breaking into acorns, while the birds that preferred pine trees had longer, narrower beaks, better for prying pine nuts out of pinecones.
This is a pretty standard example of evolution, except one thing—the birds still live in the same place. Most of the examples of evolution involve some kind of geographic separation; for many years, Darwin and other evolutionary biologists believed physical separation was necessary for populations to diverge. Langin and other researchers are now looking into why these birds are pretty much ignoring each other (even though they could mate) and what this means for evolution theory.
But for Langin, this work presents not just a scientific curiosity but a legitimate conservation question.
“I think this research shows that we shouldn't just try to conserve Island Scrub-Jays, we should also try to conserve as much of the diversity from the species as possible,” she says.
To preserve the natural balance of Island Scrub-Jays, we’d have to change the way we see conservation: it may be as important to save diversity within a species as it is to ensure inpidual species’ survival. For example, if West Nile Virus, which has already proven deadly for other corvids, makes it to Santa Cruz, we couldn’t just vaccinate a bare minimum of the birds, but should vaccinate a representative sample from each habitat.
Langin’s article was published in the journal Evolution, and hopefully will bring a greater attention to the birds. “There are only around 2,300 individuals of this species, which is a really low number,” says Langin. “It's an incredibly rare bird.”
The bird gave itself some breathing room by adapting; now it’s up to us to help it go the rest of the way.