Egrets Two Ways: An Unsolved Mystery

A note to my friends and subscribers, this post is to let you know that I’ve started to publish my posts on Substack. The channel is The Attentive Naturalist

I’ll continue to put a preview on my blog so you can always keep in touch with what I’m writing about. It’s still free, so all you have to do is click the link and – I hope – subscribe. On this site, I’ll continue to post news and other related content.

Egrets Two Ways: An Unsolved Mystery – preview

As a graduate student at the University of Sydney, I became mildly obsessed with an odd question about Eastern Reef Egrets. Across the Pacific, these birds come in two color morphs: dark gray and pure white. The strange thing is that both morphs can hatch from the same nest, and nobody seems entirely sure why one color shows up where it does.

A friend and I spent several field seasons on Heron Island on Australia’s Great Barrier Reef trying to crack the puzzle. We counted birds, mapped nests, chased hypotheses, and even attempted to build a camera trap with whatever we could scrounge together on an island containing exactly one research station and one cocktail-slinging resort. Later, we saved our pocket money and went to Tahiti. I even carried the question to Hong Kong.

The answer remained stubbornly out of reach.

What we did discover was that white birds seemed closely associated with coral reefs, while dark birds turned up almost everywhere. Other researchers had reached much the same conclusion. The pattern was real. The explanation wasn’t.

Thirty years later, the mystery is still sitting there waiting for somebody with better tools, more data, and perhaps more patience than we had. Looking back, the story takes me from coral reefs and tidal creeks to ferries, conferences, and some of the best food I’ve ever eaten. It also reminds me that the world still contains questions that nobody has answered yet.

That’s one reason I still love natural history.

Read the full essay at The Attentive Naturalist on Substack.