cuban treefrog

WaterLine photo by Capt. Josh Olive

Cuban treefrogs are very cool animals — but if I could push a button and kill every one of them in Florida, I would.

CAPT. JOSH: I enjoyed your recent column (“Nature notes”), but I’m afraid I’m still in the “love it but can’t identify most of it” category. One thing that I always found interesting was the native vs. non-native labels we put on plants and animals. It appears anything or anyone that was here when the white man arrived is native, and any that arrived later are non-native. I guess you need some kind of definition, but who knows how long some of these “natives” were around.

— Al Petterson

Al, you’ve hit on one of the big head-scratchers of modern ecology: What species should be considered native to an area? The world has been changing for a very long time, and life has been changing along with it. Very few species have remained the same over the eons, and even those that have aren’t found in the places they once were because the climate undergoes perpetual change as well.

Perhaps the best way we have to delineate the two is whether they got to where they live on their own or were brought by people. Because so many species have been moved around by the Columbian Exchange (the movement of people back and forth between the Americas and the Old World, after Europeans learned there was land here and not the end of the world), we tend to think of it as a thing European people have done. Really, any people will do.

Honeybees are a great example. We’re not even sure where honeybees are native — might be Africa, might be southern Asia — but we do know for sure that people were moving them around long before Europe knew about the Americas. The same can be said of black rats, cattle and domestic cats. Identifying their native range is not really possible.

But we do know some places where they’re not native — to wit, the New World, since these animals have been associated with humans for thousands of years, but only on Old World continents.

Some animals and plants move themselves, with no help from us. Those that travel by air tend to be more mobile. Birds, sure — but also flying insects, plants that have fluffy wind-carried seeds, and even spiders. You did know that many spiders disperse from their nursery habitats via parachute, right? We’ll talk about it sometime.

Whether we translocate them or they utilize their own devices, species showing up in an area where they haven’t been before tends to be disruptive. The faster they colonize, the more disruptive they are. This is one of the major differences between natural range expansion and artificial: When humans are involved, it tends to happen faster.

This is also true when animals move because of situations humans have created. Coyotes were kept out of the eastern U.S. by wolves. Out west, coyotes and wolves coexisted because they each had their own niche: Wolves target big prey, coyotes hunt smaller animals and scavenge. In the the east, wolves lived more like coyotes, and so there was no room for the smaller canines.

But when we removed the eastern wolves on a large scale, that left a big empty ecological hole. Coyotes filled it very quickly, making it to the northeast by the 1940s and Florida by the 1970s. Despite moving in fast, their presence has been less disruptive to other wild animals because they replaced a predator that had been here previously. While people complain, ecological damage is minimal.

Contrast that with something like Burmese pythons. The problems they cause in the wild Florida environment are obvious and extreme. They are a worst-case scenario for what can happen when a non-native species is introduced and runs amok.

You wonder, when do they become native? The best answer we have right now: Eventually. Nature will eventually find a balance. Species that have been out-competed or otherwise harmed by non-natives will either find evolutionary means of adapting or they’ll die off. In the short term, it’s not pretty. In the long term — and I mean tens of thousands of years from now — it’ll be just fine, if we don’t move more species around.

But in the meantime, it’s a real shame to see what used to be disappearing in front of us. The natural order, the things that evolved together and matched pace with all the environmental changes around them, should be given a chance to survive. If that means shooting a few iguanas or burning Brazilian pepper trees, I’m OK with that.

This is not about human tribalism. I’m a Florida native, but that doesn’t mean I’m anti-snowbird. It’s not about valuing one species over another. Brazilian pepper is great — where it’s native. It’s about wanting to see biodiversity preserved, wanting to see animals and plants in the places they belong, wanting to explore ecosystems that function the way they did before we started making changes.

I know it’s probably too late — but a fella can dream, right?

Contact Capt. Josh Olive at 941-276-9657 or

Contact Capt. Josh Olive at 941-276-9657 or Publisher@


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