What We Talk About When We Talk About Invasives

Early on in the process of starting Invasive Eats, it became clear that a line in the sand would have to be drawn.

What exactly qualifies an invasive species?

At first, it seems like a simple question with a simple answer -- an animal that isn’t originally from here, but at some point was brought here, right?

Well, using that metric, a lot of animals that actually treasured and protected by state wildlife agencies would make the cut. In California alone, there are many examples.

Take, for instance, the wild turkey.

While there may be some that would contend this point by pointing to fossil records that suggest a turkey-like bird lived here tens of thousands of years ago, the fact of the matter is that wild turkeys (Meleagris gallopavo) aren’t native to California. In fact, a little more than a hundred years ago, there were a grand total of zero wild turkeys in California, and it wasn’t until the early 1960s that the state Department of Fish and Game, which was hoping to establish a huntable flock, was able to get populations to really take hold.

Given that the bird isn’t native, it’s pretty much unfathomable to think that it doesn’t have an impact on native species. The California quail and western grey squirrel share habitat and food sources with the turkeys, and some studies have suggested they’re being crowded out as turkeys gobble up their habitat.

Despite these, no where in California will you see wild turkeys listed as an invasive species. Instead, they’re managed as a public resource.  

Here, turkey is open to hunters during both a fall and spring season, each of which lasts roughly a month. During those two months, a hunter limiting out on birds, which would take a heck of a lot of luck or access to some sweet private land, would take home a maximum of five birds.

Two months of hunting. Five bird limit.

Even the most fervid PETA member would have to admit that’s a pretty restrictive season.

So, if simply being from somewhere else doesn’t make a species invasive, maybe their needs to be an established, documented negative impact on native species.

Well, it turns out that doesn’t always work either, and the striped bass (Morone saxatilis) is the perfect example.

A quick Google search will turn up a laundry list of evidence that suggests striped bass, which were brought to California from the east coast to establish a sport fishery, are decimating the native population of chinook salmon, which spawn in the Sacramento delta. The Department of Fish and Wildlife estimates that stripers consume between 25 and 50 percent of the smelt produced by the spring and winter salmon runs.

These bass are clearly impacting native fish, yet they’re managed almost as tightly as the salmon their eating. Size and bag limits are enforced and past attempts to lift these regulations have started massive battles with anglers and other interest groups.

As far as just about everyone is concerned, the striped bass is introduced, but not invasive.

But, where does that leave us?

The simple answer is that there’s really not a simple answer, but some ground rules about what is and what isn’t considered invasive are still needed.

So, here it is, my personal definition of what’s considered an invasive species:

  1. The species is non-native to the area it currently inhabits;
  2. There’s documented damage being done to the native ecosystem as a result of the species being present, and;
  3. The species isn’t currently being managed like a public resource (no bag limits, ect.)

Pretty simple, right?

Obviously, there’s a little grey area here and there. Every time I shell out $20 for a California pig tag I find myself questioning whether its really invasive, but, hey, the state’s got to make a buck where it can, I guess.

Now, if you’ve read this far, let me offer one more piece of guidance -- feel free to ignore everything I just wrote.

If you want to hammer stripers all year to make sure your kids will have salmon to fish for when they get old, then by all means, do it. And if you want to take the fight to wild turkeys to keep our quail populations healthy, do that too.

Just be sure not to let the “real” invasives slip by while you’re out there.