by Whit Gibbons

September 8, 2003

What good is a rattlesnake? What good is a river clam? What good is a green pitcher plant?

People ask ecologists such questions many times each year. The question is seldom malicious. People really want to know what justification exists for protecting some creature or plant they are never likely to see and know little about.

The answer I give varies. Not because I keep changing my mind, but because the question has many acceptable answers. Most people want to understand why protection of endangered, rare, or seemingly insignificant species is important. Or why we should maintain species that can be dangerous or can restrict economic development. People want the justification to be relevant to their own lives. Because different people relate better to different answers, I try to pick the best answer for the audience.

I recently gave a talk to a group of deer hunters. As I was showing them a big canebrake rattlesnake, someone said, "What good is it?" That's a fair question for anyone to ask, but the man sounded a tad hostile, like I was the reason his hunting dog had been bitten on the face by a rattler in August. So I paused to consider the right response. Before I could speak, another hunter in the room looked at the man and said, "I can answer that. What good are you?" Two others chimed in with "Yeah. Yeah."

Indeed that is one response to the question of what "good" another species is. However, that's not how I usually answer the question, especially when the inquirer has a shotgun on the floor beside him. Nonetheless, in some situations and with some groups the way to respond is to point out that other species could ask the same question of us.

If I had responded, I might have pointed out an example from California in which local residents destroyed a den of hibernating rattlesnakes, only to have the community overrun by rats and mice that summer, presumably because a primary predator had been exterminated. The same case could be made for rat snakes, kingsnakes, or rattlesnakes in the East. Espousing the environmental value of a species in a tangible way works in some instances.

Another approach is to champion a species because of its research value. Thus some turtles can be used as biomonitors of unsuspected chemical contamination. A biomonitor is an organism with traits that reflect some feature of the environment. For example, in a lake contaminated by a pollutant such as arsenic, the turtles would incorporate low levels into their bodies and shells. Because some turtles move overland between lakes, sampling turtles anywhere throughout a region would likely reveal the presence of the contaminant. Once identified as present in a region, the arsenic's specific location could then be determined with further investigation.

Clams can also serve useful environmental roles both for research and as part of the aquatic food web. Clams are early indicators of environmental problems. If ecologists find that clams in a river are declining, we should look for serious water quality problems upstream. In addition, clams serve as food items for numerous fish and birds that most people place on their list of worthwhile species.
And, of course, in some situations one could resort to religious answers about humans serving as stewards of the earth and all its creatures, and ask whether we should be the ones passing judgment on other species that share the earth with us.

Answers to the question of "what good is it" are many, but I have two nonconfrontational favorites that cannot really be challenged by anybody. If I say I want to protect green pitcher plants "because I like them," who can argue with that? You may not like pitcher plants, but you can't tell me I don't or can't. And because I do, you must justify why you would get rid of something I like to have around.

But perhaps the best answer of all is, "we don't know yet." In other words, let's not denounce other species until we know for sure whether they have some value that we have yet to discover. They may have some trait that could be of direct utility to us. We just don't know yet.

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