God in His wisdom made the fly And then forgot to tell us why.
-- Ogden Nash(1)
The protagonist in our story has six legs, is one inch long, and dies two weeks after it emerges from the ground. To the untrained eye, the Delhi Sands Flower-Loving Fly looks like, well, a big fly. Entomologists know better. This particular fly can hover like a hummingbird as it uses its long tubular nose to extract nectar from flowers. It can only live in particular fine soils -- the Delhi sands that appear in patches over a forty square mile stretch from Colton to Ontario, California. Today only a few hundred Delhi Sands Flower-Loving Flies survive in less than a dozen such patches located in an eight-mile radius split by I-10 and the Southern Pacific railroad tracks. Therein lies the Fly's claim to fame. Of the 80,000 known species of flies, the Delhi Sands Flower-Loving Fly is the only one to be listed as endangered under the Endangered Species Act,(2) and it is the only fly to divide the D.C. Circuit three ways concerning the meaning of the Commerce Clause.(3) choices raise a number of questions about the necessary relationship to interstate commerce. These questions produce conflicting answers, so the fate of the ESA's protection of the Fly's habitat depends on which is the right question to ask.
The Relationship Between the Fly and Interstate Commerce
The Actual Relationship Between the Fly and Interstate Commerce
Suffice it to say that the Fly does not offer a noticeable contribution to the economy of San Bernardino County or anywhere else. The Fly does not possess any known medical value. Tourists do not flock to see it. People do not eat it. Scientists have searched in vain for any contributions that the Fly makes to human life. It is not the subject of the popular imagination or a key performer in the popular culture.(27)
Nonetheless, the government bravely suggested that the Fly was active in interstate commerce, and the district court agreed. That relationship was revealed by (1) the exhibition of the Fly in at least three museums located outside of California, (2) at least two instances where people outside of California purchased a Fly via an insect sales catalog, (3) people who traveled to California to observe and study the Fly, and (4) articles about the Fly in scientific journals.(28) These are relationships to interstate commerce, but it is hard to maintain that they are the substantial relationships needed to invoke the Commerce Clause. Nor would other hypothetical -- but easily manufactured -- relationships suffice. The fact that I have plane tickets in hand to travel to California to visit the Fly may get me standing to object to any action that would harm the Fly,(29) but it will not trigger the power of Congress to invoke the Commerce Clause. Likewise, the availability of souvenirs depicting a seemingly obscure endangered species should not tie the species to interstate commerce because the ability to market products featuring a species may actually be enhanced if the species becomes extinct. Perhaps the most telling criticism of the adequacy of these relationships is that Judge Wald abandoned any contention that the Fly itself actually affects interstate commerce, despite her various other theories supporting the reach of the ESA's takings provision in this case.
It is unlikely, therefore, that the Fly can be shown to have an actual, substantial relationship with interstate commerce. But even if one determined that the evidence that the district court recited was sufficient, that would not resolve the constitutionality of the ESA in other cases. Other endangered species are harder to connect to interstate commerce than the Fly. The primary habitat of the recently listed Peck's cave amphipod is "a zone of permanent darkness" in a single underground aquifer in Texas.(30) The Cowhead Lake tui chub is a three inch minnow with no known commercial or recreational value that is found only in one three mile stretch of water in rural northern California.(31) The Deseret milk-vetch is even more reclusive, thought to be extinct for seventy-two years prior to its rediscovery on one 300-acre site in central Utah.(32) There are many such species that survive only in one state, that were long thought to be extinct, that are quite similar in function to other species, or for which there is no discernible commerce -- and there are some species that possess all of those characteristics. Indeed, the litigation over the Fly itself has already prompted landowners to claim that the federal government lacks the authority to list the Illinois cave amphipod because that species does not affect interstate commerce.(33) So even if one would strain to identify a connection between the Fly and interstate commerce, someday another case involving an even more obscure species would raise the same questions.
The Potential Relationship Between the Fly and Interstate Commerce
Judge Wald speculated that "it is not beyond the realm of possibility" that the Fly could contribute to the pollination of America's farms.(34) Likewise, one would expect that scientists could surely learn something from the Fly, especially since the Delhi Sands Flower-Loving Fly is the last subspecies of its species, and one of only a few left in its zoological family.(35) The decision to protect the Fly also recognizes the importance of the continuing availability of a wide variety of species to interstate commerce,(36) a variety that demands a large number of species but no one species in particular. Judge Wald wrote that "diminishing a natural resource that could otherwise be used for present and future commercial purposes" ties all species, including the Fly, to interstate commerce.(37) More sarcastically, Judge Sentelle's concern about the consequences that would follow if a Fly splattered on the windshield of a car would become even greater if the car was traveling across state lines.(38)
Each of these arguments relies upon the effect that the Fly could have on interstate commerce. There is no evidence to support any of the claims at this time. Thus Judge Henderson objected that "it is possible that no endangered species will ever realize an uncertain potential medical or economic value."(39) But it would be presumptuous to contend that we know everything there is to know about the Fly and its relationship to natural processes or human activities. Indeed, the unknown benefits of a species are routinely cited as a reason for protecting the species, even when we have not identified those benefits to date.(40) Thus it is possible that the Fly could yield valuable services to human society once we manage to discover them. Meanwhile, our inability to know whether the Fly can be valuable or not makes us unable to know whether the Fly will substantially affect interstate commerce or not.
The Relationship Between Endangered Species and Interstate Commerce
The Relationship Between Endangered Species Generally and Interstate Commerce
There is a substantial relationship between endangered species writ large and interstate commerce. Congress stated that the ESA is necessary because "species of fish, wildlife, and plants are of esthetic, ecological, educational, historical, recreational, and scientific value to the Nation and its people.(41) Consider each of these values. The esthetic and recreational worth of endangered species is demonstrated by the millions of people who travel to see whales, bald eagles, grizzly bears, whooping cranes, and other rare animals throughout the country. Such ecotourism accounts for billions of dollars annually in the surrounding communities.(42) The ecological value of endangered species refers to the role that animals and plants play in promoting air and water quality, regulating the climate, removing unwanted pests, creating and protecting soil, controlling floods and droughts, pollinating crops, protecting the earth from ultraviolet rays, and dispersing seeds and nutrients.(43) Endangered species serve an educational and scientific function by teaching us about ourselves and the world in which we live. Historical benefits come from bald eagles and other species that have a special place in our national consciousness.(44)
There are other benefits that Congress did not mention in its purpose statement for the ESA. Most importantly, endangered plants and animals may be an important source of drugs and other medical treatments.(45) Several plants are being studied in an effort to find a cure for AIDS.(46) Likewise, the nutritional value of endangered species is seen in the nearly billion dollars that genes from wild plant species add to agricultural production in the United States each year.(47)
Each of these reasons for protecting endangered species is easily linked to interstate commerce. Other reasons, especially the moral and religious arguments for the preservation of endangered species, are less readily tied to interstate commerce.(48) Likewise, many endangered species are found in more than one state, though why that serves to justify federal regulation under the Commerce Clause has never been clear to me.(49) But even without the moral arguments or the movement of the species themselves, the utilitarian values cited by Congress when it enacted the ESA provide ample grounds for concluding that the protection of endangered species bears a substantial relation to interstate commerce.
The Relationship Between Each Endangered Species and Interstate Commerce
The Commerce Clause would plainly be inadequate as a constitutional basis for the ESA if each protected species were required to possess an actual medicinal, nutritional, or other specific value. The countless benefits provided by endangered species as a class do not mean that every endangered species offers utilitarian benefits. Most species are of no nutritional value to humans. Efforts to identify plants and animals with medicinal uses have identified...