Endangered Species vs. Table 1.-- Endangered Habitats: A Concepti 2 R. Roy JOhnson , Lois T. Haight; and James M. Simpson3 Num! Date ext: l600s Abstract. - Although the great diversity within 1700s riparian ecosystems was recognized earlier, their extreme l800s productivity was not discovered until this decade. The 1900­ highest densities of nesting birds for North America have 1974 been reported from Southwest cottonwood riparian forests. 1 Complete loss of riverine habitat in the Southwest lowlands Direct could result in extirpation of 47 percent of the 166 2 species of birds which nest in this region. Indirect INTRODUCTION DISCUSSION Attemp Since 1600 more than 120 bird and mammal Extirpation The co species have become extinct while more than species bei 300 are now threatened (Fisher et al. 1969). The extirpation of wild animal species caused the In addition, dOI~ns of fish~s, am~hib1ans and has been a cause for concern for decades. to begin wo reptiles have become extinct or are endangered People only mildly interested in conservation wildlife in to say nothing of invertebrate species. Habi­ can bring to mind the examples of the Passenger of the "Red! tat disruption and destruction have been a Pigeon (Ectopistes migratorius - extinct 19l4), use the wore major cause of extinction. Only 24 percent of the Carolina Parakeet (Conuropsis carolinensis­ an unoffici. the birds and 25 percent of the mammals became extinct 19l4), the Dodo (Raphus cucullatus­ Service 197: extinct through natural causes. Of the 76 extinct 1681) and the Great Auk (Pinguinus gered speciE percent of the birds and 75 percent of the impennis - extinct 1844). Dates for extinction according te mammals which died from human related causes, are from Pettingill (1970) and Van Tyne and tion Act of well over half have been through indirect Berger (1971). An entire book has been written U.S. Federal means, such as introduction of exotic speices about the Passenger Pigeon (Schoerger 1955) and life ServiCE and habitat disruption (Fisher et al. 1969 and people are still trying to find out whether great depth IUCN Red Data Books issued periodically). or not the Ivory-billed Woodpecker (Campephilus grams. The principalis) is now extinct. Several recent and Wildlife In an attempt to reduce the numbers of books have been written appealing to citizens Colllllli t tee 00 species which will soon become extinct, se­ of the world to help save these rapidly National Aud veral steps have been taken. A major step diminishing species (Greenway 1958, Fisher et Fund} publis involves the formation of recovery teams, al. 1969, Prince Phillip and Fisher 1970, gered wildli comprised of authorities on a given species, Simon and Geroudet 1970, Tylinek and Ullrich governmental such as the Bald Eagle. The activities of 1972, and Ziswiler 1967). Information from and Wildlife these teams have apparently been beneficial the International Union for Conservation of garding enda in slowing down rates of loss in wildlife Nature and Natural Resources (I.U.C.N.) Red Fish Departm species. However, the efforts of recovery Data Books (issued periodically) presents a U.S. Forest teams cannot possibly prevent continued dismal picture (Table l). Service 1974 extirpation if we continue to disrupt habitat focusing on , through activities such as overgrazing, urban­ Wildlife (Ne, ization, "modern, clean" agricultural prac­ 1 Paper presented at the Symposium on 1972) or eve] tices, dam construction and channelization. Importance, Preservation and Management of the as the Pereg] Continued research is needed to provide answers Riparian Habitat, Tucson, Arizona, July 9, 1977. (Hickey 1969: to questions posed by management regarding 2 National Park Service, Grand Canyon jDendrocopos means through which critical wildlife habitat National Park Periodically, may be preserved. 3 Associate, Museum of Northern Arizona, species such Flagstaff Fish and Wile i Arize 1977 • Endan~ Arizona; 3 p. 68 1.--A history of species' extirpation. teams to address the problem of impending ex­ (adapted from I.U.C.N. Red Data tinction have been set up by the U.S. Fish and Books) Wildlife Service for many species of endan­ gered wildlife. For example, several avian species are now being raised by methods of Number of direct intervention such as egg manipulation (Zimmerman 1976). In addition, several 1 2 Date extinctions Direct Indirect agencies are now involved in establishing endangered plant lists. 1600s 21 86% 14% 1700s 36 84% 16% In addition to teams concerned with the 1800s 84 24% 76% protection of terrestrial wildlife, such as 1900­ the Peregrine Falcon and Southern Bald 1974 85 28% 72% Eagle, other recovery teams have been organ­ ized to focus on one or moSe fish species. 1 Direct = Hunting for food or commercial Recently, however (Johnson-) the U.S. Fish causes. and Wildlife Service has designated teams 2 Indirect - Habitat disruption, introduction which focus on river systems instead of of exotics, etc. individual species, e.g. the Colorado River Fishes Recovery Team. This approach has been advocated for years by many of us who Attempts to Prevent Extinctions have seen the wholesale extermination of species in certain areas as a result of The concern over the increasing numbers of habitat destruction. Nowhere is this chain species being exterminated in the United States of destruction more certain than in riverine es caused the U.S. Fish and Wildlife Service ecosystems. This has long been recognized to begin work on classification of "threatened" by ichthyologists such as Deacon and Minck1ey tion wildlife in the early 1960's. The 1st edition (1974), Holden and Stalnaker (1975), Minck1ey senger of the "Redbook" was issued in July 1966. We and Deacon (1968) and Sigler and Miller (1963). 1914), use the words "threatened" and "endangered" in ensis­ an unofficial sense (see U.S. Fish and Wildlife us- Service 1973 for official definition). Endan­ Glen Canyon Dam: An Example s gered species are assigned in the United States nction according to the Endangered Species Conserva­ The construction of Glen Canyon Dam on nd tion Act of 1969 and listed periodically in the the Colorado River above Grand Canyon is an Litten U.S. Federal Register by the U.S. Fish and Wild­ outstanding example of habitat modification. 5) and life Service. It is not our intent to go into The effect on the aquatic ecosystem has been .er great depth regarding endangered speices pro­ devastating. The original heavy silt burden philus grams. The forementioned I.U.C.N., U.S. Fish which rendered the Colorado River "too thick ent and Wildlife Service and others (e.g. American to drink and too thin to plow" is dropped in .zens Committee on International Wildlife Protection, Lake Powell before the water enters Grand National Audubon Society and World Wildlife Canyon. The river waters are now clear. The r et Fund) publish periodic information on endan­ reddish color for which the Colorado was named gered wildlife (e.g. Arbib 1976). Other can be seen only after flooding from tributaries ich governmental agencies besides the U.S. Fish which enter below the dam. This has created rom and Wildlife Service publish information re­ an entirely new riverine ecosystem (Carothers of garding endangered w!ld1ife (Arizona Game and et a1. in press, Dolan et a1. 1974 and in .ed Fish Department 1977-, Behnke and Zarn 1976, press, Johnson and Martin 1976,and Laursen a U.S. Forest Service 1975, U.S. National Park and Si1verston 1976). The management impli­ Service 1974). Symposia are held periodically cations are staggering. On one hand, a new focusing on general problems of endangered riparian ecosystem has developed, protected wildlife (New Mexico Game and Fish Department from the scouring and siltation of pre-dam on 1972) or even devoted to a single species such floods. On the other hand this white water f the as the Peregrine Falcon (Falco peregrinus) river has been converted from a stream which , 1977. (Hickey 1969) or the Red-cockaded Woodpecker was warm in the summer and cold in the winter .yon 1Dendrocopos borealis) (Thompson 1971). to a relatively constant 9-10°C (48-50°F) Periodically, reports are issued on endangered along most of its length. The only insect izona, species such as the Southern Bald Eagle (U.S. family recorded using these cold waters are Fish and Wildlife Service 1976). Recovery Chironomid midges (Stevens 1976) while the i Arizona Game and Fish Department. ~ Johnson, J. Paper presented at New 1977. Endangered and threatened species in l1exico-Arizona section meeting, the Wildlife Arizona; 3 p. memo Society, Farmington, N.M., Feb 5, 1977. 69 small crustacean, Gammarus lucustris, abounds. vention of the use of streams for waste disposal The cold, clear water is conducive to the is gradually becoming an accepted philosophy. rapid growth of exotic species such as rain­ Conversely, industrial, domestic and irrigation bow trout, which commonly reach lengths of demands for water for a growing population con­ more than 2 feet and weigh over 5 pounds tinue to escalate. (personal observation). While exotic fish flourish, our native species are declining. In the 277 miles of the Colorado River in Major Causes of Habitat Loss Grand Canyon National Park several species listed in Fishes of Arizona (W. Minckley The impact of dams on aquatic ecosystems 1973 and pers. comm.) occur either in low has long been understood by biologists even if numbers, or cannot be found at all, e.g. the ignored by dam builders and water users. The Humpback Chub (Gila ~), Bonytail Chub (Q. area above the dam is converted into a lake, elegans), Colorado Squawfish (Ptychocheilus rapidly filling with sediment. The area below lucius) and Razorback Sucker (Xyrauchen the dam too commonly becomes a dry stream bed, texanus) (Johnson 1977, C. Minckley and Blinn as is the situation with most of the Salt and 1976, Miller 19752, and Suttkus et al.