Sonorensis ARIZONA-SONORA DESERT MUSEUM 2014 REFLECTIONS Sonorensis ON OUR Desert Rivers ARIZONA-SONORA DESERT MUSEUM 2014 INTRODUCTION Linda M. Brewer ASDM Press Editor Volume 34, Number 1 Winter 2014 The Arizona-Sonora Desert Museum In the arid West, water wars and water negotiations are Co-founded in 1952 by both notorious and vitally consequential to people and Arthur N. Pack and William H. Carr wildlife. Water is tied to almost every resource we use or Craig Ivanyi reap—plumbing systems, crops, mineral extraction, electri- Executive Director cal generation, digital communications, etc.—as well as to Debra Colodner Director, Conservation Education trees and other vegetation that cleanse the air, organisms and Science Department that recycle dead organic matter into substrates for new Nancy Serensky Pierstorff Jay Brennan Tom life, and a full ecosystem that provides natural resources Production Manager for us and other living beings. Especially in arid lands, riv- Kim Franklin ers are veins of ecological gold, with an impact far beyond Managing Editor Contents the ground they cover. About half of all breeding birds in Linda Brewer the southwestern United States depend on the narrow Contributing Editor 1-2 Introduction ribbons that are riparian corridors, which represent just 1 Martina Clary Linda M. Brewer percent of the land. In the Sonoran Desert, 85 percent of Design and Production wildlife species depend on surface water or an associated Sonorensis is published as a benefit to the 3-8 The Colorado riparian habitat in some phase of their life cycle. Arizona-Sonora Desert Museum membership as Kerry Schwartz In this issue of Sonorensis, we tell the story of our a resource for furthering understanding of the rivers, because the story of rivers in the Sonoran Desert Sonoran Desert Region. 2021 N. Kinney Road, Tucson, Arizona 85743. ©2014 by the Arizona- 9-12 The River People on the Gila is largely a story of “rivers no more.” On the following Sonora Desert Museum, Inc. All rights reserved. No Henrietta Lopez & David DeJong, Ph.D. pages, scientists and historians tell us about the interplay material may be reproduced in whole or in part of people and water along the Colorado, Gila, Santa Cruz, without prior written permission by the publisher. 13-17 Requiem for the Santa Cruz River and Other Reflections and San Pedro River in Arizona, as well as the Yaqui, Altar, Visit us at www.desertmuseum.org Aros, Bavispe, and other Sonoran rivers—from personal Cover: A view from Rancho Los Fresnos, across a small Julio Betancourt, Ph.D. explorations, to water allocations, to restoration. reservoir, just south of the U.S.-Mexico border. This im- portant grassland habitat, with the headwaters to the Rio The need for new water policies and riparian res- San Pedro, is managed by Naturalia and The Nature Con- 18-23 Aquatic Architects at Work: The Return of Beaver to toration has become increasingly clear over the last servancy. It is largely ungrazed, and natural fire regimes San Pedro Riparian National Conservation Area few decades. In 2004, comparing historical and cur- are returning. Photo by Sky Jacobs. Marcia Radke rent data, The Nature Conservancy estimated that Back cover: Aerial view of the Colorado River during a 35% of Arizona’s natural perennial flowing rivers had pulse flow (upper left) snaking its way through the Delta into the upper estuary. The river’s locally known “kidney” 24-28 On the Rivers of Sonora, Mexico already been lost or altered. Of the many miles of area can be seen on the right. Photo by Francisco Zamora, Sky Jacobs once free-flowing water in the Colorado, Gila, Salt, Sonoran Institute with aerial support from LightHawk. and Verde Rivers more than 90% have been lost. And Thanks to all the photographers and organizations 29 Recommended Readings loss of surface flow has also been significant in the who contributed photos for this issue of Sonorensis. rivers of Sonora. In this issue of Sonorensis you will read Photos on this page, above: Rufous hummingbird about what that meant to the “River People,” the Akimel (Selasphorus rufus); Mexican garter snake (Thamnophis eques megalops). O’otham and Pee Posh along the Gila. Water is vital. LIKE FISH IN A RIVER Gila topminnow (Poeciliopsis occidentalis) Fish illustrations by Rachel Ivanyi. Perhaps the status of our fishes best illustrates the species have become common. Even populations of the taking their place. What kind of ecological cascade effect will state of our rivers. About three dozen native species, relatively large and aggressive Sinaloa cichlid (Cichlasoma result, we won’t know for some years to come. The same can most of the historical cast, are still hanging on in the beani), which had been thriving in Mexico, are now in de- be said for other introduced species in riparian corridors— Sonoran Desert Region, but their presence is tenuous— cline, largely due to introduced sunfishes and other non- species like tamarisk, a tree from Asia that has replaced signif- in part due to habitat loss, and in part because our riv- natives. The desert pupfish (Cyprinodon macularius) and icant stands of cottonwood-willow riparian forest favored by ers also now host at least twice as many introduced Sonoyta (or Quitobaquito) pupfish (C. eremus), true desert migratory birds, but which now is being used by some native or nonnative fish and amphibian species that compete stream dwellers, are still extant, but barely. (The Desert species. Some introduced species, however, may displace so with or prey on the natives. Museum currently maintains a small population of desert much biodiversity that the ecosystem becomes impoverished Modern technologies and policies that encouraged pupfish to assure a source for emergency reintroduction, for our children and grandchildren. dam building, diversions, and withdrawals from the un- but no longer actively breeds them.) Other aquatic and riparian obligate species are also derground aquifers have changed natural cycles of flow losing ground as our rivers lose water, including sala- and sedimentation, as well as water temperatures of riv- manders, frogs, and riparian reptiles. In fact, the Desert ers—changing the habitat to which native fish are adapt- OTHER AQUATIC AND RIPARIAN Museum has made great efforts to safeguard some of ed. Between habitat conversion and the introduction of OBLIGATE SPECIES—INCLUDING these species. For the last four years we have bred the game fish and other exotic species, native fish popula- Mexican gartersnake (Thamnophis eques), working in tions north of the international border have almost col- SALAMANDERS, FROGS, AND RIPARIAN collaboration with the U.S. Fish and Wildlife Service and lapsed, and pressures are increasing on them in Sonora REPTILES—ARE ALSO LOSING GROUND the Arizona Game and Fish Department to reintroduce as well. Many are federally listed as endangered. these now federally threatened animals once common AS OUR RIVERS LOSE WATER. About a dozen native fish species in the region are not along our major waterways. Also, for the last 20 years, yet listed as threatened or endangered. The longfin dace the Desert Museum has maintained a breeding program (Agosia chrysogaster) is still widespread; the desert sucker for the Tarahumara frog (Lithobates tarahumarae). (Pantosteus clarkii) is abundant in a more limited range, Once common in the upper Santa Cruz River system of This fall we released while in Sonora, the Sonoran Chub (Gila ditaenia) is rela- Arizona and Sonora, the Santa Cruz or Monkey Spring pupfish tively common. The beautiful shiner (Cyprinella formosa), (Cyprinodon arcuatus) is now extinct. More species are Yaqui sucker (Catostomus bernardini), and Yaqui catfish expected to follow suit, as intensive efforts to (Ictalurus pricei) are still present in Sonora in spite of introduce and/or bolster populations issues with water pollution in the Río Yaqui watershed, of natives—including razorback but they have been extirpated north of the border. sucker and loach minnow— Among the twenty-odd Arizona fish species that are have met with little federally listed as endangered or threatened are three long-lasting success. Colorado River fishes—the bonytail chub (Gila elegans), Introduced mos- Colorado pikeminnow (Ptychocheilus Lucius), and razor- quitofish, catfish, back sucker (Xyrauchen texanus). Also listed are the loach sunfish, shiners, minnow (Tiaroga cobitis) and Yaqui chub (Gila purpurea), bass, and non- which inhabit streams at somewhat higher elevations. native trouts and Many of those streams no longer flow regularly, and few minnows are already support large populations of native fishes, while nonnative well established and are Gila chub (Gila intermedia) 2014 winter | Sonorensis 1 EDI ASDM staff EDI Above, left to right: close up of North American beaver (Castor canadensis); Colorado River fishes – Top row, left to right, humpback chub (Gila cypha), bonytail chub (Gila elegans), razorback sucker (Xyrauchen texanus); center, woundfin (Plagopterus argentis- simus); bottom, Colorado pikeminnow (Ptychocheilus lucius). Illustration by Rachel Ivanyi; Tarahumara frog tadpoles (Lithobates tarahumarae) emerging from an egg mass at the Arizona-Sonora Desert Museum; white-nosed coati (Nasua narica). nearly 800 tadpoles and froglets. But the upshot is, rare yellow-billed cuckoo (Coccyzus americanus) and healthy riparian ecosystems and doing requisite science, riparian species need riparian habitat. southwestern willow flycatcher (Empidonax trailli)—as politics, and business in an attempt to preserve and well as around 85 mammal, 50 reptile and amphibian, restore them. We have learned that wise management RIPARIAN-AVIAN 14 fish species (6 of which are natives), and nearly 180 and a little water, applied in the right way, can have a species of butterflies. Ocelot and coati have traipsed large effect. As you are asked to vote on or otherwise CONNECTIONS these leafy corridors, not to mention bats that fly the consider water issues in the future, we hope you will cool air above. remember that a little water for nature can have tre- Migratory birds are dependent on green, flowering riparian Surface flows in the San Pedro River have been mendous returns.