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vol. 34, no. 1
<br />vrrently underway and
<br />s Rept, 19.1-19.2.
<br />r the ringed salamander,
<br />is Education Ser., Univ.
<br />!oma annulatum. SSAR
<br />unanders. Amer. Mus.
<br />salamander, Ambystoma
<br />Vat., 84:77-89.
<br />nd a list of batrachians
<br />21:85-89.
<br />alamander, Ambystoma
<br />a, (SET, WEM) Dept.
<br />Game and Fish Comm.,
<br />~~lueller ~ .~ ~~~ rn~~ ~ ,~~
<br />~q~ ~u~ll~ lg~
<br />March 1989 Notes 147 ~ I
<br />the lizard in the ground initially, then returned a few minutes later, and transferred the lizard to a
<br />Lyonothamnus.
<br />The dry, loose, exfoliating bark of Lyonothamnus forms innumerable pockets where small objects
<br />can be tucked and completely hidden from view. Although caching of food by animals in Lyonothamnus
<br />has not been reported previously, its discovery may have some paleo-ecological significance. Millions
<br />of years ago, Lyonothamnus lived on the California mainland and in Nevada, Washington, and Oregon
<br />(Wolfe, 1964; Raven and Axelrod, 1978; Junak, 1987). At that time, it was part of the great Madro-
<br />Tertiary Geoflora (Raven and Axelrod, 1978). Today, this tree survives only on four islands off the
<br />coast of southern California (Santa Rosa, Santa Cruz, Santa Catalina, and San Clemente). Perhaps
<br />in the Tertiary woodlands of western North America, jays and other animals living in association with
<br />Lyonothamnus also stored food in its bazk, just as the island jay does today.
<br />My research on Santa Cruz Island was made possible by C. Stanton, L. Laughrin, S. Clarke, the
<br />Santa Cruz Island Company, the Marine Science Institute of the University of California, Santa
<br />Barbara, and the U.S. Navy. L. Laughrin assisted in retrieving the lizard caches and in taking
<br />measurements. He and P. Collins also helped identify lizard remains.
<br />LITERATURE CITED
<br />Jurttx, S. A. 1987. Environmental factors correlated with the distribution of island ironwood Lyon-
<br />othamnus Jlonbundus subsp, asp[enifolius on Santa Cruz Island, California. Unpubl. M.A.
<br />thesis, Univ. California, Santa Barbara, 132 pp.
<br />Rnvert, P. H., nr[n D. I. Axet.aon. ]978. Origin and relationships of the California flora. Univ.
<br />' California Publ. Bot., 72:1-134.
<br />Wot.eE, J. 7964. Miocene floras from Fingerrock Wash, southwestern Nevada. Professional Paper,
<br />U.S. Geol. Surv., 454-N:1-36.
<br />PAtn. D. Hnt:tvtlc, Lewis and Clark's Rangers, 3724 Boca Chico Blud., Suite C-200, Brownsville, TX
<br />78521.
<br />1VSULARIS)
<br />:EE
<br />~s on Santa Cruz Island,
<br />salons). One of the jays
<br />d been sitting. The jay
<br />-nts, it tried to stuff the
<br />nd the object fell to the
<br />and flew into another
<br />in the bark of the trunk
<br />bird Lyonothamnus tree
<br />the bark, poked a dead
<br />and retrieved the cache.
<br />with-its head, tail, and
<br />~e seen from the outside.
<br />to a new Lyonothamnus,
<br />-staphylos), and Catalina
<br />t bark of Lyonothamnus,
<br />izard (Uta stansbunana)
<br />jays' behavior. Later, I
<br />zards out of sight. Five
<br />• trunk ar a large limb.
<br />n 3.8 to 7.3 m above the
<br />lizards. Sometimes the
<br />:mbered and ate part of
<br />e lizard. One jay cached
<br />OBSERVATIONS OF SPAWNING RAZORBACK SUCKER
<br />(XYRAUCHEN TEXANUS) UTILIZING RIVERINE
<br />HABITAT IN THE LOWER COLORADO RIVER,
<br />ARIZONA-NEVADA
<br />Once common throughout the Colotado River drainage, the razorback sucker (Xyrauchen texanus)
<br />is now rare (Holden and Stalnaker, 1975; Minckley, 1983). Attempts are being made by the U.S. Fish
<br />and Wildlife Service and the Arizona Game and Fish Department to recover the spades in the lower
<br />Colorado River Basin by reintroduction of hatchery fish (1981 Cooperative Agreement). Although
<br />generally considered a riverine species, spawning observations and studies in the lower basin have
<br />primarily focused on relict reservoir populations (Ulmer, 1980; Minddey, 1983; Marsh and Langhorst,
<br />in press). While rivenne spawning has been suspected (Minckley and Carothers, 1979; Minckley,
<br />1983), observations have not been substantiated by collection of eggs or larvae.
<br />Species scarcity, logistical problems associated with underwater investigations, and poor water vis-
<br />ibility have contributed to the lack of information concerning this species' use of river habitats. However,
<br />downstream from Hoover Dam, Arizona-Nevada (Fig. 1), visibility often exceeds 15 m, and razorback
<br />suckers are common.
<br />In 1983 (Minckley, ] 983) and 1984, razorback suckers were observed exhibiting spawning behavior
<br />in the Colorado River 4.8 km below Hoover Dam. Since then, evidence of spawning razorback sucker
<br />has also been discovered (pers. obser.) in the river downstream oC Davis Dam, which impounds Lake
<br />Mohave.
<br />On 28 January 1984, divers snorkeled several areas along a 6-km section of river downstream of
<br />Hoover Dam which were thought to be likely spawning areas. These included coves, hot spring areas,
<br />and ponions of shoreline. Razorback suckers were observed in several areas; however, actual spawning
<br />or any indication that the substrate had been disturbed by spawning activities was limited to one
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