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22 WESTERN NORTH AMERICAN NATURALIST 210 205 200 195 a~ w a~ 0 190 Y ~, 185 .~ 180 175 170 165 [Volume 60 4/15 5/15 8115 7/15 8/15 9115 10/15 11115 12/15 1/15 2/15 3115 4/15 1993 1994 Fig. 3. I,oc;ations of 12 radio-tagged Colorado pikeminnow (Ptychocheilus lucius) translocated above Taylor Draw Dam and subsequently contacted in Kenney Reservoir and the White River, Colorado, above Taylor Draw Dam (km 168). the dam but had located themselves 5.6-26.6 km below the dam by October 1993. Fish movement in September and October 1993 was 3- to 6-fold greater than the movement exhibited by these fish during tl~e same period in 1992. It is unknown why these fish moved downstream of Taylor Draw Dam in 1993 when they congregated below the dam during the same period in 1992. The average dis- charge at the dam during the months of August, September, and October was more than 1.5 times greater in 1993 than in 1992. In addition, a new hydroelectric generator was installed and in operation by summer 1993 and caused some redirection and fluctuations of flows in the river channel directly below the dam. Although these fish were not tracked again until April 1994, they showed movement pat- terns similar to those in April 1993. The great- est amount of fish movement in the White River was displayed by the 8 fish placed above Taylor Draw Dam in April 1993 and the 2 fish placed in Kenney Reservoir in September 1993. The 8 fish moved 1.1-40.6 km between April and July 1993; the other 2 fish, which over- wintered in the river above the dam, moved 10.5-19.3 km between September 1993 and Apri11994. DISCUSSION Colorado pikeminnow in the White River moved long distances annually. All 12 Colo- rado pikeminnow monitored from 1992 to 1994 migrated from the White River and were located at or near the spawning sites, or appar- ently en route to the sites in the Green and Yampa rivers. They then returned to areas near their original capture sites below Taylor Draw Dam. All demonstrated movements to spawning areas previously described by Tyus (1990): 7 migrated toward the Yampa Canyon spawning site and 5 toward the Gray/Desola- tion Canyon site. They also displayed fidelity to a single site and migrated the same direction in successive years. Our observations indicate that many wild adult Colorado pikeminnow in the White River undergo annual migrations to spawning sites. It is unknown whether these fish actually spawn each year. Although we contacted all migrating fish within a few kilometers of the known spawn- ing sites, telemetry was limited, and we were unable to locate each fish at its respective site. Either they reached the sites between our con- tacts or they might have migrated to other concentration points near the spawning sites. t ii _ (~ ` ~ ` h;,,_~ C~ i ~. df2 i.4~~r ~N y';r 1 ie+..,~ , v~.~~ ~. ` ~ i (t '~~r ~ t.~r ~ - ~ i I _ ~ ~ ..ra•e { wr xtv L-~~r r, , 1;J }. } ~2}rl lo' ~'~ K. 1.j~5 ~2.F~"j ` ~ ~,2 'T t.I • 14 i~ x° ~ ~ ~` 7 ~P a.. ,-- a`r \~ t1 ~~^: ~ ~~ i. Sn"E ;ly ~~ ~ ~ t~ ~ f \ -'Y..t& ~a x -. t ~ ~~ ~ ~ ' t ~. ~ 7 ~~..:Y t~ ~,-~tl~-'' ~~;: ~ k ~::~,_ i~~7~~~`~ .~~ 't ~ i-41~~ v, _ tt ~ y. x w_ r ~, i ~ ~ ~"s _~;?~i ~ .: n-ti.-,. .>''1~. i~~....i i~ _4i ~~`~~ l ~ ~ti_'t~~a.~re~,~x~~~: ~q~li`ve~*L r w~ „~ •ri ~r~..:ti~+1...L.. r .. _tc ,: ~•~t._a*a.: -3.^. ~^a i.,.: 1.~56`,i