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availability of such physical habitat as an impediment to the achievement of recovery <br />goals. <br />The argument that maintenance of a high availability of habitat for adult Colorado <br />squawfish is important to recovery is not entirely speculative. There are data that <br />suggest the availability of habitat for adult fish could have an important effect on the <br />size of the adult population. That argument is based on the observation that Colorado <br />squawfish can make extensive spawning movements and, more important, return to their <br />former home range subsequent to spawning (e.g., Miller et al. 1983). The return of <br />Colorado squawfish to feeding/wintering areas occupied during the non-spawning season <br />is remarkable because during its accomplishment the fish pass through river reaches that <br />contain suitable feeding/wintering habitat--habitats so used, in fact, by other Colorado <br />squawfish. Because such migrations require the fish to expend considerable energy, one <br />must ask why the adult squawfish simply do not remain in the adult feeding/wintering <br />habitats nearer their spawning area. This presumably would conserve energy and thus <br />would be advantageous to the survival of the individual fish. But the adults return to <br />their former feeding/wintering areas after spawning. The most dramatic example of this <br />homing behavior is the return of adult Colorado squawfish to the upper White River, <br />after they have traveled more than 150 miles to spawning sites on the lower Yampa <br />River (Miller et al. 1983). Numerous other, less dramatic examples have been recorded <br />throughout the upper basin. <br />A possible explanation for this major expenditure of energy to return to former <br />feeding/wintering areas is that it represents a needed disbursal of the adult population <br />throughout the range of the species. Without such disbursal, negative interactions-- <br />8