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In addition, adequate shallow backwaters of the rivers and embayments connected to the rivers contain numerous small fishes that are available to birds that depend to a large extent on fish as food. These habitats, adjacent to the floodplain, would likely provide suitable alternative habitats for food, cover, and nesting by various birds. Some reclaimed floodplain ponds will be stocked with either young endangered fishes or sportfish. Other ponds will be reconnected to the rivers as part of the Recovery Program effort to restore bottomland habitats. Fish in these habitats will be available as a forage base for both avian and terrestrial wildlife. Reclaimed floodplain ponds that remain fishless will provide larger numbers of aquatic invertebrates that are used as food by other bird species such as shorebirds and waterfowl. Some ponds, formed from gravel mining operations, are too deep and contain only a small area of shallow water that can be used for feeding by wading birds. In the floodplain areas where these ponds are located, there are numerous shallow backwaters and embayments connected to the rivers containing small fish that are available _-__ as food for piscivorous birds. One piscivorous bird, the great blue heron, is very common in the project area. Great blue heron rookeries are found in the cottonwood riparian zone in floodplains along the Colorado River in the Grand Valley, in the vicinity of DeBeque, and upstream as well as downstream near Rifle (Colorado Division of Wildlife Database 1997). Most great blue herons are migratory in Colorado -- birds arrive at the rookeries in late February and disperse from the sites as the young fledge. Since the great blue heron feeds by wading in shallow waters, many of the ponds in the floodplain (particularly those remaining from gravel mining operations} are too deep for this species or other wading birds to feed effectively. These birds would seek shallow ponds that are natural depressions in the floodplain or other shallow environments such as river shorelines, backwaters, and embayments. Therefore, the impact on this common species by removal of nonnative fish species from floodplain ponds should be very minimal. Some fish that are killed with rotenone will be eaten by some birds. However, rotenone is nontoxic to birds at the concentrations used to kill fish (Bradbury 1986). Therefore, no adverse impacts are anticipated to piscivorous birds that feed on dying fish because it is highly unlikely that they would not eat enough of the fish killed by rotenone to cause toxicity in the birds. In conclusion, it is believed that removal of nonnative fish species from floodplain ponds along the Upper Colorado and Gunnison rivers would not cause a significant adverse impact on fish-eating birds because alternate feeding areas are available adjacent to the floodplains where ponds would be reclaimed. Removal of nonnative fish species from some floodplain ponds along the Upper Colorado and Gunnison rivers will not result in complete elimination of small fish that serve as food for birds. Although there would be a minor negative impact to piscivorous bird species, this would be offset with a positive impact of increased aquatic invertebrates for shorebirds and waterfowl. 20