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000588 Mitchell (1995) identified 308 ponds -- 253 along the Colorado River with a total surface area of 721 acres and 61 along the Gunnison River with a total surface area of 197 acres. Mitchell reported that most of these ponds were less than 5 acres in surface area. The tota 1 number . of 308 ponds i nc 1 udes the Upper Colorado Ri ver from the Colorado-Utah state 1 i ne upstream to Palisade, Colorado. That number does not include numerous ponds that occur in the floodplain from Palisade upstream to Rifle, Colorado. There are numerous ponds along the Upper Colorado and Gunnison rivers that will serve as alternate feeding areas for fish-eating birds. Since nonnative fish would be removed from only a small proportion of the ponds in the project area in any single year (not more than 25 ponds or 8% of the 308 ponds identified by Mitchell (Martinez and Nesler 1996), many other ponds would still be available as alternate feeding areas. In add it ion, adequate shallow backwaters of the ri vers and embayments connected to the rivers contain numerous small fishes that are available to bi rds that depend to a 1 arge extent on fi sh as food. These habi tats, 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 bottoml and habi tats. Fi sh 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 Wil dl i fe Database 1997). Most great blue herons are mi gratory 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 fi sh that are ki 11 ed wi th rotenone wi 11 be eaten by some bi rds . 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 19