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000119 the weaker animals; 13. migrational movements from one range to another are influenced by time and/or weather; 14. spring storms can reduce the condition of animals and/or reduce the number of individuals in a population; 15. food habits of some species change with the amount of precipi- tation which can be beneficial or detrimental; and 16. use of south facing slopes for food and north facing slopes for protection." [20, p. 8J. Studies of the response of small mammals to winter snow accumulation in the San Juan Mountains [14J do not reveal clearly predictable responses. Lower population numbers seem to occur after winters with late snowpack and late melt. The proximate cause seems to be spring- time shortage of proper food and a shortened breeding season. Other factors, such as changes in land use, appear to have a more direct effect on small mammal populations. The Skywater Programmatic FES states: "On the bas is of the above fi nd i ngs, it is expected that the Skywater programs of field experimentation will have no discernible impact on small-mammal populations. The potential impact of widespread or prolonged application of precipitation management will probably involve occasional episodes or circumstances resulting in temporary declines in small-mammal populations. Because of the large population fluctuations that normally occur, declines caused by these infrequent episodes will be difficult to identify or attribute to speci- fic causes. There appears to be little likelihood that such application will significantly affect the range of diversity of small-mammal species." [4, p. 3-131J The effect of additional precipitation on furbearers, reptiles, insects, and birds has not been considered a controlling factor to the well-being of the various species. Migratory birds would not be affected by winter snowpack increase unless highly augmented snowpacks persisted so as to interfere with breeding seasons or food supply - an unlikely occurrence. Residents are well adapted to conditions of an area, and vary their location/ elevation in alpine settings according to weather conditions. Habitat destruction or alteration is the most serious factor in the well-being of bird populations. Cloud seeding will not contribute to this occurrence. Increased snowmelt will benefit marshes and meadows and the animals that inhabit them. One of the design considerations for the proposed demonstration phase is to determine the type of monitoring required to determine the response of large and small mammals and their well-being to increases in snowfall and snowpack. Knowledge of the potential impact of precipitation management on the principal components of the aquatic ecosystems is limited. An impor- tant question is whether increased snow depth and duration will worsen or extend winterkill occurrences. Some possible effects of wide- 22