Even in presettlement days, the arid western climate yielded few wetland oases, mostly in the valleys and basins at the foot of lofty mountain ranges. Although the West still harbors wetlands of astounding productivity--Great Salt Lake, Mono Lake, the Salton Sea--since the 19th century the overall pattern has been one of decline and degradation as attested to by California's loss of over 90 percent of its historic wetlands. These wildlife meccas have receded in the wake of our culture's seemingly unquenchable thirst for water to fuel its growth and development, compounded by our limited compassion for the other forms of life with which we share the planet.

Migration at its best is risky business and now birds' options are further constrained not only by habitat loss but also by contamination or impoverishment of prey populations at remaining wetlands.

In the course of the battle to save Mono Lake, some argued that if water diversions lead to loss of bird populations at the lake then these individuals could go elsewhere. The reality is that many former elsewheres are now nowheres. Water diversions for agriculture and municipal use have destroyed such key wetlands as Owens Lake south of Mono and Tulare Lake in the southern San Joaquin Valley; the latter formerly was the largest wetland system west of the Mississippi River. Others, such as the Klamath Basin marshes on the California-Oregon border or those in the Lahontan Valley of Nevada, have been greatly reduced in size as have their bird populations.

So, given this sobering assessment, what are birds to do? The journeys they undertake and the uncertainties they face are not trivial. Fortunately, many species have adopted a semi-nomadic lifestyle to seek out suitable conditions as wetlands shrink and swell during periods of drought and flood.

Hence, a question more to the point is: what can humans do to enhance birds' chances for safe passage on inherently risky annual journeys? First, we must assemble the facts. In the case of Owens and Tulare lakes, we will never really know what was lost as few ornithologists reported on visits to these areas and almost no quantitative data are available on bird use of these wetlands. This also was true of Mono Lake until concern about the lake's declining level prompted researchers, initially students from U.C. Davis and Stanford, to initiate studies about the lake's birdlife and ecology. Current efforts to save the Salton Sea are similarly hampered by a paucity of biological data.

This is not to say that protection and restoration cannot begin until all the facts are in, as they never are, but that the success of such efforts will be greatly enhanced by in-depth knowledge of the functioning of the systems in question. What species use various wetlands? What are their population sizes, their patterns of seasonal use, their food sources? What are other factors they depend on?

We also have to take a much broader view of each species' requirements, as it may do little to protect Eared Grebe populations at Mono Lake if their habitat is not protected elsewhere and tens of thousands die at the Salton Sea. Knowledge of how species vary in their needs is also important, as protecting or enhancing a certain number of reserves, depending on the type, may benefit some species while leaving others at risk.

Whereas alkali lakes like Mono may be crucial for species such as the Eared Grebe, Wilson's Phalarope, and California Gull, freshwater or brackish wetlands or irrigated agricultural fields are vital for species like the American White Pelican, White-faced Ibis, and Black Tern. Gaining even basic knowledge of a species' distribution, key breeding areas, and habitat use may be enough for conservation purposes depending on whether the species currently is found to have healthy population levels and to be concentrated in protected habitats.

It is also essential to understand the range of habitats each species needs, as these may vary greatly both seasonally and geographically. For example, western populations of the Black Tern breed in shallow emergent marshes or rice fields (in California), stage in fall migration at freshwater or brackish wetlands (e.g., Tule Lake, Malheur Lake, and the Salton Sea), and winter largely in nearshore ocean waters off Central America and northern South America. Given that many species are not limited by political or terrestrial-oceanic boundaries, the mechanisms needed to protect or restore their habitats must not be so limited either.

At Mono Lake, it would be desirable to restore as much wetland as possible, of a diversity of types--freshwater creek deltas and riparian habitat, freshwater ponds, freshwater and alkali marshes, etc. Exactly which wetlands are restored and where will depend on a combination of physical constraints, water availability, and philosophical and political considerations at the local and regional level.

Whatever these may be, let us hope that the plans will result in the most natural healthy ecosystem possible, that management will be flexible enough to make adaptive changes as new data from monitoring are gathered, and that, like the legal precedents at Mono Lake which will influence water law and wetland protection for years to come, the efforts at the lake will serve as a model for restoration both locally and nationally.