WE WERE NOT PLEASED to read in the Federal Register of July 25 that the Fish and Wildlife Service has deregulated the Mexican duck. The duck's deregulation means that henceforth neither it nor the "mallard X Mexican duck intergrade" will be protected under the Endangered Species Act of 1973, but instead will be provided "a more appropriate level of protection" under the Migratory Bird Treaty of 1918. This sudden decision, which represents a reversal of a prior position, was based on the discovery that the great majority of Mexican ducks (Anas diazi) have been interbreeding with the common mallard (Anas platyrhynchos) and have thus protected themselves by producing the heartier duck (Anas diazi platyrhynchos). In short, most of the Anas diazi will be deregulated because they have played around, and the rest will be deregulated even though they have not.

We don not wish to involve ourselves in the web of evidence in this matter - although it certainly seems that most of the conclusions of the Fish and Wildlife Service are based on canards. But the principle of fairness here seems extraordinarily arbitrary. The morality of the ducks aside, have not the Anas diazi shown the initiative and pluck ideally expected of any federally supported animal? And does not the public, which foots the bill, have some say in these things?

The service found that "all presently known methods of karyotyping, allozymic variation analysis, and protein analysis would not provide sufficiently reliable insight as to the taxonomic relationship between methods have great difficulty in separating congeneric, let alone conspecific, taxa." We agree.

What we do not agree with, however, is the idea of deregulating ducks on grounds of social preference. There is no surer way to bring a civilization down.