hence play a leading part in those highly important activities that only the 
Federal Government can conduct. Among these are the promulgation of regula= 
tions protecting birds migrating between the United States and Canada and 
Mexico, an annual task .since 1918, and the establishment of a system of mi- 
gratory bird refuges giving adequate protection: to wild fowl on the breeding 
and wintering grounds and throughout the major flyways of the United States. 
FOOD AND COVER TECHN IQUaS 
Coexistent with study of the identity, distribution, and migration of 
‘animals from the inception of the Fish ard wildlife Service, was research into 
their food habits. From.this technique have developed, partly because of 
actual relationship, and partly through accidents of administrative history, 
a number of other techniques for the improvement of environment and for the 
encouragement of deSirable and the control of undesirable species, which are 
today. the very warp and woof:or the wildlife manager's art. 
Originally developed to throw light on economic values in relation to 
agriculture, horticulture, and forestry, this work soon responded to the 
needs of wildlife management, although that term was then unknovm. A compre- 
hensive report on the food habits of the bobwhite was published in the Year- 
book of the Department of Agriculture for 1903. This was revised in bulletin 
form and accompanied by accounts of 6 other species of quail in 1905, ard in 
the same year a similar bulletin treating 12 species of grouse and the wild — 
turkey was issued. Systomatie research on the food habits of wild fowl was 
begun in the laboratory in 1905 ard in the field in 1908. . The first -publi- 
cation on wild-duck food plants eppcared in 1911, and it has been succeeded 
by &@ number of papers on that subject,, 
the. contents of the alimentary canals of collectsd specimens, of feces and 
regurgitated pellets, of food remains at dens, nests, and roosts, as well as” 
ali practicabie field investigations of feeding habits and of the utilization 
of food supplies. ‘Such studics yield data, not only on specific food habits 
but also on the local, seasonal, and general value of food items, that are of 
fundamental utility in wildlife -management. 
Knowledge of the relative importance of the various constituents of 
wildlife subsistence naturally led to efforts to increase the more valuable 
kinds. These efforts developed in one direction into recommendations as to 
choiee, of kinds, as so care of propegating material,.and as to uhere, when, 
and how to set out valuable wild-duck food plants. Later, plants affording 
rerupe shelter and nesting cover were. included, and the technique, in effect, 
became one of general improvement of the énvironmont of wild fowl. These 
recommendations were acted upon extensively through = long scrios:of years 
and resulted in great improvemert of some propertics (up to a tenfold increase 
by the financial scale), and are now serving as the basis of development and 
improvement of the vast rew system of national wildlife refuges (more than 200, 
totaling more than 4,200,000 acres, primarily for waterfowl, within the limits 
of the 48 States.) Recommendations as to the value of marsh and aquatic plants 
and as to methods of propagating. them have been of value also to a branch of 
the fur industry, namely muskrat.farming. The demand for these plants, largely 
3 
