Sept, 1914 
SURVEY OF BREEDING GROUNDS OF DUCKS 
235 
Grass, grain or alfalfa fields at a distance Mallard, Pintail, Cinnamon Teal 
from water 
Sage or other brush in vicinity of water Mallard 
The same sort of preference for particular associations was noted in con- 
nection with the shore-birds. Killdeer almost invariably chose the alkali flats 
or bare dry ground ; Avocets were found to choose muddy or grassy islands or 
margins of ponds, whereas Stilts almost invariably chose the muddy islands 
or margins of ponds. 
In explanation of this associational distribution I need but quote from 
Grinnell (Univ. Calif. Publ. Zook, 12, 1914, p. 96) : . . associational restric- 
tion appears to be governed by the following three factors, of relative import- 
ance in the order named. 
“1. Kind of food supply afforded, with regard to the inherent structural powers of 
each of the animals concerned to make it available. 
“2. Presence of safe breeding-places, adapted to the varying needs of the animals, 
in other words, depending upon the respective inherent powers of construction, defense 
and concealment in each species concerned. 
“3. Presence of places of temporary refuge for individuals, during day time or 
night time, or while foraging, when hard pressed by predatory enemies, again correlated 
with the respective inherent powers of defense and concealment of each species in- 
volved.” 
OUR NATIVE BREEDING STOCK OF DUCKS AS COMPARED WITH THE WINTER 
SUPPLY OF MIGRATORY DUCKS 
The supply of ducks in California is derived from two seasonal categories 
of birds, one consisting of those which nest wholly to the north of us and come 
here only in the winter season, and the other, of those which nest here and 
either remain throughout the year within our borders or go farther south for 
the winter. Hunters depend at the beginning of the season chiefly upon the 
supply of native ducks and always maintain that these are the most desirable 
for the table. Home bred ducks are nearly all grain feeders and so lack the 
fishy taste so often found among the northern bred ducks. Numbered among 
the more desirable resident ducks are the Mallard, Pintail, Gadwall, Redhead 
and Cinnamon Teal. It is only the native contingent which we are in a position 
to control during the breeding season. The most important time for applying 
methods of conserving our duck supply therefore falls during spring and sum- 
mer. It is a well-known fact that so long as game birds are unmolested on 
their breeding grounds they are best able to withstand a considerable toll each 
year. It thus becomes extremely desirable that California direct especial 
attention to the breeding grounds of the ducks which are strictly her own, and 
over which she exercises control at all seasons. If the native stock eoidd be 
well conserved there would always be a supply which could be depended upon 
no matter what became of the winter birds. Our summer birds, too, are those 
likely to be seen and studied by the summer vacationist and which therefore 
give most pleasure to those people who do not hunt. 
It is pre-eminently the duty of the State to conserve our native ducks, 
first, because they are highly desirable as food, second, because they are alto- 
gether our own and under our control, and third, because our native ducks are 
the ones available during the most favorable season for esthetic enjoyment by 
the people of the state. 
SUCCESS AND FAILURE AMONG NESTING DUCKS 
There are many factors which contribute to the success which attends 
