July, 1912 PRESENT AND FUTURE STATUS OF CAUIFORNIA VALLEY QUAIL 
135 
locality. They are as follows ; Food supply, cover, predatory animals and 
birds, disease, weather conditions, and the hunter. 
There is an old biological law which states that birds and animals under 
natural conditions will increase np to the limit of their food supply. On any 
given area there is food and protection for a certain population of plant and 
animal life. Just as soon, therefore, as the food or protection or both are di- 
minished the given area will support less numbers of individuals and vice versa. 
This law is one of the most fundamental of all natural laws and most of the 
fluctuations of numbers of a given species can be traced either directly or 
indirectly to the working out of this law. Such factors as disease, predatory 
animals and birds, and climatic conditions are usually minor external factors. 
If it can be shown, then, that the food supply or cover of the California valley 
quail has greatly decreased in the last twenty years, we should naturally expect 
a decrease in the numbers of quail. If. on the other hand, it can be shown that 
the food supply and cover, or both, has not decreased, or has increased, we 
should naturally expect to find the ([uail holding their own or increasing in 
numbers : that is, barring other factors such as disease, an increase of predatory 
mammals and birds, or hunting. Outside disturbances in the balance, such as 
the hunter, may or may not have a decided influence on numbers, depending 
upon the extent of the destruction. A certain small amount of destruction 
probably would have little or no effect on the numbers, as this depletion would 
simply leave more room for others and a larger percent of the birds hatched 
would live. 
Ihider natural conditions, therefore, the food supply of a bird probably has 
more to do with the numbers than any other thing. The cultivation of land, 
which is becoming more and more general each year, causes the destruction 
of the natural food of many of our birds. In a few instances certain birds are 
profiting by a new supply of food furnished by the crops raised : but in most in- 
stances the intensive cultivation of land brings a diminution in the numbers of 
birds very largely due to a destruction of their natural food. It is pleasing to 
note that the quail are among the birds which have, to some extent at least, 
adapted themselves to the new conditions. It has been stated that no birds 
flourish under so many varied conditions as do the California valley (|uail ; for 
they can be found from sea level to a mile alx)ve the sea, and from the humid 
coast belt to the desert. They have been found breeding in tides, in vineyards, 
in the iveeds along fences, in orchards, and even in suburban gardens. Vine- 
yards furnish them not only acceptable food but good cover. The (|uail being 
largely a seed eater, will turn to grain, grapes, and other cultivated products 
when its natural food is not available. In spite of this fact, however, the cul- 
tivation of great tracts of wild land accompanied with the destruction of such 
plants as the burr clover, alfilaria, lupine, tarweed, pigweed, and mustard, has 
diminished the food supply of the quail to such an extent that doubtless it has 
had a considerable effect on the numbers. 
The habits of the quail show them to be closely dependent on cover. There 
are many places in the state where it could be definitely shown that the destruc- 
tion -of cover has been the primary factor in the diminishing of the numbers 
of quail. Mot onA is that cover, de.stroyed in the clearing of land, of impor- 
tance, but also the large areas destroyed by fire each year. As the land becomes 
cultivated, but a small amount of cover is furnished in place of that destroyed. 
The weeds and shrubs growing along the fences, and the vineyards, probably 
furnish the best of the new cover. 
