In California and adjacent States two species of jays are much in
evidence under several more or less well-marked forms.
The Steller jay[46] much resembles the eastern bird, but it is more shy
and retiring and seldom visits the orchard or vicinity of the ranch
buildings. Stomach examination shows that its food does not radically
differ from that of the eastern blue jay. As is the case with that bird,
a very considerable part of the food consists of mast, together with
a little fruit and some insects. The insects are largely wasps, with
some beetles and grasshoppers. This jay also eats some grain, which is
probably waste or volunteer. No complaints, so far as known, are made
against this bird. Until it shall become less wary it is not likely to
trespass to a serious extent upon the farmer's preserve.
[46] _Cyanocitta stelleri_.
The California jay,[47] although of a different genus, more nearly
resembles its eastern relative in food habits and actions. It freely
visits the stockyards near ranch buildings, and orchards and gardens. As
a fruit stealer it is notorious. One instance is recorded where seven
jays were shot from a prune tree, one after the other, the dead bodies
being left under the tree until all were killed. So eager were the birds
to get the fruit that the report of the gun and the sight of their dead
did not deter them from coming to the tree. In orchards in canyons or on
hillsides adjacent to chaparral or other cover great mischief is done by
this bird. In one such case an orchard was under observation at a time
when the prune crop was ripening, and jays in a continuous stream were
seen to come down a small ravine to the orchard, prey upon the fruit, and
return.
[47] _Aphelocoma californica_.
Fruit stealing, however, is only one of the sins of the California jay.
That it robs hens' nests is universal testimony. A case is reported of a
hen having a nest under a clump of bushes; every day a jay came to a tree
a few rods away, and when it heard the cackle of the hen announcing a new
egg it flew at once to the nest. At the same time the mistress of the
house hastened to the spot to secure the prize, but in most cases the jay
won the race. This is only one of many similar cases recounted. The jays
have learned just what the cackle of the hen means. Another case more
serious is that related by a man engaged in raising white leghorn fowls
on a ranch several miles up a canyon. He stated that when the chicks were
very young the jays attacked and killed them by a few blows of the beak
and then pecked open the skull and ate out the brains. In spite of all
efforts to protect the chicks and kill the jays the losses in this way
were serious.
Examination of the stomachs of 326 California jays shows that 27 per cent
of the contents for the year consists of animal matter and 73 per cent
of vegetable. Although the great bulk of the animal food is made up of
insects, the remains of eggshells and birds' bones appear much too often.
The insect food is fairly well distributed among the more common orders,
but grasshoppers are slightly the most numerous and constitute 4.5 per
cent of the year's food. In July, August, and September, however, the
amount is 14, 18, and 19 per cent, respectively. Four per cent of the
food consists of wasps, bees, etc., but in the three months named they
constitute 15, 7, and 9 per cent, respectively. A worker honeybee found
in each of two stomachs is rather surprising, for it is unusual to find
a bird like the jay eating these active and elusive insects, which enter
into the diet of the flycatchers. The remainder of the insect food is
pretty evenly distributed among beetles, bugs, flies, and caterpillars.
Eggshells were found in 21 stomachs and birds' bones in 5. Six stomachs
contained the bones of mammals and two those of a lizard. No bird has a
worse reputation for nest robbing than has the eastern jay, and yet of
530 stomachs of the eastern species only 6 contained eggshells or the
bones of birds. This comparison serves to show what a marauder and nest
thief the California jay really is.
In its vegetable diet this bird much resembles its eastern relative,
the most remarkable difference being in the matter of fruit eating.
With greater opportunities the California bird has developed a greater
appetite for fruit and indulges it to the fullest extent. Remains of
fruit were found in 220 of the 326 stomachs. The percentage for the year
is only 16, but for the four months of June, July, August, and September
it is 44, 33, 53, and 25, respectively. Cherries, apricots, and prunes
are the favorites among cultivated fruits, and elderberries are relished
to some extent. Grain, which was found in 48 stomachs, amounts to 6 per
cent of the food of the year. Practically all of it was taken in the
four months above mentioned, but it is not probable that much damage
is done by the jay in this respect. The major portion of the grain was
oats. What was not wild was probably simply scattered grain gleaned
after the harvest. Mast is eaten by the California jay from September
to March, inclusive, and constitutes during most of that period one of
the principal elements of its food. In this respect the bird shows a
remarkable similarity to the eastern species. A few weed seeds and other
miscellaneous items make up the balance of the vegetable food.
In summing up from an economic point of view the character of the food of
the California jay, it must be conceded that it is not all that could be
wished. Its taste for birds' eggs and fruit is entirely too pronounced,
and at present the species is superabundant in California. While the
natural food supply of the bird has been lessened by bringing the woods
and brushy canyons under cultivation, the same areas have been planted to
fruit, and naturally the jay takes the fruit as an acceptable substitute.
A considerable reduction of the bird's numbers would appear to be the
only effective remedy.