whereas in other pellets the
only residue was finely divided chaff. Certain foods that lack hard
parts may leave no recognizable residues in pellets. A captive crow that
I raised did not form pellets when fed soft food. Nevertheless, data
from analysis of pellets when supplemented by field observations, should
serve as a sound basis for valid conclusions concerning the relative
proportions of various foods eaten. The following field observations of
habitat factors aid in interpreting the information obtained from pellet
analysis.

Field Observations and Correlations

RESIDENT CROWS IN EASTERN HARVEY COUNTY.--Although no field observations
were made on feeding behavior in April, the large percentage of oat
hulls found in the pellets suggests that newly sown fields of oats must
have been one of the major feeding grounds in that month. Oats were
planted between February 15 and March 20.

The pellets collected in June were all from the roost of one family
group of crows. This group spent much time in a cherry orchard and in
the shelterbelt near it. Residues of cherry and wheat constituted the
only plant foods found in the pellets. In both frequency and percentage,
scarabaeid beetles constituted the other important food source. The
wheat harvest started on June 17.

The cherry harvest was over by June 29. Grain harvest was over and the
fields were being plowed by July 2. Alfalfa was being cut for hay in
early July and crows were then feeding on plowed fields and the newly
mown alfalfa fields. Much time in the middle of the day was spent along
the creeks where crayfish could be obtained. During most of the summer,
pellets were difficult to find because the roosts were small, shifting,
and scattered and because few pellets were produced. For weeks at a time
there were no usable pellets under roosts occupied by hundreds of birds,
although droppings and feathers were present. At other times large
collections of pellets could be gathered from small roosts. Plowing was
a major farm operation at the season when pellets were most scarce.
Larvae of insects (especially beetles), and earthworms might have
provided a major source of food which lacked sufficient indigestible
material to form pellets. A few feces were collected and analyzed in an
attempt to find the residue of such soft-bodied foods. Indigestible
materials were found in the feces, but these were of the same types as
those found in the pellets. Only a few fragments w