Food of the Crow, Corvus brachyrhynchos Brehm, in South-central Kansas — John Shaqi
Food of the Crow, Corvus brachyrhynchos Brehm, in South-central KansasPlatt, Dwight R.
Science
Food of the Crow, Corvus brachyrhynchos Brehm, in South-central Kansas
Platt, Dwight R.
Crows
In my samples, plant material amounted to 69 per cent of the
indigestible residues. Similar percentages have been found in other
studies, ranging from 57 per cent (Barrows and Schwarz, 1895:72) to
71.86 per cent (Kalmbach, 1918:43). The percentage of plant material was
highest in the winter. In one collection from a wintering crow roost it
amounted to 99.5 per cent. In December in eastern Harvey County it
averaged only 85.3 per cent. The lowest percentage (20) was found in the
first half of October in eastern Harvey County when grasshoppers
amounted to more than half the diet. At this same time pellets collected
from the wintering roosts contained 72.4 per cent plant material.
Percentages of the chief items in the total food residues,
and (in parentheses) number of sampling periods in which
each item was represented, are shown in the following list:
wheat 23.2 per cent (20), sorghum 15.2 (16), oat 7.8 (8),
sunflower 7.2 (8), corn 5.4 (12), brome 4.2 (5), other grass
2.4 (7), cherry 1.2 (2), beetle 13.3 (21), grasshopper 9.3
(19), ant .7 (3), miscellaneous insect .2 (2), mammal 2.6
(19), bird .8 (1), eggshell .5 (3), snake .1 (2), fish .9
(9), crayfish 2.4 (12), snail .2 (9).
Wheat is the "staff-of-life" of the crows in south-central Kansas and
the percentage recorded in the diet in my study is much higher than the
percentages found by other investigators. Wheat, being the principal
crop in this area, was a readily available food. The fluctuations in the
use of wheat were due to fluctuations in the availability of other foods
that were preferred. In eastern Harvey County wheat consumption was
35.7 per cent of the diet in the latter part of July, and 49.1 per cent
in December.
Consumption of wheat was high (34.4 per cent) during the harvest in
June. However, this does not indicate serious damage since the crow
population at this time was low, and much of the wheat eaten probably
was shattered waste grain. When plowing began, wheat consumption was
much reduced. At the time wheat was sown, September 10 to October 15,
consumption was average to low.
In western Harvey County wheat was less important in the diet of
wintering crows. After reaching a peak (22.7 per cent) in October, just
after sowing, it steadily decreased, varying from 6.9 per cent to none
in December.
The wheat consumption of crows has little significance economically. No
instances of damage were reported to me either at the time of harvest or
at the time of sowing. Although crows undoubtedly do eat wheat from
newly sown fields, this utilization seldom damages the stand. No
evidence of pulling young wheat was found. Most wheat eaten was waste
grain.
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