Post #6 Diet of Western Screech-Owls

According to Birds of the World, Western Screech-Owls eat a large variety of prey. “Diet varies tremendously from place to place and season to season.” Items documented in the diet include:

            Invertebrates – carpenter ants, moths, crayfish, caterpillars, Jerusalem crickets, whip scorpions, and earthworms.

            Small birds – House Sparrow, and Violet-green Swallow nestlings.

            Large birds – Northern Flicker and Swainson’s Thrush.

            Small mammals – shrews, desert pocket mouse, deer mouse, southern grasshopper mouse, kangaroo rat, and big brown bat.

            Larger mammals – white-throated wood rat and cottontail.

            Fish – trout, mountain whitefish, and tidepool sculpins.

            Amphibians – Pacific tree frogs.

            The only food item we’ve been able to identify so far are earthworms. The male is also delivering smaller items that we can’t make out. We’ve not yet seen evidence of birds or mammals. This video shows the delivery of one delicious earthworm. 

            It turns out that earthworms are actually quite rich in protein and various amino acids. The protein content of earthworm meal was 54.6–59.4% on dry weight. Their protein content and amino acid composition are better than those of fish meal, cow milk, and soybean meal. The crude fat content of earthworm meal was 7.34%. If you want to know more, check out “Nutritive Evaluation of Earthworms as Human Food” (Sun and Jiang 2017). Me? I'm moving on to another food topic.