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 July, x9o6 I 'FILE BARN OWL AND ITS ECONOMIC VALUE 87 exmnination of these pellets, found about the nest or under the roost, a scientist can get a perfect index to the character of the food that has been eaten. In addi- tion to this, one generally finds in the nest the remains of creatures upon which the young birds have been feeding. The owls as a family are the most beneficial of predaceous birds from the eco- nomic standpoiut of the farmer. With few exceptions they are nocturnal. Their eyes and ears are remarkably developed and are keenest in the early hours of the night and morning. Many harnfful rodents are most active in their search for food during the night, and the owls are the natural check for this nmltitude. The hawk hunts by day and the owl by night and the work of the one supplements that of the other. A pair of barn owls occu- pied one of the towers of the Smithsonian Institution at Washington. When the young were half grown, the floor was strewn with pellets. An examination of two huu- dred of these showed a total ,, of four hundred and rifty skulls. Four huudred and " "" twelve of these were nrice,, twenty rats, twenty shrews, one mole and a vesper spar- rOW. A family of young owls will number from three to seven birds. It is incredible what an amount of vermin a finnfly of owls will consume. An old owl will capture as much or more food than a dozen cats in a uight. The owlets are always hungry; they will eat their own weight in food every night and more if the), could get it. A case is on record where a , , half grown owl was given all the mice it could eat. It swallowed eight in rapid suc- o,m^,, o uv ,ow, ^,, ow cession. The ninth followed cp.r, Ltfhl photo by I. T. Eohlman and Hm. l.. einley all but the tail which for some time hung out of the bird's mouth. The rapid di- gestion of the Raptores is shown by the fact that in three hours the little glutton was ready for a second meal and swallowed four additional mice. If this is the perfornmnce of a single bird, the effect that a whole nestful of owls would have on the vermin of a community is self-evident. I wondered at the changes in the owl faces as they grew older. When I first saw them in white down, I thought the face was that of a sheep, and then a monkey, and then I didn't know just what it resembled. The third time we vis- ited the nest;, each youngster had a face that surely looked like some old grand-