Geology topics

Laurel F. VanCamp

Publications and source records attributed to Laurel F. VanCamp.

2 recordsLinked to original sources

USGS1979

Annual weight cycle in wild screech owls

The annual weight cycle of wild birds of prey has received little attention in the past, primarily because of the difficulty in capturing and recapturing them. Screech Owls ( Otus asio ) are resident in our northern Ohio study area and readily occupy nest boxes established for Wood Ducks ( Aix sponsa ) (see VanCamp and Henny 1975). In addition to nesting in the boxes, the owls use them as roosting and feeding stations during the winter and are easily captured in the boxes during the day. Therefore, the owls presented an unusual opportunity to obtain information on their annual weight cycle. Between January 1975 and December 1978, Screech Owls were captured, weighed, and banded. Several were subsequently recaptured and weighed again to form the basis of this report. It is difficult to sex live Screech Owls in the field because they are not sexually dimorphic; however, Sherman (1911) noted that females did all of the incubating. We sexed adult owls with young at nest sites by the presence (female) or absence (male) of a brood patch. Owls captured away from nests during the nesting season without brood patches, or at other times of the year, were classified as sex unknown, unless they were previously captured at a nest with young. Screech Owls in northern Ohio have young in the nests from mid-April through early June.

The Auk↗

USGS1975

The screech owl: Its life history and population ecology in northern Ohio

The screech owl ( Otus asio ) is native to North America and breeds throughout the United States and in portions of Canada and Mexico. It is a small owl, 20 cm (8 in) in length from the tip of the bill to the tip of the tail, with a wing span of 56 cm (22 in); it has yellow eyes and prominent ear tufts (see Frontispiece). Although the species is common throughout much of North America, it has not been studied intensively, particularly over a long period. The published literature is concerned mostly with food habits, color phase, taxonomy, and miscellaneous observations. Breeding biology and population dynamics have received little attention. This report presents the basic life history and population information about screech owls in northern Ohio over a 30-yr period. The owls studied were nesting in boxes (Fig. 1) established for wood ducks ( Aix sponsa ) along rivers, creeks, and marshes in a four-county area (Ottawa, Sandusky, Wood, and Lucas Counties) near Lake Erie (Fig. 2). No special trapping techniques were required as the screech owls readily used these nesting boxes and could be easily captured while in them. More than 3,000 owls were captured and banded; 500 were recaptured after the initial banding, some 10 or 15 times. This process provided a large quanity of basic information for this report.

Ohio↗