Field
Guide IDs:
BREEDING:
Open and
partly open habitats, esp grassland,
farmland, often in or near towns. 1, occ 2
broods. DISPLAYS:
Male claps
wings together in courtship flight;
ritually presents food to
female. NEST:
Also in
cliff crevice, occ excavate burrow in
arroyo wall. Usu unlined, occ lined with
wood chips, sticks, etc. EGGS:
White,
often nest-stained. More elliptical than
eggs of other owls. 1.7" (43
mm). DIET:
Mostly
rodents (esp voles), rarely amphibians,
reptiles, insects. Elects
pellets. CONSERVATION:
Winters
within U.S. Blue List 1972-81, Special
Concern 1982-86; widely declining largely
due to habitat loss as grassland and
farmland reduced by suburbanization.
Readily use nest boxes. NOTES:
Clutch
size reflects prey availability and
severity of preceding winter; fledging
success also low following severe winter.
Male feeds female throughout incubation.
Young hatch asynchronously, spanning up to
14 days. Male and female brood. Sway
lowered head from side-to-side when
confronted. Roosts diurnally, occ
communally, leaving roost singly before
sunset and circling upon
departure. Several
pairs are resident on campus. Nests on
artificial ledges and cavities on several
buildings, and (probably) natural tree
cavities and within the dense crowns of
palms. Often seen day-roosting in palms
near the mausoleum or seen (and heard)
flying over the main campus at
night. ESSAYS: How
Owls Hunt in the
Dark;
Pellets;
Blue
List;
Brood
Reduction;
Variation
in Clutch
Sizes. REFERENCES:
Bunn et
al., 1982; Colvin, 1985; Cramp, 1985;
Earhart and Johnson, 1970; Marti and
Wagner, 1985.
Tyto alba Scopoli
NG-248; G-176; Pl 174; PW-120; AE pl 291;
AW-pl 302; AM(II)-156
Location
Type
Mating System
Parental Care
2ndary Diet..
Strategy
I:30-34
DAYS
SEMIALTRICIAL
2
CAVE
(3-11)
MONOG
MF
Except for Stanford Notes, the material in this species treatment is taken, with permission, from The Birder's Handbook (Paul Ehrlich, David Dobkin, & Darryl Wheye, Simon & Schuster, NY. 1988).