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Field
Guide IDs: BREEDING:
Scrub (esp oak,
pinon and juniper), brush, chaparral, pine-oak
woodland. 1 brood, rarely 2. DISPLAYS:
Courting male hops
around female with his head erect, tail spread and
dragging. NEST:
Occ in small conif;
supported by platform of twigs, occ moss, cup of
grass lined with fine rootlets, hair. EGGS:
Pale green marked
with reddish browns or greens. 1.1" (28
mm). DIET:
Mostly insects;
also other invertebrates and small vertebrates,
including bird eggs, nestlings, fledglings. In
nonbreeding season, largely acorns, pinon nuts,
fruit, seeds. CONSERVATION:
Winter resident.
Florida subspecies on Blue List 1973-86. Through at
least 1930s organized "shoots" held by farmers and
fruit growers in CA to reduce jay numbers because
of ostensible damage to crops; nearly 1,500 birds
occ killed in one day. NOTES:
Long-term pair
bond, pair or flock remain year-round on permanent
territory; cooperative breeder in FL. In FL clutch
size usu 3 - 4; predation primary cause of nest
failure, reduced in pairs with helpers. Male feeds
female before and during incubation. Female does
most of brooding. Cache food and steal from Acorn
Woodpecker caches; likely serve as major disperser
for oaks and pinon pines by burying acorns and
seeds and failing to recover them. Perch on deer
and remove ticks. Common to abundant
resident throughout campus, especially in
oak-dominated habitats, where it feeds on acorns.
Also eats a variety of fruits (including those of
the eucalyptus), preys upon insects and small
vertebrates, and scavenges discarded food items at
Tresidder Union. Scrub-jays on campus have been
seen killing and eating fully-grown juvenile
European Starlings. ESSAYS: Cooperative
Breeding;
Blue
List;
Hoarding
Food;
Finding
Hidden Caches;
Population
Dynamics;
Natural
Selection. REFERENCES:
Atwood, 1980;
Ehrlich and McLaughlin, 1988; Goodwin, 1976;
Woolfenden and Fitzpatrick, 1984. |
