ter are either permanent resident

adults or possibly migrant birds from

farther north in Canada. Our prelim-

inary results indicated that consider-

ably more hatch year birds overwinter

than Pitelka had suspected, but the

evidence is still strong that a differ-

ential migration based on age does

exist. With a differential migration,

we might expect four potential breed-

ing classes of jays in spring: 1) perma-

nent resident adults, 2) permanent

resident hatch year birds, 3) migrant

hatch year birds, and 4) possibly some

adult migrants. By the time the mi-

grant birds return to these northern

latitudes (about the second week in

May), the overwintering adults have

already begun nesting, and we will be

interested primarily in determining in

1981 whether these new arrivals can

compete successfully as later breed-

ers, and whether the relatively few

young birds which overwinter are able

to breed in simultaneous competition

with adults. By trapping intensively

during the winter of 1980-81, we hope

to be able to color mark the majority

of resident birds so that we can iden-

tify most of the breeding jays in the

spring of 1981, thereby coming closer

to answering the question of breeding

success based on age class.

Because Blue Jays appear to make

use of a fairly large winter feeding

range, it is possible that some of the

color banded Cedar Creek birds will

wander away from the study area.

One jay already has been recovered

from Stacy, about 16 km east, and

birds have been spotted up to 5 km

away at feeding stations. Observers

of these birds are asked to report the

following information: location, date

and time of sighting; color band/

aluminum band combination (most

birds have two bands per leg, includ-

ing the aluminum; colors used include

red, yellow, light blue, light green,

white, black, orange, and lavendar);

general habitat type; activity of the

bird. If the jay has been captured by

another bird bander, please measure

the wing chord, culmen, taursus, tail,

and weight, and release the bird. Dead

birds should be frozen immediately

with the bands intact.

Please report sightings to Hilton at

the address or phone numbers below,

and inform the Bird Banding Labora-

tory, Laurel MD 20811. We would also

appreciate information about active

nests in the Minneapolis-St. Paul met-

ropolitan area in 1981-83 so that nest-

lings can be banded, and would like

other information about Blue Jay

breeding habits and success during

past years. Nests found in future sea-

sons can be reported to Hilton or to

the Minnesota Rare Bird Alert num-

ber.

This study was funded in part by the

Dayton Natural History Fund of the

University of Minnesota, and by the

Cedar Creek Natural History Fund.

We would like to acknowledge the as-

sistance of James L. Howitz, David J.

Vesall and Millie Hayes, the coopera-

tion of the residents of the subdivision

adjoining Cedar Creek, and the advice

of Dr. Harrison B. Tordoff.

LITERATURE CITED

Pitelka, F. A. 1946. Age in relation to

migration in the Blue Jay. Auk

63:82-84.

Roberts, T. S. 1932. The Birds of Min-

nesota, Vol. 2. Univ. of Minnesota

Press, Minneapolis.

*Bell Museum of Natural History,

Univ. of Minnesota, Minneapolis, MN

55455. (612) 464-2566 or (612) 373-

3192.

**4225 233rd Lane NE, Bethel, MN

55005.

Winter 1980

149