The Florida Scrub-jay. Our long-term study of the demography
and behavior of the Florida scrub-jay (see photo, this page) continued.
Basic to our research is following the approximately 60 families that
occupy about 2 square miles of scrub at Archbold known as the Demography
Tract. In this tract we conduct monthly censuses, find and monitor all
nesting attempts (see map, page 11), and capture and band all
immigrants. When a jay is captured and banded it is measured. When
nestlings are banded and measured we take a blood sample. Part of the
blood sample is used for sexing the individuals; the remainder, which is
archived at Cornell University, is used for genetic studies. With a pan
balance we regularly obtain weights of some individuals without having
to capture them (see Kim
Brand, page 38). Habitat measurements
include counting acorns produced by approximately 2400 marked oaks
annually and counting insect prey at about a dozen points in the scrub
In 1999 the jays fledged 2.02 young per pair, in 2000 they fledged
1.67; both years were near the long-term, 30-year average of 1.79 young
fledged per pair. A drought began in 2000 that continues in 2001.
Five papers (see Appendix A) reporting on various aspects of
scrub-jay ecology and behavior were published in 1999-00. Peter
Midford, a University of Wisconsin graduate student, Jack Hailman,
and Glen Woolfenden published on social learning (see Ethology,
page 16). Young jays were allowed to watch more experienced individuals
search for peanuts buried within a plastic ring set out in their
territory. Afterwards we determined if the observing jays copied the
behavior they witnessed. As expected, young learn from watching adults
in this family-oriented bird species. Using jays living in the
Experimental Tract, which lies south of the Demography Tract, Ron
Mumme (see page 15), Steve Schoech, John Fitzpatrick, and
Woolfenden demonstrated that scrub-jays living along a rural, high-speed
road do not survive as well as those that live with no such road along
their territory. These results have important conservation implications.
Jim Quinn (McMaster Univ.), John Fitzpatrick, Brad White (McMaster
Univ.), and Woolfenden published on the relationships between behavioral
and genetic parents in the scrub-jays. The answer is straightforward,
the behavioral parents are the genetic parents. Unlike its close
congener the Mexican jay, Florida scrub-jay helpers never produce any
young of their own. Dave McDonald (Univ. Wyoming), Wayne Potts
(Univ. Utah), John Fitzpatrick and Woolfenden showed that greater
differences in genetic structure occur between scrub-jays in Florida
living relatively near each other, but on different ridges, than between
scrub-jays in California that exist farther apart, but in continuous
habitat. Joanna Burger, Mike Gochfeld (both at Rutgers Univ.),
and Woolfenden published on metal concentrations in the eggs of
scrub-jays. Levels were lower than those that cause abnormalities in
Reed Bowman (see pages 12-13) and Woolfenden submitted a paper
comparing the breeding of scrub-jays in natural scrub with those in
suburban housing areas embedded in scrub. Although they start earlier in
the spring and have more attempts, suburban scrub-jays are a population
sink; they do not produce enough breeders to replace themselves.
Furthermore, immigrants do not come from natural scrub source
populations. They are investigating this important finding further.
Other Projects. Keith Tarvin and Woolfenden wrote the life
history of the blue jay for The Birds of North America
series. Many of their conclusions come from field work on the species
done at Archbold. In this paper they suggest that the social system of
the blue jay includes small territories that surround the active nest of
a pair, and otherwise the species lives in small groups of breeding
pairs, which may defend these areas from intruders.
Bill Pranty and Woolfenden reported on the first occurrence of
the northern lapwing in Florida. It was present for several days during
December-January 1997-98 in a pasture near the southeastern shore of
nearby Lake Istokpoga. By wintering in Florida this individual was
wintering about as far south as it does when wintering in its normal
range in the Old World.
Wayne Hoffman, P. William Smith, and Woolfenden reported on an
invasion of southern Florida by short-eared owls from the West Indies.
They characterized the external differences between this form of
short-eared owl, using nine specimens that have been added to the
collections at Archbold, and the one that visits Florida in winter from
northern North America. Almost no overlap occurs in the time the two
populations occur in Florida; the northern one being here in winter, the
West Indian form, representatives of which probably come from Cuba, is
here in spring and summer following post-breeding dispersal.
Bill Smith, Sandy Sprunt (National Audubon Soc.), and
Woolfenden published a paper arguing against the evidence that the
loggerhead kingbird has occurred in Florida. They reviewed the
photographic evidence and concluded they were not pictures of a
loggerhead kingbird, but perhaps of the giant kingbird. If their opinion
is followed the loggerhead kingbird is deleted from the list of birds
known to have occurred in North America.
Based on specimens taken from the swimming pool at Archbold, Walter
Meshaka and Woolfenden reported on the breeding season of the
narrowmouthed toad in south-central Florida. The numerous specimens are
now housed in the herpetology collections at Archbold.
Research on sharp-tailed sparrows continues. Using study skins
borrowed from various museums, Jon Greenlaw and Woolfenden are
determining the wintering ranges of the five recently recognized forms,
the salt-marsh sharp-tailed sparrow with two races, and the Nelsonís
sharp-tailed sparrow with three races. The salt-marsh species breeds
along the Atlantic coast from Maine to Virginia; Nelsonís species
breeds from Maine inland across northern North America to the prairie
provinces. Combined, the two species winter along the maritime coasts of
the Atlantic Ocean and Gulf of Mexico west to Texas. Does the maritime
breeding salt-marsh sharp-tail ever cross to the Gulf coast to winter?
How far north along the Atlantic coast does the inland breeding Nelsonís
sharp-tail winter? These are among the questions they hope to answer.
Curt Adkisson (see page 14) continues his research on blue jay
caching behavior. Currently he is focusing on individuals that harvest
from Archbold oaks and cache in adjacent citrus groves.
The Collection. Valuable specimens continue to be added to the
collections housed at Archbold Biological Station. Among others added
were study skins of Florida specimens of scrub-jays, blue jays,
short-eared owls, band-rumped storm-petrels, sharp-tailed sparrows, and
calliope and broad-tailed hummingbirds. Bob Duncan, Mike McMillian,
Wayne Hoffman, and Ron Smith were among the donors.
The Bird Lab lost a long-time friend and collaborator on 28 January
2000 when William B. Robertson, Jr., died at home in Homestead, Florida.
Biennial Contents | Top