Research Report #37 — Blue Jay
For many years scientists and naturalists have been studying and observing the flora and fauna of the Shawangunk Ridge. Foremost among them was Daniel Smiley, for whom Mohonk Preserve’s Daniel Smiley Research Center is named. Dan wrote numerous reports summarizing his observations on various topics. This regularly occurring series will feature some of these reports; some hold tremendous scientific value today and just await an interested researcher to follow up, others showcase a quirky sense of humor or highlight an oddity of nature.
Read the report: Blue Jay. October, 1977. Daniel Smiley.
A Note from Paul C. Huth, Director of Research Emeritus: The Blue Jay, Cyanocitta cristata, is a common, almost ubiquitous American bird of the Family Corvidae. The corvids in North America include the crows and ravens, nutcrackers, magpies, and jays. The Blue Jay occurs year-round in the eastern two-thirds of the country, from the Gulf states to adjacent Canada. As Audubon reported in the 1840s, it “breeds from Texas eastward and northward to the Fur Countries, and as far as the bases of the Rocky Mountains.” He considered it “abundant.” It was likely one of a small group of birds to become well known to the first European settlers as they pioneered their subsistence farms here in the Shawangunks in the late 18th century.
One of the successes of the species, is that it is an omnivore, as observed and described by both Audubon, and contemporary James E. DeKay, in the Zoology of New-York in 1844, “It feeds on chestnuts, acorns, corn, cherries, large insects, caterpillars, and at times of scarcity has been known to feed on carrion. It is also fond of the eggs of the smaller birds, and will not hesitate to devour the callow young.”
In the introduction of his Research Report, Dan says, “As ecologists come to think in terms of ecosystems, the population changes of interacting organisms become important. During my 50 years of bird observation at Mohonk Lake, the Blue Jay (Cyanocitta cristata) has changed status from rare to common, at all times of year.” He went on to say that in the spring of 1917, John Burroughs at West Park had observed an “unusually large migration of Blue Jays. He had seen not one the previous winter, which was unusual.”
Dan made his first record of Blue Jays in 1927, at five diﬀerent locations in the vicinity of Mohonk between March and November. Of interest, he noted that they were “very rare in winter”. In 1928, Dan’s brother Keith noted that the first “arrival” of a “migratory” Blue Jay was on 2 April, and that in the fall they fed on acorns on the ground in the garden. In the summer of 1930, friend, climber, and fellow naturalist Howard H. Cleaves reported to Dan that he had observed the plucked remains of a Blue Jay on the Peregrine Falcon Nest Ledge on Sky Top. In 1934-1935, a few Blue Jays were seen in the woods during the winter, and more were seen in the spring of ‘35. Dan recorded two Blue Jay nests in the spring of 1939. One, below Sky Top, had two eggs on 15 May, and three eggs on the 28th. A second nest with three eggs was found on Millbrook Mountain.
In the decades of the 1940s and 1950s, with some seasonal variability, Dan felt the trend of a “somewhat higher population continued.” Dan felt it “noteworthy” that in 1957 he banded two Blue Jays, “the first in 30 years of banding.” The year 1958 really stood out to Dan, for the “dramatic increase in Blue Jay numbers during both migrations and the following winter… [and]15 were reported on Mohonk’s Christmas census compared to 2 the previous year.” During the winter of 1961-62, they were again noted “as very scarce, generally, but increasing again toward fall. In the fall of 1962, “the number was high again, and 28 were banded for the year. The Christmas count at Mohonk reported 17, the largest number yet recorded.” On 1 October 1963, Dan recorded some 25 fly low over trees on Sky Top, “presumably migrating. At least 3 were carrying what looked like an acorn in their bills.” Dan noted migrating birds usually were in “groups of 10 to 25… flying silently past within ten meters of the tree tops, from northeast to southwest.”
During the next 14 years, until 1976, when this summary was prepared, Dan noted Blue Jay “fluctuations” as he called them, but recognized that the lack of data for some seasons made conclusions “diﬃcult.” But I think Dan captured the essence of his 50 years of observations, in that there are now Blue Jays reliably present every winter, and numbers in summer are consistently higher than he observed in the 1930s. Spring and fall migration was still observable.
Certain of Dan’s detailed observations are especially telling of the naturalist. One I particularly like is from 12 December 1933, recorded on one of his 3X5 species cards, made from the back of a soft light green recycled Mohonk Mountain House menu card from 22 December 1930. He notes, “While watching birds feeding at our shelves I saw a Blue Jay fly down to a low stone wall and pick up something. He carried it up to a branch and spent several minutes pecking at it and eating bits of it. Then he flew down to an oak stub and deposited the remainder in a small crevice in the bark. I saw him apparently pick up something two or three times and deposit it on top of the hidden object. Investigation showed the object to be a crust of whole wheat bread about an inch long which he had covered with a smaller sized piece of wood and a small quantity of snow.”
Dan’s Blue Jay banding records need to be mentioned. Dan obtained his bird banding permit No. 4039, from the Bird Banding Laboratory in 1929, and maintained an active permit for the next 60 years. Dan notes in this report, that “From 1929 to 1934 a considerable amount of banding was carried out at Mohonk, at all times of year... No Blue Jays were caught.” Over the next two decades, while banding occurred, it was at times of year and locations where Blue Jays “might have been caught.” However, 2 were finally banded in the fall and winter seasons of 1957, and 11 in the spring of 1958. As Dan notes, between 1961 and 1976, with banding mostly at the Elms Cottage (DSRC), and near the Mountain House, “some 350 Blue Jays were banded and 75 returns taken.” This gave further evidence to Dan of the species “spectacular increase” over his more than four decades of banding. He reports that the “overall ratio of returns and recoveries to banded Blue Jays is 13.5%. comparable to my total ratio of 14% for 15,586 birds banded during 49 years.”
Dan noted three recoveries of his banded Blue Jays that “add a little more complexity of the Blue Jays seasonal occurrence.” One bird, captured and banded by Dan at Mohonk on 3 September 1961, was recovered two months later on 4 November by a hunter in Alabama, some 900 miles southwest. Another, banded at Mohonk in January 1963, was recovered 15 months later, about 130 miles away in eastern Pennsylvania. And, a third, banded by Dan at Mohonk in August 1966 was found dead at the end of December 1967 near Rochester. Also, reinforcing individual Blue Jay movement, one bird banded in Litchfield, Ct., on 19 May 1975, was recovered by Dan at Mohonk, some 50 miles from Litchfield, on 26 April 1976, and after spending seven months in the vicinity of Mohonk, was captured again by Dan on 1 December 1976. This suggested to Dan “that Blue Jay movements are irregular, perhaps related to food.”
In looking at the Blue Jay population change at Mohonk, Dan surmised that major forest change, in the total loss of the American Chestnut mast crop, due to imported blight which was already killing trees at Mohonk in 1912/1913, was finally only replaced with abundant oak mast some 30 years later. Dan felt this “interval would be about right to give a quantity of acorn production,” providing a major mast food source for species like the Blue Jay. He also felt that, like Cowbirds, an increase in Blue Jays “in the late 1950’s “suggests to me the hypothesis that the elimination of Peregrine Falcon predation during that decade may have been a factor that precipitated the change for both species.” Dan didn’t think “that bird feeders had an influence, as they may have in the parallel Cowbird increase.”
Today, the population of Blue Jays in the Shawangunks seems to have continued to increase, at least seasonally, as evidenced from local feeder watch data and from 67 years of Mohonk Preserve’s participation in the Audubon Christmas Bird Census, following a morning and afternoon route established by Dan in 1950. From 1950 to 1976, Dan found the annual winter bird census averaged about 6 Blue Jays per count day. From 1996 to 2010, the census averaged over a dozen Blue Jays per count day. As Dan concluded, “the population has stabilized near the high level, with minor fluctuations.”
Read the report: Blue Jay. October, 1977. Daniel Smiley.