December 2017

Field Notes: Massachusetts’ Oldest Bald Eagle Died Too Young

Fri, 01 Dec 2017 00:00:00 GMT

It turns out that W02 was an important bird in the history of Bald Eagle restoration in Massachusetts. The first wild-born eagles in Massachusetts in modern times were three chicks hatched in two different nests at Quabbin Reservoir in 1989. The banding of the single chick, W01, in a nest in a large white pine in Quabbin Park was the center of a major media event. The same day, two additional chicks, W02 and her sibling W03, were banded with no fanfare in a nest in a red oak tree on Russ Mountain, an island off the east shore of the Prescott Peninsula. The father of these two chicks was seven-year-old Ross, one of the first two eagles raised on the hack tower at the mouth of Egypt Brook on the east side of the Prescott Peninsula in 1982. Both of these first two birds had been taken from wild nests in Michigan. The mother of W02 was a four-year-old bird taken from a wild nest on Cape Breton Island, Nova Scotia.

In 1992, as a three-year-old, W02 found a mate and the pair constructed their first nest on top of an old Red-tailed Hawk nest in a large cottonwood tree near where the Mill River enters the oxbow. The following year she laid her first eggs and fledged two chicks, W29 and W30. In a stroke of coincidence, one of W02’s first two chicks, W29, was also killed on a road this spring. She was found dead at the intersection of Main Street and James Street in Holyoke on March 4, 2017. At the age of 24, she was our second-oldest documented eagle, the daughter of W02 from our first cohort of wild-born chicks, and the granddaughter of Ross who was a member of the first cohort of founding chicks in our restoration program.

During the 24 years of W02’s reproductive life, she occupied five different nests and successfully fledged 19 chicks during 13 successful seasons, which amounts to 1.5 chicks per successful year. However, her nest failed in 11 years, reducing her overall productivity to 0.8 fledged chicks per year. She failed to raise chicks 45.8 % of the time. In the 11 failed years, the nest collapsed in three years (twice with a chick and once with eggs), she failed to hatch the eggs in four years (probably due to cold, rainy weather), she lost chicks in three years, and in one year the circumstances of failure are unknown. After she was killed, her twenty-fifth clutch of eggs was left unattended and failed to hatch. This high rate of failure is probably not unusual.

None of the original 41 eagles brought to Quabbin Reservoir as founders of our modern population are known to still be alive, so at 28 years old, W02 is presumed to be our longest-lived Bald Eagle so far. Having been struck by a vehicle, her death was premature, so the question is, how long could she have lived? The oldest wild Bald Eagle on record was 38. This bird died on June 2, 2015, in Henrietta, Monroe County, New York, surpassing the previous longevity record by five years. She had hatched in a wild Minnesota nest and was brought to the Montezuma National Wildlife Refuge in New York to be raised on a hack tower in the second year of New York’s extensive Bald Eagle restoration program. But she too was killed on a highway by a vehicle, so the question of how old a wild Bald Eagle can live remains unanswered.

For more information on the recovery of the Bald Eagle in Massachusetts, see:

French, Tom. 2016. The History of Bald Eagle Decline and Recovery in Massachusetts. Bird Observer 44: 398-407.

Field Notes: Whip-poor-will Ground Display

Fri, 01 Dec 2017 00:00:00 GMT

It is not uncommon to see Whips on the ground at night, but one of these birds was engaged in a peculiar display. Standing erect with head down, the bird had its wings spread wide, underwing facing us, advancing in tiny hops toward the other bird. The effect was comical, very odd, and somewhat reminiscent of something out of a vampire movie. We assumed that we were watching courtship behavior, though neither of us had ever seen these moves before. We could not identify the gender of either bird. This behavior lasted about five minutes while we were unsuccessfully attempting to extract a camera from the back seat. Finally the birds moved off into the scrub and out of sight.

At home, we dove into the literature. The species account in The Birds of North America (Cink, et al., 2017) suggests that little is known about courtship displays in this species:

Anecdotal accounts by three authors present three different versions of the event, all three of which were observed in same evening in Kansas (DLC). Female may solicit attention of the male perched above her by strutting on ground with wings and tail outspread and head lowered. Female may rock side to side as she walks, circling first in one direction then the other, producing a guttural chuckle (soft popping sound) as she moves (Coale 1920). Male may respond by approaching the female on the ground (or along a tree branch or downed log), raising and lowering his body in a “sort of undulating” manner (Bolles 1912). Male may circle female and she, in turn, moves her body up and down and/or quivers her wings (Fuller 1960). . . . Male may approach female using Tail-Flashing display in which bird hovers in place with tail fanned maximally and showing all of white on retrices (CLC).

Our observations contain some of the disparate elements mentioned above: a displaying bird advancing—“strutting” might not be the right word—on the ground with wings outspread and head lowered, and moving to the right and left—not really “circling”—as if herding the other bird. The displaying bird’s holding of its wings to display the underwings continuously seemed a new feature. Since both birds were on the ground, perhaps a Tail-Flashing display was precluded.

It was a most interesting end to a very pleasant evening program.

References

Cink, C.L., P. Pyle, and M.A. Patten. 2017. Eastern Whip-poor-will (Antrostomus vociferous). The Birds of North America (P.G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from https://birdsna.org/Species-Account/bna/species/whip-p1 on 6/25/2017.

Field Notes: The "Dinner’s Ready" Call of the Barred Owl

Fri, 01 Dec 2017 00:00:00 GMT

Once the young fledge there is a second, much softer call that the female uses, when she has a food item, to locate the young and assess their level of hunger. I alluded to this call in the article, but was unable to describe it clearly, except to say that it started with a variant of the "listless Sora" call and had a different ending. This year, under extraordinary circumstances, I heard this call and can describe it.

The call is soft as it is only meant for the youngsters, who are all within a hundred meters or so. There is no point in attracting potential predators, like a Great Horned Owl. This year I was standing within six meters of the female who had just obtained a prey item. The young were in the trees above and around us. She called four times in quick succession. The call began with the Sora thing and then ended with a sharp EEK, reminiscent of the call of the Rose-Breasted Grosbeak. There was no opportunity to record the call and the situation did not recur.

The purpose of the call is to locate the young, who responded immediately with a hiss. The strength of the hiss probably indicates the hunger level. At any rate, the female went off and fed just one of the young.

This call is somewhat academic since humans are unlikely ever to hear it. Unlike the admonition call, which humans can hear for perhaps a few hundred meters (and owls much farther), the "Dinner's Ready" call is not audible beyond a hundred meters, and most female owls would be reticent to call in the presence of a human intruder. But in this case, we're old friends.