Nesting and Food-Caching by Sharp-Shinned Hawks
in Ipswich
Jim Berry
In recent years I reported in this journal on five nests of Sharp-shinned Hawks,
Accipiter striatus, in three locations in Essex County, Massachusetts, in the years
2000–2003 (Berry 2000, 2002, 2003). These were the first Sharpshin nests known
from the county since 1896. All were in conifer stands in reasonably wild, protectedplaces.
Another Sharpshin nest discovery, and the most surprising, came in 2006, when apair nested in the woodlot beside my house in Ipswich. This episode began theprevious fall, when David Flood, my neighbor across the road, a busy state highway,
told me he thought a Sharpshin pair had nested near his house, which is surroundedby various conifers. He described these small hawks to me and said they had fledged
two young, and that all four birds were unafraid of people and had even bathed inpuddles with him sitting nearby. I was unaware of this and hadn’t noticed the birds
around that summer — surprising in retrospect because of their various nesting callsthat I had heard many times before. I did, however, see a male Sharpshin harass two
Pileated Woodpeckers in our yard on October 21, 2005, and wondered at the time whysuch a small hawk would chase birds too large to be prey. Through the ensuing winterof 2006 my wife and I frequently saw an adult male Sharpshin at our feeder. When I
began seeing a pair acting territorial beside our house in March, I realized that thebirds reported by our neighbor in 2005 were now holding territory on our side of theroad — and in the case of the male at least, probably without having migrated.
Territorial defense could provide an explanation for his concern about large
woodpeckers in his domain, though these hawks will often harass birds larger thanthemselves. In any event, the woodpeckers did not stay around.
For my wife Natalie and me, the chronology of this amazing nest began on
March 30, 2006, before most migrant Sharpshins had passed through this area. On
that day I saw the pair copulate on a fallen branch very near our house and watched
the female take sticks repeatedly to the same area within 150 feet of the highway. I
soon located the nest, nearing completion even on this early date, about forty feet up
in a young Norway spruce surrounded and soon to be overshadowed by deciduoustrees — ash, maple, and black locust. Choosing such a tree was remarkable in itself,
since Sharpshins normally prefer dense conifer stands, and there are many large whitepines, spruces, and larches in the immediate area.
The chosen spruce was thin and no more than fifty feet high; the large stick nest,
about two feet in diameter and typically huge for the size of the bird, was located justbelow the sparse crown on the north side of the trunk. It was also very close to ourelderly neighbor’s small house. The supporting branches were thin, and from thebeginning the nest looked unstable as it angled down and away from the trunk. Yet it

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Male Sharp-shinned Hawk on territory,Ipswich, 4/30/07. All photographs by PhilBrown.

withstood gales and rainstorms that
seemed interminable that spring. The
larger female appeared to do all thebuilding, unlike the Willowdale State
Forest pair a few years earlier (Berry2003). Though spruce and pine twigs
were commonly available, her preference
seemed to be for live larch twigs, which I
watched her break off several times. I do
not know what she used for the nest
lining. By April 3 she was shaping theinterior of the nest to her body, and thiswent on for the next week.

By mid-April the female wasstanding on the nest a lot. On the seventeenth she began sitting, marking thecommencement of incubation. Bildstein and Meyer (2000), authors of the Birds ofNorth America account, write that Sharpshins, unlike many other raptors, delay
incubation until the clutch is complete or nearly complete, in the manner of songbirds,
so the standing could have meant she was simply protecting the early eggs, which arelaid at two-day intervals, until she was ready to incubate. In keeping with Sharpshin
etiquette, the female did all the incubating (per Erlich et al. 1988 and Bildstein andMeyer 2000, but contra Bent 1937 and Baicich and Harrison 1997).
The male did all the hunting but rarely brought food to the nest for her. Rather, healways called to her when he had caught a bird, a series of rapid, high-pitched kee
syllables, usually twelve to sixteen at a time, the whole phrase repeated several times
a minute. (Remarkably, these food calls are not mentioned in either Bent 1937 orBildstein and Meyer 2000.) The calls were also my signal to get to the scope andwatch the nest, and Nat would alert me whenever she heard them. If the incubating
hawk needed food, she left the nest and took it from her mate, at least once in a
midair handoff and probably routinely by that method, which I have often observedwith nesting Sharpshins. She then ate it as fast as she could before hustling back to
her duties on the nest. This usually took about ten minutes, probably the longest
period of time she was ever off the nest during incubation.
But many times she did not leave the nest when her mate gave his food calls. Hewould keep calling, but if for whatever reason she did not need food, she remained
silent on the nest. Finally, the male would either deliver the food to the nest (observed
only once or twice) or give up calling. I assumed for a while that in such cases hewould eat the prey item himself, but on June 2, during such an incidence, I hurried tothe backyard opposite the spot he usually called from and saw something I have notfound in the literature: food-caching by the male Sharpshin. When the female did notcome to take the prey item, a songbird, he appeared to eat only the brain, after which
he cached the bird in a thicket of dead larch branches fifteen to twenty feet off theground. This was a Eureka moment: the female didn’t need to fetch the foodimmediately if she knew where he cached it and could go get it anytime. And four82

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days later, on June 6, while Phil Brown and I were photographing the nest, she did
exactly that. She left the nest as we were watching and returned within a minute witha food item, almost certainly a cached one because the male had not been giving foodcalls. She then began feeding the young, paying no attention to us.
(Note: I was not able to find food-caching in the literature for Sharp-shinned
Hawks, but see Craig Jackson’s field note in Bird Observer. These may be the firsttwo documented incidences of this behavior.)
Meanwhile, I had seen the female Sharpshin moving a lot on the nest on May 26,
perhaps because the eggs were hatching, though based on an April 17 incubation startand a known incubation period of thirty to thirty-five days, hatching should haveoccurred between May 17 and May 22. I first observed two nestlings being fed on
May 27 when they would have been around a week old. By the twenty-ninth three
young were visible, and by June 5 four
little bobbleheads could be seen, still
downy and all appearing about the samesize. The feeding method had notchanged — the male still announced his
food deliveries, the female went to him
to get the food if she was ready for it,
and then she took it to the nest and fed
both herself and the young, eating
Female and four young Sharp-shinned Hawks
proportionally more of the food herself
on nest, Ipswich, 6/6/07.
when they were little, less of it when
they were bigger. I timed two feedings on May 27, when the young were still small
and the female had to tear the food up for them. Both lasted seventeen minutes. The
young were fed several times a day, sometimes at sunset, though I can’t say whether
that frequency was maintained on rainy days when I made fewer observations. Asstated, I rarely saw the male go to the nest, though he often perched nearby to watch
over it.
All this took place despite constant noise from traffic, power tools, and nearby
construction activity. Nor did these birds evince nervousness at people walking in thewoods near the nest, which happened after our neighbor died and surveyors werehired by the heirs to reestablish the property boundaries. On May 24 a bulldozer
actually cleared part of the land close to the nest tree for percolation tests. That
evening the female was on the nest as if nothing had happened; it turned out that theyoung had probably hatched by that time, which would explain her refusal to abandon
the nest. Until then I had been watching the nest through a scope from the edge of ourfront yard so as to keep well away from it, but from then on I was not hesitant toobserve it from a closer vantage point by the road when foliage made it increasingly
difficult to view from the yard. These hawks were amazingly tolerant of humanactivity — a good sign for the future of the species.
By the first of June the mother did not need to cover the young all the time andtended to stand on the side of the nest if the weather was fair. But most of May andBIRD OBSERVER Vol. 35, No. 2, 200783

early June were rainy, setting records for rainfall in the entire Boston area and causingmajor floods. June 6, the day of the feeding incident mentioned earlier, was a niceday, but after two more days of rain on June 7 and 8, only a single chick was visibleon the nest the morning of the ninth. The male had been a good provider, but
apparently the sustained rain and cold had taken their toll. Perhaps the mother had
been unable to keep them dry through the chilly nights, or maybe the surviving chick
had succeeded in getting more than its share of the food, which in the end could haveincluded its weakened siblings.
Whatever the case, only one of the young survived to fledging. By June 13 it wasgetting its wing quills and flapping them a lot. By June 22, when we returned from aweek away, it was fully feathered except for remnant down on the forehead. Essex
birder Phil Brown had been monitoring the nest for me but had not yet noticed theyoung branching out from it. It must have happened soon after, for on June 25 I saw
the young bird flying and begging foodfrom the adults. It had been on the nest
the previous two evenings but could havebranched and flown before the twentyfifth, since young hawks often return tothe nest to be fed for a week or two afterfledging. As it was, if fledging took placeon the 25th, the juvenile’s age, based on
the latest hatch date figured above (May22), would have been at least thirty-four
The one surviving juvenile Sharp-shinned
days. Most sources (e.g., Erlich et. al.
Hawk shortly before fledging, 6/22/07.
1988; Baicich and Harrison 1997) saythat Sharpshins fledge at anywhere fromtwenty-three to twenty-eight days of age. So something in my calculations would
seem to be wrong, though I did see the female apparently begin incubation on April
17, and she was certainly feeding young before May 27 if I could see them on thatdate. It appears that either incubation or fledging took longer than the times
commonly cited in the literature. The other possibility is that the bird fledged before
June 25, and we simply missed it, though it couldn’t have been much earlier.
We saw the family in flight over the next three weeks, more sporadically as thedays went by. Typically the juvenile, now identifiable as a male by his small size,
would be zooming around with the adults, begging for food and improving his flying
skills. This took a while, because on July 3 Nat saw him crash-land in a tree while
following one of the adults. That same day I watched the female land on a branchwith a prey item and start to pluck it when the juvenile flew in, grabbed the bird, andtook off with it. Both of them called often, the young higher-pitched than the mother(which would be right for a male) and a bit raspier than either adult. We never did see
him receive food in a midair handoff, as has been widely reported for the young of
this species (Bildstein and Meyer 2000), but that could have been due to our lack ofcontinuous observation.

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July 5 was Annoy the Sharpshins Day for the local Blue Jays, but of course they
had been doing that right along. The hawks would chase the jays right back when they
had had enough, and the juvenile seemed to be holding his own with them. We hadfew sightings after that as the young Sharpshin’s skills no doubt improved and thebirds expanded their hunting territory.
Other than the observed food-caching, perhaps the most noteworthy thing about
this nesting event was its timing. Bildstein and Meyer (2000) describe the Sharpshinned Hawk as the “last accipiter to arrive on breeding range in temperate North
America, in April and early May.” No studies cited by them were in New England,
but “In New Brunswick, eggs [are] laid mid-May; young fledged mid-July.” Timingcited from other states was similar, even in the Carolinas, and in some states evenlater. The Ipswich birds were building the nest in March and had completed the clutchby mid-April, making the cycle about a full month earlier than what would beexpected at this latitude. Fledging in late June was a month earlier than the fledging I
observed at three other successful nests in the county described in my previous
articles, from all of which the young fledged in late July.
The reason may be that this pair of Sharpshins wintered in or near the nesting
territory and did not migrate. The evidence is circumstantial but strong: the very
probable nesting by the same pair across the road the year before; the consequent
apparently territorial nature of the male Sharpshin’s interaction with the Pileated
Woodpeckers that October; the presence of an adult male at our feeder through thefollowing winter; the presence and mating of the pair in late March; and theircompletion of the new nest by the end of that month. For the pair to have migrated
here and completed a nest by the time Sharpshin migration is just beginning in New
England is unlikely. Several references suggest that not all Sharpshins are migratory,
but the phenomenon seems poorly known. Alsop (2001) states that “Some migrate,”
while Kaufman (1996) says, “Some in the northwest may be permanent residents, but
most are migratory.” Bildstein and Meyer (2000) call the birds “partial” migrants but
are vague on whether any are nonmigratory. Bent (1937), another comprehensive
source, does not address the question.
In short, I am aware of no evidence other than that described in this article that
New England Sharp-shinned Hawks are at least in some cases nonmigratory. Few ofthem nest in this area, and it seems safe to assume that virtually all wintering birds arefrom farther north. It is a question deserving more attention but difficult to answer
short of tagging a lot of nesting birds, preferably those nesting near the coast.
References
Alsop, F.J. III. 2001. Birds of North America: Eastern Region. Smithsonian Institution: DK
Publishing.
Baicich, P.J. and C.J.O. Harrison. 1997. A Guide to the Nests, Eggs, and Nestlings of North
American Birds, second ed. Boston, New York, etc. Academic Press. Republished in 2005
as Nests, Eggs, and Nestlings of North American Birds by Princeton University Press.
Bent, A.C. 1937. Life Histories of North American Birds of Prey, Part 1. Washington: U.S.
National Museum Bulletin 167.

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Berry, J. 2000. Significant Recent Nesting Records from Essex County, Part 1. Bird Observer
28 (6): 371–77.
Berry, J. 2002. Additional Significant Essex County Nest Records from 2001. Bird Observer
30 (3): 188–200.
Berry, J. 2003. Significant Essex County Nest Records, 2002–2003. Bird Observer 31 (6):337–55.
Bildstein, K.L., and K. Meyer. 2000. Sharp-shinned Hawk (Accipiter striatus). In The Birds ofNorth America, No. 482 (A. Poole and F. Gill, eds.). Philadelphia: The Birds of North
America, Inc.
Erlich, P.R., D.S. Dobkin, and D. Wheye. 1988. The Birder’s Handbook: A Field Guide to the
Natural History of North American Birds. New York: Simon and Schuster.
Jackson, C. 2006. Observations of a Sharp-shinned Hawk Nest. Bird Observer 34 (5):305–08.
Kaufman, K. 1996. Lives of North American Birds. Boston, New York: Houghton Mifflin.
Jim Berry is writing a book on the birds of Essex County and in line with that effort iscoordinating the fieldwork in the county for the second Massachusetts Breeding Bird Atlas
project. Appreciation is expressed to Ted Davis for reviewing a draft of this article and to Phil
Brown for assisting in monitoring the Sharpshin nest and for generously providing the photos
that accompany this article.

SHARP-SHINNED HAWK BY BILL LAWLESS

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