Date: 7/14/17 8:40 am From: Paul Roberts <phawk254...> [arlingtonbirds] <arlingtonbirds-noreply...> Subject: [Arlington Birds] Update on Buzz and Belle: The Alewife Redtails July 2017 (Long)
A ³brief² update on Buzz and Bellıs status.
Buzz and Belle nested for the third straight year in a quiet private
residential area of Cambridge, away from 185 and Fresh Pond Mall. All the
information with regard to nesting here is from others who have followed the
nesting closely. Again, I have not visited the nest site for reasons stated
The private neighborhood site Buzz and Belle had used the two previous years
was not available to them this year. It had been purloined by another raptor
that nests earlier than Redtails, and that frequently occupies used Redtail
nests because they do not build their own: Great Horned Owls. The owls did
not successfully fledge young from that nest, but their presence drove Buzz
and Belle (more likely particularly the latter) to find/build a nest several
blocks away in a private neighborhood. The nest did not appear well built or
situated, exposed to wind from photos I saw, but it survived the season.
Only one chick apparently hatched, and it fledged successfully. Its gender
is uncertain, as it is not a particularly large bird or a particularly small
one. The youngster has remained in this relatively densely wooded part of
Cambridge, unlike its older siblings who gradually gravitated to Dadıs
territory around Fresh Pond Mall, and in particular the area surrounding the
RA or radio antenna (tower) off Concord Avenue and Fern Street.
For over two weeks Belle, and to a lesser extent Buzz, have resumed perching
on the RA for good portions of the day, particularly in the morning. They
can almost certainly see the area of their most recent nest and some of the
activities of their fledgling. Today for the first time in a long while, the
two adult Redtails perched together on the antenna on Raytheon. Buzz has
occasionally perched on the Mobil pine, an old haunt. The two adults are now
back in Buzzıs core territory much of the time and are more visible.
Check out the RA carefully. The owner recently added a new FM antenna near
the top, which Buzz and Belle have opted to use as it now provides the
highest good perch on the tower. (The highest perch is usually the dominant
and preferred perch. To perch lower is to allow other raptors to perch above
you and strike at you at will.) It is a chore to fly that high, requiring a
physical effort they might not like to exert every morning, especially
earlier. (Itıs easier when there is a good breeze or thermals.) You have to
look really high.
There have been intruders in Buzzıs territory this year. A pair of Redtails
to the west, the male of which looks very Buzz-like, but it seems as though
they might have nested well west of Raytheon. A second-year Redtail has been
seen occasionally, including recently, once perching on Rindge Towers,
another time on the ³teacups² at the Alewife Brook Rotary at Rte 2/16. The
Peregrines that have wintered on Rindge Towers have been back from their
nest site. Their young (three) have fledged and at least one, possibly more
of them, have been brought over to Fresh Pond Mall occasionally to hunt.
There presence is sporadic, but they still want to control the airspace.
This past week I was watching the adult female Peregrine hunt. Suddenly, she
took off like an air-to-ground missile, rocketing from 22 stories high
towards the old B&M Maintenance Yard west of Rte 16. Boing! She had spotted
a Red-tailed Hawk sitting on a utility pole along the train tracks and
aggressively drove it off. The Redtail appeared to be an adult; at least it
had an essentially bright red tail. It might have been Buzz, but I doubt it.
It might have been the second-year Redtail, who Mark Resendes said recently
now had an almost full adult tail. Whatever, the Redtail rolled over on its
back three times with talons up as the female Peregrine buzzed it, but I did
not see any actual contact. The hawk retreated behind the trees just east of
the Fawcett St apartments where Buzz had once nested. (Weıve not see Buzz in
that area for a long time, but it could have been him.)
It is an open question if Buzz and Belleıs fledgling will be drawn over to
Fresh Pond Mall or will continue to learn to hunt and be increasingly on
his/her own in the quieter, less heavily trafficked nest area.
There are a lot of questions about Buzz and Belle, and urban Redtails. Buzz
is at least 19 years old, and quite possibly several years older than that,
so he is probably in the oldest 1% of Redtails in the universe. Several wild
Redtails are known to have lived to be 27-28 years old, including one in the
Blue Hills of Boston. Second, most raptors that live longer than 15-18 years
are believed to have a significantly diminished capacity to effectively
fertilize eggs. (Think ³Pale Male².) That might explain why the past three
years Belle has had 1, 2, and 1 young respectively. Of course, we donıt know
her age at all, and that could well have something to do with it. I think
there is also a reasonable possibility that she has laid fewer fertilized
eggs because of tension and stress. My impression is that she is relatively
shy, does not much like being around people, and does not like being exposed
in a ledge nest. She has compelled Buzz to expand his territory, and
increased the physical and possibly emotional demands on him, to nest
quietly in a ³relatively² secluded setting in a traditional tree nest.
Extrapolating from human experience, added stress and tension during mating
season can have negative consequences on successful reproduction.
Iım also intrigued because currently there is a lot of new research being
conducted on urban raptors, a relatively new phenomenon. Cheryl Dykstra,
editor of Raptor Research, is editing a book of fascinating papers on urban
raptors that should be out within the next year or two. Redtails, Cooperıs
Hawks, and Great Horned and Barred Owls, have been incredibly successful
exploiting ³new² urban habitats, and these habitats have facilitated or
prompted dramatic changes in behavior, including towards human beings and
each other! Last fall I learned that Northern Goshawks have successfully
moved into cities in Germany. Yesterday I learned they have been breeding
very successfully in urban Finland! Can you imagine goshawks as urban birds!
Whatever, one clear consequence of urbanization is that many Redtails now
find adequate prey in cities year round so they no longer migrate south.
Redtail migration counts are dropping dramatically. Wintering counts are
decreasing in the southern U.S. and skyrocketing in the north. With
adequate prey (squirrels, pigeons, and rats) year round, Redtails might
also be afraid to leave and have someone else claim their territory.
Another change is that with much great population densities in the city than
in the countryside, it is possible for individuals to find mates quicker and
more easily compared to their country brethren; to comparison shop because
you find more floaters in cities than in comparable rural areas, and to find
a floater as a replacement for a suddenly lost mate.(Ask young people from
rural areas about the challenges of finding a potential mate, compared to
those in the city.) It is also possible for there to be more intense
competition for nest sites and mates. Itıs generally believed that most
eagle injuries seen in rehab centers now are not caused by cars, buildings,
wires, or non-injury-induced starvation, but by young adult eagles in their
first active breeding season or two! New technology and the Cooperıs hawk
invasion of cities has enabled researchers to document that in urban areas
where the Cooperıs Hawk population is fairly dense, already mated females
³visit² the nest site of neighboring pairs to check out the territory and
the male to see if either is more attractive than their current ³situation.²
This helps explain the recent discovery that 10-20% of the Cooperıs chicks
hatched do not have the same father. (Sort of gives ³mate for life² a new
meaning.) It appears that with raptors as with human beings, cities are
driving significant changes in behavior.
The urban environment, as we all know, is fast paced and changing rapidly in
many ways. There is significantly less green space or brown ³waste areas²
available to prey and predators around Fresh Pond Mall than there was just
two or three years ago. How many thousand tons of concrete have been poured
into foundations for new apartment buildings, office buildings, and garages?
That might make Redtails more dependent on the old dependables: squirrels,
bridge rats (or bridge falcons, i.e. pigeons), and rats, highly susceptible
Weıve seen the Redtail pairs that nested at Huron Towers and over by
Vineyard Fellowship dissolve and disappear for reasons unknown. (Might be
related to the crash in the squirrel population several years ago, which is
now recovering rather well.)
Who knows what the coming year holds for Buzz and for Belle? Whatever, you
now have a reasonable chance of seeing them on the RA, and perhaps
increasingly on some of their other old haunts.