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North Brother Island: Haven for Herons
by Michelle Ashkin
It's a windy, chilly morning in mid March, but the
volunteers who wait at the dock for the boat are a
hardy and dedicated bunch. They have come to
participate in a pilot project on North Brother
Island, an abandoned, uninhabited green oasis north
of Manhattan in the East River, to restore vital
habitat for a recovering population of New York City's
newest avian inhabitants, the harbor herons. The
herons returned to this region in the early 1970s
after a long absence. Now, the uninhabited islands of
New York Harbor offer a sanctuary for these beautiful
birds and an opportunity for their populations to
thrive.
The only way to access the shore of North Brother is
by kayak or canoe. The thirty-four foot power boat
that has ferried today's group of volunteers is owned
and operated by Justin Dambinskas who donates his time
and his boat to assist the NYC Parks Department in
projects such as this one. After negotiating the
strong current and the incoming tide, the boat is tied
off to the wood piling remnants of the old ferry
terminal, whose rusted skeleton still stands. The
volunteers board a small canoe and paddle their way
to the sandy shore eagerly anticipating the work that
lies ahead.
North Brother Island, once the home of a hospital for
patients with highly contagious diseases (including
the infamous Typhoid Mary), is designated as an
Important Bird Area in New York State and is targeted
as an ideal refugia for black crowned night herons
(Nycticorax nycticorax) and other species of
long-legged waders. Several species have already
established breeding colonies in neighboring South
Brother Island, but on North Brother it is primarily
the black crowned night herons that occupy the
available breeding habitat along the south and east
edges of the island.
The goal of this project, managed under the auspices
of the NYC Parks Department Natural Resource Group and
funded by a grant from NY Audubon (through the
National Fish and Wildlife Foundation), is to reclaim
three one-acre plots in areas of North Brother Island
now dominated by invasive Norway maples and kudzu
vine, and replace them with native species such as
box-elders, gray birch and hack-berry that provide
prime nesting habitat for these shy, gregarious,
disturbance-intolerant birds.
To transform the landscape the invasive Norway
maples must be felled, the areas cleared, and
thousands of native saplings planted. Volunteers
from NYC Audubon are joining Project Manager Tim
Wenskus and Chief Naturalist Mike Feller, both of NYC
Parks Department Natural Resource Group to assist in
this effort. By the time volunteers arrive at the
recovery area it is littered with stumps of newly
fallen trees, a sight that might otherwise be a sad
one but for the fact that these trees are highly
invasive and out-compete any native species.
Herons do nest in trees, as well as in scrub and vine
cover closer to the ground. In multi-species colonies
the larger birds such as the great egret will nest
higher up, and the smaller birds, such as the black
crowned night heron, lower down. However, because the
internal branching structure of the Norway maple does
not afford adequate support for the large nests, these
trees are not suitable and must be removed.
Armed with
chain saws and donned in protective orange head gear
and goggles, the morning crew from the parks
department and the Bronx River Alliance, a non-profit
organization volunteering its time, have already cut
down scores of maples, In their place, the 2-3 foot
hack-berry, box elders and gray birch stand like
sentinels guarding newly acquired territory. When this
work is completed approximately 3,000 of these native
plants will occupy the designated sites.
The volunteers cart and carry the saplings to the
newly opened areas and plant them four feet apart. The
plants are small and leafless, but it is not difficult
to envision the day when this sparse, bare, area is
transformed into a thick, multi-layered mosaic of
native flora.
While it will need on-going monitoring
and management to ensure that the Norway maples don't
take over again, this restoration project promises to
provide the perfect nesting habitat for black crowned
night herons other members of the Ardeidae family
seeking refuge on these undeveloped islands surrounded
on all sides by one of the most highly urbanized
environments in the world.
• Click here to read an article on North Brother Island from the Times Online
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