We’re standing near the lakeshore at Kaiser-Manitou Beach Banding
Station, roughly 15 miles west of Rochester
We’re standing near the lakeshore at Kaiser-Manitou Beach Banding Station,
roughly 15 miles west of Rochester. In front of me, Dr. John Waud, professor of
environmental science at Rochester Institute of Technology, gently extricates a
bird – a brown, spotted thrush called a veery – from the fibers of a tall mist
net (which looks something like a volleyball net with fine, almost invisible
mesh). The veery in Waud’s hand, along with scores of other birds, has flown
across Lake Ontario in the dark of night and was captured at the banding
station, which is run by a cadre of volunteers associated with the nonprofit
Braddock Bay Bird Observatory.
Volunteers at Braddock Bay use mist nets to monitor the passage of songbirds
during spring and fall migrations. In the last decade alone, they have tagged
98,000 birds from approximately 130 species. They place a tiny band around each
bird’s leg, record its physical condition, and then release it. When banded
birds are recaptured – either by this crew or by another banding team in its
flight zone – a picture of bird migration starts to develop.
Elizabeth “Betsy” Brooks, long-time bander and co-founder of the
Braddock Bay Observatory in 1985, estimates that she has banded more than
80,000 birds in her lifetime. After handling that many birds and tracking their
movements, she knows a little something about the miracle of migration. She
especially knows the challenges faced by a tiny songbird as it crosses Lake
Ontario during its migrational sojourn.
“On October mornings,” she says, “I’ve seen scores of
ruby-crowned kinglets dripping off the tree limbs and blanketing the ground,
weak and exhausted having just been caught over the lake in a squall.”
Crossing Lake Ontario is just the first obstacle for most birds. For many
species, migration is a transcontinental, transoceanic event that stretches
down to South America. To survive this trek, birds must find safe places all
along land routes where they can rest and bulk up on a high-energy,
high-protein diet of berries and insects. Ecologists call these safe zones
“migratory stopovers,” and studies show that in North America’s
increasingly fragmented landscape, a shortage of stopover habitat is
contributing to population declines in migrating landbirds.
In lakefront communities like those surrounding Rochester, a shortage of
stopover habitat can be especially challenging for birds migrating from Alaska
and Canada. As a result, the Central and Western New York chapter of The Nature
Conservancy has teamed up with a group of scientists for a study to identify
local migratory stopover sites in the region, with the goal of eventually
safeguarding the sites and the birds that depend on them.
The 5 billion-bird march
This fall, more than 5 billion birds will migrate across North America, each
traveling a semi-predictable flight path between its breeding and wintering
grounds, each requiring quality stopover sites between flights. Despite how
masterfully engineered these tiny flight machines are for migration, studies
show that some species, especially the fast-declining group of neotropical
migrants that winter from Mexico to South America, can experience up to 85
percent mortality during their annual treks. Considering that a migratory bird
spends nearly one-third of its year traveling between its breeding and
wintering grounds, there’s ample opportunity for danger.
Most birds migrate under the cover of night using tailwinds to boost their
flight. Navigating by the stars and by the earth’s magnetic field, birds dodge
an incredible number of obstacles. If not eaten by a hungry hawk or owl, they
may fall victim to plate-glass widows, cell-phone towers, or turbines on wind
farms.
After flying hundreds of miles in a single night, lean and weary birds seek
refuge, sometimes desperately, in woodlots, backyards, orchards, and wetlands
where they can rest and refuel for the next leg of their journey. This
hopscotch nature of migration makes birds highly dependent on quality stopovers
that need to be strung out in regular occurrence along routes that cross
thousands of miles.
Astonishingly, many birds return to the same backyards repeatedly over their
life spans, a navigational phenomenon called site fidelity. “A bird’s
ability to fly hundreds or thousands of miles only to find the exact same feeder
over and over again just blows my mind,” says Betsy Brooks.
Clearly, then, the key to conserving bird populations is to protect habitat,
not only where they nest each spring and where they hunker down in winter, but
in the multitude of migratory stopovers along their flyways.
Rochester’s migration scene
The Rochester region – indeed, most of western New York – plays an important
role in bird migration for two reasons. First, we are located in the Atlantic
Flyway, one of only four major migration routes in North America. The Atlantic
flyway cuts a broad swath across Canada, funnels through the Great Lakes, hugs
the Atlantic shore and continues toward the Gulf of Mexico and beyond.
Our location on the southern rim of Lake Ontario is also critical.
“Lake Ontario presents a significant milestone to migrating birds,”
says David Klein, senior field representative at The Nature Conservancy Central
& Western New York. “Birds tend to ‘pool up’ on either side of the
lake just prior to, and after, crossing.”
In fact, avid bird watchers depend on this fact. Bob Spahn, who has birded
the Rochester area for more than 50 years, combs small woodlots along the
lakeshore during spring and fall where, he says, “birds tend to pass in
clumps and bursts.”
Birders refer to this as “migrant fall-out,” and find reliably
good numbers and kinds of birds in lakeside habitats such as Island Cottage
Woods Preserve, Durand-Eastman Park, and Hamlin Beach State Park. Some sites
further inland, such as Cobbs Hill Park and Letchworth State Park, are also
migrant hotspots, especially during spring.
Using his eyes and well trained ears, Spahn ticks off every bird he observes
onto a card or neat checklist; his New York state bird total hovers near 386
species, out of a possible 470. Spahn finds it more challenging to identify
songbirds in fall, since at that point birds no longer sing to attract mates,
and their colorful breeding plumage has molted to a winter drab, allowing the
birds to elude predators and focus their energies on flying.
When birds arrive on the southern lakeshore, particularly after storms, they
are fatigued and hungry. Therefore, undeveloped areas on the shoreline of Lake
Ontario, and to an unknown degree farther inland, are critical pit stops for
migrants.
But what makes a quality stopover site? How far inland do they occur? And
how might these stopovers, which occur on patchwork of public and private
lands, be protected?
Large, expansive wetland complexes, such as Montezuma National Wildlife
Refuge and the 17-mile stretch along the eastern shore of Lake Ontario, are
well known stopovers for migrating waterfowl and shorebirds. They have been
protected accordingly.
But studies show that a small, isolated woodlot in the middle of a farm
field or a small patch of woods in the city (think Rochester’s Washington
Grove, or Central Park in New York City) can be just as vital to migrating
songbirds – such as robins, wrens, warblers, thrushes, kinglets, and orioles –
as long as they have abundant cover, insects and fruiting shrubs or trees.
Surveying the local bird scene
But how small is too small? How isolated is too isolated? To address these
questions, staff from The Nature Conservancy has teamed up with scientists from
Audubon New York, New York State Department of Transportation, and five area
universities (both Klein and Waud are on this team). This study, funded by the
New York Department of Environmental Conservation, is part of a broader Nature
Conservancy effort to identify and preserve important wildlife habitats in the
Great Lakes’ coastal zones.
After examining the scientific literature, the team identified three of the
most important characteristics for stopover sites and developed a predictive
model using remote-sensing and GIS (Geographical Information Systems)
technology. The team is testing its model on 21 study plots located on a
mixture of private and public land from Aurora to Syracuse.
During the next several migration cycles, experienced volunteer birders –
including Spahn and others who can identify approximately 90 percent of birds
by sight and sound – will walk these study plots and tally each bird they
observe. Birders will submit their counts to team leaders, who will analyze the
data and enter them into eBird, a continent-wide database of birds developed by
Audubon and the Cornell Lab of Ornithology.
If predictions are on the mark, volunteers will observe a high number of
migrant songbirds in plots that are closer to the lakeshore, feature woody
cover within 5 kilometers of the site, and retain high habitat diversity. With
this confirmation, scientists would able to use remote-sensing technology,
rather than labor-intensive field studies, to analyze where quality stopovers
occur.
This three-year study will result in a map of regional stopover sites and a
set of guidelines that can be used by landowners, governments, and land trusts
to help them make informed decisions on how to protect migratory stopovers. The
study will also help organizations prioritize spending on land conservation
projects that protect bird populations.
“Migration presents an exciting but fragile time in a bird’s
life,” says Betsy Brooks. “One wrong move and a hawk has it in its
talons. One sudden sleet storm over Lake Ontario and a migrating kinglet drops
exhausted and drowns. A young gray catbird banded here in Rochester can be
found dead a week later on an oil platform in the Gulf of Mexico…”
But as long as these tiny winged creatures are still flying, Brooks and
dozens of other citizens will keep watching birds, banding birds, counting birds,
and sharing their observations. And by doing so, they will help keep a pulse on
the planet.
For more on the migratory stopover study, visit nature.org/cwny/migratorystopovers.
Why protect birds?
Native birds have been protected under federal law since the passage of the
Migratory Bird Treaty Act of 1918. Since then, scientific research in the
fields of ecology and conservation biology has generally supported the wisdom
of that act. Here’s why: birds occupy nearly every habitat on Earth and are
considered an ecological indicator species, one that signals early warning of
environmental changes. This means that monitoring changes in bird populations
can alert us to environmental degradation, hopefully in time to reverse its
effects before they reverberate up the food chain and affect human health.
A classic example of this early-warning system occurred in the 1960’s, when
a well documented decline in bald eagles was underway. Toxicological studies
revealed the root cause to be DDT, a widely used pesticide that entered the
food chain and caused chick mortality by weakening the eggshells of female
eagles (as well as osprey, brown pelicans, and peregrine falcons). This
linkage, plus early indications that the substance had significant human health
effects, produced a protracted legal battle that led to a ban of DDT in the
United States and several other countries. After a few decades, bald eagle
populations rebounded and in 2007 they were taken off the endangered species
list.
Birds also benefit from a powerful advocacy. One in five Americans call
themselves a “bird watcher.” Members of this group are no
featherweights when it comes to supporting the economy – numbers from the U.S.
Fish and Wildlife Service show that they pumped $36 billion directly into the
national economy in 2006, through travel, optics, gear, and other expenditures.
Their total economic impact that year was reported at $82 billion.
Another reason to protect birds? Quite simply because, as John Waud puts it,
“Other species have the right to exist. Humans have the intellectual and
physical capacity to drastically alter our environment. With that comes the
attendant responsibility to protect or repair what’s left.” – LK
What you can do
Homeowners can help protect birds in several ways:
Learn to watch birds. October and November are excellent months to observe
the parade of migrant waterbirds on Lake Ontario. Attend one of the free field
trips for beginner bird watchers hosted by the Rochester Birding Association.
Upcoming dates include October 4 at Hamlin Beach State Park and October 17 at
Charlotte and other lakeshore hotspots. Additionally, several experienced and
helpful birders man the “Lake Watch” bird count beside the Lakeshore
Pavilion at Parking Lot No. 4 for a few hours every morning through November.
Bring binoculars or a spotting scope. See rochesterbirding.com for details.
Kill your lawn; go natural, suggests David Bonter, a Ph.D. ornithologist
from Cornell Lab of Ornithology and board member of Braddock Bay Bird
Observatory. Reduce or eliminate your use of herbicides and insecticides. A
perfectly kempt lawn may impress the neighbors, but it’s a sterile environment
that squashes insect and plant diversity. Birds feast on the fat and protein
from spiders, moths, slugs, caterpillars, flies, beetles, and other creepy
crawlies during both the nesting and migration seasons. These insects rely on
many different plant hosts, not on fescue alone. Plus in every season, birds
need the sheltering cover that plants provide.
Plant native shrubs and trees; think berries, adds Bonter. Birds switch from
high-protein diet of insects to one of berries late in the season, so make your
backyard bird-friendly by planting lots of fruit-bearing shrubs and trees.
Dried berries left on fruiting shrubs can also help sustain birds through the
winter. See nwf.org/gardenforwildlife for native gardening ideas.
Put up a nestbox, suggests Tina Phillips of Cornell Lab of Ornithology’s
Nestwatch program. You can help generations of birds successfully raise new
chicks simply by erecting a nestbox or birdhouse in your backyard. In this
area, you might attract bluebirds, wrens, swallows, screech owls, or American
kestrels. Visit nestwatch.org for advice or
to register.
Help monitor birds, says Betsy Brooks, who’s been volunteering her time to
monitor birds for 30 years. No matter what kind of bird watching you enjoy,
from backyard bird feeding to chasing rare birds, there’s a citizen-science
program in place to accept your observations. From seasonal programs (eBird,
Project FeederWatch) to easy, one-day counts (Christmas Bird Count, Great
Backyard Bird Count), casual birders contribute in a significant way to the
collective repository of bird knowledge. For more information, search
“citizen science” at Cornell Lab of Ornithology’s website
(birds.cornell.edu) or contact the Rochester Birding Association
(rochesterbirding.com) about assisting with local surveys.
Join the migratory stopover study, suggests Laura McCarthy, Audubon New
York’s volunteer coordinator. Many volunteers are needed to walk transects and
count birds during the spring and fall migration seasons. If you are an
intermediate to advanced birder interested in lending a hand, your counts can
make a difference. Visit ny.audubon.org.
Support land conservation, suggests Jim Howe, executive director of The
Nature Conservancy. Become a member of or donate to groups that work to protect
habitat, including local land preservation trusts and The Nature Conservancy
(nature.org/cwny). Be vocal. Let your friends know why you support habitat
preservation. Encourage your employer to adopt habitat-friendly policies.
Keep your cat indoors, suggests the American Bird Conservancy. There are
more than 77 million pet cats in the United States, of which approximately 35
percent are kept indoors. Another 60 million to 100 million cats are homeless.
Hundreds of millions of birds fall prey to free-roaming cats each year. It
seems cute when your orange tabby brings you “a little present,” but
cat predation is an added stress to bird populations already struggling to
survive habitat loss, pollution, pesticides, and other impacts. Indoor cats
live longer, too. For more information, visit abcbirds.org.
This article appears in Sep 30-30, 2009.
