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Learn About...
The Fraser River Estuary near Vancouver, British Columbia
was officially declared a
Hemisphere Reserve of the
Western
Hemisphere Shorebird Reserve Network
(WHSRN) in December 2004. The reserve includes the
intertidal portions of Sturgeon Banks, Roberts Banks, the
South Arm Marshes, and all of Boundary, Mud and Semiahmoo
bays.
The Fraser River Estuary Hemisphere Shorebird Reserve
encompasses beaches and marshes that support over 50
species of shorebirds.
International Travelers
In April, the last of winter storms drain their fury
across the Fraser River Estuary. But carried on the
southerly winds that lash at marshes and mudflats is a
million tiny shorebirds. Their journey to the Fraser began
one month earlier on warm beaches thousands of kilometres
to the south.
The stirring urge in the hearts and minds of three million
western sandpipers began in February and March on warm
mudflats in Mexico, Central and South America. But the
strong urge to reproduce required a journey that would end
in western Alaska only after high endurance flights across
more than 70 degrees of latitude. Across desert, mountain
range, along Pacific shores flew flocks of
sandpipers.
Assisted by southerly tailwinds they arrived on the Fraser
River Estuary tired and hungry.
Not a month goes by when shorebirds are not on the Fraser
River Estuary. When the western sandpiper departs for the
Alaskan tundra, killdeer, spotted sandpipers and black
oystercatchers will be settling on eggs along the shores
of the Fraser. They will be tending their young when the
first western sandpipers arrive in late June on the way
south after breeding. In August, scores of species from
across the western Arctic, the boreal forest, Yukon
mountains, Siberia and the heartland of British Columbia
will slip out of the air to spend a few days on the
estuary. In autumn, the dunlin arrives in choreographed
flights in flocks that rival the exhilaration of the jet
engine roar of a passing flock of a hundred thousand
western sandpipers. Dunlins will remain on the estuary for
the winter and depart as the western sandpiper returns in
spring.
The wealth of the shorebird community on the Fraser River
Estuary is measured in its number of species and their
abundance. Sandpipers, dowitchers, plovers, yellowlegs,
curlew and others know the Fraser River Estuary. About one
quarter of the world’s 212 species have been seen on the
Fraser River estuary. More than 500,000
western
sandpipers, 60,000 dunlins, and three thousand
black-bellied plovers can be seen on some days. Other
species occur in smaller numbers but many are widespread.
All shorebirds rely on the abundant food produced in the
estuary and farmlands to continue a journey to countries
throughout the western hemisphere.
Marvels of Migration
Each tiny sandpiper requires immense amounts of food to
power flights across the 12000 kilometer one way trip
between breeding grounds and winter quarters. They must
also have sensitive navigational aids on board to navigate
the flight and they must have finely tuned senses to avoid
the dangers along the way.
Migratory flights of shorebirds often include non stop
journeys of hundreds and sometimes thousands of non stop
flying at elevations of up to three kilometres above the
Earth. There the birds catch the steady flow of winds that
can double their ground speed. The flights require a great
deal of fuel. It is not uncommon for small shorebirds to
carry up to 50% of their lean weight as fat stored beneath
the skin to power the journey. In the hand, the yellowish
hue of the fat glows through the birds skin. Each leg of
the migratory journey expends huge amounts of this fat and
in some cases the birds will burn muscle so that they
arrive emaciated and tired. Sleep is a priority and the
birds tuck the head beneath the wing for a few moments of
rest. Then they are off along the beach in search of food.
Tiny worms, clams, small fish and microscopic life on the
mud surface are on the menu of the 50 species of
shorebirds on the Fraser River estuary. Ravishingly
hungry, the birds set about pecking and probing in a
frantic search for food. The winds will be favourable soon
and those that can replenish the spent fuel in time will
launch a flight that will take them 1000 or more
kilometres to the north.
While the shorebirds are busy finding food, their
predators are searching for them. Spring brings large
numbers of peregrine falcons to the estuary. Unsuspecting
sandpipers are their quarry. The peregrine begins its
attack over a kilometre from the flock of shorebirds. They
gain speed and streak across the beach often springing out
from behind marshes or the dikes. A thousand tiny screams
go out as the falcon flashes through the flock. In the
whirring of wings and cacophony of shrieks, the sandpipers
instinctively bunch together in a tight flock able to
dodge most falcon attacks. Nine times out of ten, the
sandpipers escape but on the one occasion, the falcon
snatches an unsuspecting sandpiper from the ground or a
split second after take off.
At least half a dozen times, a sandpiper will stop on
migration to refuel and be pursued by falcons. Those that
successfully run the gauntlet reach the tundra breeding
grounds where parenting begins anew. In a month or more,
they will be returning south for the winter quarters and
the game of life and death plays out once more along the
Pacific shores.
Sandpipers fuel
their lives on a diet of invertebrates caught in the sand
and mud beaches, marshes and in the soil of farmlands.
Most of these tiny animals go unnoticed and carry
unfamiliar names – polychaetes, tanaids, corophium to name
but a few. But these humble abundant creatures are the
critical link in the lives of shorebirds along the Pacific
Coast. The tiny animals eat tiny decaying particles of
plant leaves drifting out of the marshes, on plankton
floating in on the tides, and creatures in soils enriched
by farmers tilling the land. Up and down the coast, the
great migrations of shorebirds depend on a network of
sites with similar rich intertidal mud and marshes that
provide food for their journeys. The lives of the world’s
most travelled vertebrates are entwined in the ecology of
beaches reaching across the hemisphere.
When and Where to See Shorebirds on the Fraser
One or more species of shorebird is always present on the
Fraser River Estuary but the best time to see a variety of
species is in August. Late April and early May is the best
time to see large flocks of sandpipers. Arrive on a rising
tide so that the birds are brought closer to you. Use
binoculars and telescopes to get close views - these birds
require time to rest and feed. A local bird checklist will
help narrow your choices in a field guide. Some of the
sites along the Fraser River Estuary are regional parks or
wildlife lands that cater to people but many other areas
are privately owned lands requiring permission to use.
Please consult a map and show appropriate courtesy.
Blackie Spit
The brackish lagoon at the mouth of the Nicomekl and the
broad mudflats in Mud Bay have long been known to be among
the best places to search for shorebirds on the Estuary.
Large shorebirds such as curlews, godwits, yellowlegs and
dowtichers seem to like this area of the estuary. Many
rare species have been recorded from Blackie Spit. Watch
for willet, long-billed curlew, and marbled and hudsonian
godwits.
Serpentine Fen
The grassy habitats and sloughs are a draw for golden
plovers, buff-breasted sandpiper, ruff and sharp-tailed
sandpiper. In winter, dunlin and black-bellied plover use
the mudflats and fields. Thirty-two species have been
recorded fromt eh Fen.
Mud Bay
Black-bellied plover, short-billed and long-billed
dowitcher, western sandpiper and dunlin are found
regularly in the Bay. The roost at high tide between the
mouths of the Nicomekl and Serpentine rivers and along the
northern shore of Mud Bay.
88th Street Pump Station
Midway along the shore dike of Boundary Bay is a pump
station. It can be reached by car along 104th
or 88th Avenues. The discharging water draws
yellowlegs, dowitchers, western and least sandpipers, and
many other species.
Beach Grove Lagoon
Just of 12th Avenue in Tsawwassen is a small
tidal lagoon that next to Blackie Spit is one of the best
places to see shorebirds. Western, least semipalmated
sandpipers are freqnetly seen and a few red-necked
phalaropes seem to like this place. If lucky you might
spot a sharp-tailed sandpiper, ruddy turnstone, or a
solitary sandpiper. Thirty-five species have been recorded
at the lagoon and on the nearby beaches.
Farmlands
The farmlands near 64th, 72nd and
112th streets in Delta are used by
black-bellied lpovers, golden plovers, dunlin,
buff-breasted sandpipers, whimbrels, and western and least
sandpipers. Tilled soils, newly planted fields and
pasturelands seem particularly attractive in winter. In
summer, killdeer breed along the roadways and farm edges.
BC Ferry Terminal and Jetty
The black oystercatcher was a rare visitor to the Estuary
until about a decade ago when a pair took up residency on
the jetty. Two pairs are now present. Nesting occurs along
the west side of the jetty. Also present on the mudflats
are large flocks of dunlins in winter, western sandpipers
and yellowlegs during migration and if lucky you might
spot some rare species such as marbled godwits. Take care
to park off the jetty. The pilings of the ferry terminal
is the only reliable place on the estuary to see black
turnstones and occasionally a few surfbirds and rock
sandpipers. They are best seen from the ferry while in
dock.
Brunswick Point
This area more than any other is the place to see the
great flocks of sandpipers. In late April or early May,
the rising tide brings in tens or hundreds of thousands of
sandpipers scurrying along the mud. In winter, dunlin and
black-bellied plover are seen here. Yellowlegs and
dowitchers are also present in small numbers on migration.
Do not venture on to the soft oozy mudflat.
George C. Reifel Migratory Bird Sanctuary
The Sanctuary is a must-see destination for budding and
advanced birders. The ponds are used by a suite of common
species – western and least sandpipers, dunlin,
short-billed and long-billed dowitchers, greater and
lesser yellowlegs. This is also the most reliable place to
see sharp-tailed sandpipers. Many rarities have shown up
here and the staff of the sanctuary can let you know what
has been seen recently. Thirty-nine species have been
recorded at the Sanctuary.
Iona Beach Regional Park
The ponds and adjacent beaches have drawn large numbers of
shorebirds and birdwatchers over the years. The flocks of
western and least sandpipers, dunlin, black-bellied
plovers, yellowlegs, and dowitchers attract rare species.
Many Asian species such as spoonbill sandpiper, far estern
curlew, and curlew sandpiper have been seen here. As of
2002, 47 species had been recorded at Iona.
Ecology of the North Pacific Ocean
Some theory about the abundance and
diversity of ocean life
Marine
ecologists have found two theories especially appealing to explain
the abundance and diversity of ecosystems. Top-down dynamics,
also known as trophic cascades theory, supposes that the action of
predators dictates the abundance of prey. Bottom-up theory
imagines that it is the availability of nutrients that determine the
abundance of prey. ‘Top-down’ and ‘bottom-up’ refers to the
theoretical level of predators and their prey on a trophic pyramid.
Trophic level is a group of organisms that derive their food energy
from the same source. For example, plants are generally considered
to be primary producers since most get their energy from
photosynthesis. Producers far outnumber the consumers and even more
so the predators. 
In top down
ecosystems, some predators are thought to have a great impact on the
presence of other species. These predators are known as keystone
species and changes in their abundance can have a cascade effect on
many other animals in the ecosystem. (As an aside, ecologists have
begun to debate the validity of the keystone species concept because
it is not clear when a species should or should not be considered a
keystone.) Two well-known examples of a keystone is the
sea otter and
ochre sea star whose presence
dictate the abundance and presence of many rocky intertidal
organisms. Top-down processes are thought to control intertidal
ecosystems.
Bottom-up theory
suggests that it is the abundance and availability of the organisms
that provide food for the grazers that determine the abundance of
predators. The Pacific Coast of North America lies within a nutrient
enriched shore that derives its nourishment from nutrients drawn to
the surface waters by a process known as upwelling. Cool enriched
waters from the ocean depths are drawn upward to replace surface
waters pushed offshore by winds. Plankton bathing in the rich
surface waters bloom in abundance setting of a chain of food for
everything from other plankton to fish eating whales.
Both
top-down and bottom processes are at work in the oceans. The removal
of the sea otter from Pacific Coast beaches and the collapse of
fisheries during El Nino years are examples of these respective
processes at work.
Further Reading
Butler, R. W. 2003.
The jade coast: ecology of
the north Pacific Ocean. Key Porter Books, Toronto.
Mills, L. S. Mills, M. E. Soule and D. F. Doak. 1993.
The keystone-species
concept in ecology and conservation.
BioScience 43: 219
Power, M. E. and L. Scott Mills. 1995.
The keystone cops meet in
Hilo. Trends in Evolution and Ecology 10:182.
Thorne-Miller, B. 1999.
The living ocean. (2nd
edition). Island Press, Washington D.C.(written July 2004)
Books by
the Foundation Directors
 The
Jade Coast
is an easy-to-read explanation of the connections of
life in the north Pacific Ocean. It begins by explaining
some basic ideas in ecology - how wind and weather
trigger seasonal enrichment of the ocean, the roles
of predators in dictating the presence or absence of
species, and how sun and moon create tides. Then the
reader is taken on a journey out to sea to understand
the workings of life in the ocean. The journey leads
to rocky headlands, along sand beaches, over mudflats
and finally enters river estuaries. Along the way,
connections between the lives of the wonderfully bizarre
creatures that inhabit the shores are explained among
personal anecdotes from 30 years of research. The
Jade Coast by Robert Butler, Key Porter Books,
2003, 176 pages.
 The
gray whale migrates 8000 kilometers from breeding
grounds in Mexico to feeding grounds in Alaska.
Relentlessly hunted in the past, the species eastern
Pacific population was thought to be at risk of
extirpation. Its recovery is a conservation success
story. Jim Darling's book introduces the reader to the
gray whale in nine chapters that include descriptions
of its behaviour, population sizes, migration timing and
routes, summer behaviour, and interaction with humans. 'Gray
Whales' by Jim Darling, WorldLife Library, Voyageur
Press 1999, 72 pages.
The great
blue heron has become an icon for wetland conservation
in North America. Along the coast of the Pacific
Northwest, a subspecies of heron resides year round.
The Great Blue Heron includes a decade of research
on this subspecies of heron following it around the
year. The Great Blue Heron
by Robert Butler, University of British Columbia Press,
1997, 167 pages.
Wild Whales
is a window into the lives of three populations of
whales: killer whales in the Pacific Northwest,
gray whales along the North American west coast, and
humpback whales in the North Pacific. These whales are
some of the best know to science and much of our
generalized understanding of whales in their natural
habitat can be traced back to studies of these species.
Wild Whales by Jim Darling with a foreword by
Gregory Peck, West Coast Whale Foundation publication,
1987, Distributed by Whitecap Books, Vancouver,96
pages.
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