hello tweets,

i just wanted to let you know that the decline in migratory shorebird
numbers has been noted by the general public (i.e.; non-birders --
surely you are related to a few of "those people").

regards,

Deborah Wisti-Peterson, PhD Candidate nyneve at u.washington.edu
Department of Zoology, University of Washington, Seattle, Wash, USA
Visit me on the web: http://students.washington.edu/~nyneve/
Life is better when you are reading a good book -- Author Tim Green



---------- Forwarded message ----------
Sent: Saturday, January 06, 2001 10:17 AM


>
>
> The following article is from The Vancouver Sun newspaper in Vancouver BC,
one of Canada's most respected dailies. Its website is at
http://www.vancouversun.com.
>
> Shorebirds decline a mystery
>
> Populations have fallen off across North America and researchers are
trying to uncover the cause
>
> Larry Pynn Vancouver Sun
>
> Rob Butler, Special to the Sun / A Western Sandpiper's view of Sidney Spit
Marine Park. The Canadian Wildlife Service reports that fewer sandpipers are
counted on Sidney Island each summer.
> Vancouver Sun / (Migration of the Western Sandpiper)
> (Semipalmated Plover)
> (Killdeer)
> (Western Sandpiper)
> (Sanderling)
> From the western sandpiper of the Pacific to the red knot of the Atlantic
and the ruddy turnstone of the Arctic, shorebirds are showing widespread
population declines across North America, according to a Canadian Wildlife
Service study.
> Based on census data as far back as the late 1960s, the study reveals that
28 of 35 shorebird populations on the continent, or some 80 per cent, are in
decline, including 19 showing "statistically significant or persistent
negative trends."
> Counting flocks of shorebirds numbering in the thousands is notoriously
subjective work, but researchers are struck by the consistency in the
declines across disparate regions and in spite of differences in counting
techniques.
> "A bunch of different indices all point in the same direction," said Rob
Butler, co-author of the report and senior biologist at the CWS regional
office in Delta. "This is not occurring by chance."
> Anecdotal reports from amateur bird watchers and clubs have also suggested
shorebirds are in decline.
> Cause of the trend is difficult to pinpoint, since shorebirds can migrate
more than 10,000 kilometres between their nesting and wintering grounds,
with several important fuelling stops en route.
> But potential factors include development on important estuaries,
increases in predatory falcons, and climate change, including El Nino events
and global warming (natural or human-influenced), causing subtle changes to
habitat, food and breeding success, especially in the Arctic where global
warming is having the greatest impact.
> The report by the CWS shorebird committee, of copy of which was released
to The Vancouver Sun, describes the population declines as "widespread and
pervasive" and calls for both expanded research and the "urgent need for
conservation measures."
> Shorebirds are especially vulnerable to disturbances because of their long
migrations, their competition with humans for shoreline habitat and their
concentration in large numbers at key feeding sites.
> On the Pacific Coast of North America, the main sites include San
Francisco Bay, Grays Harbor, Wash., the Fraser River delta, the Stikine
River delta and Copper River in Alaska.
> Researchers say the findings should spur greater efforts to preserve
shorebird habitat all along the flyway, including the Fraser delta, used by
more than 1.5 million shorebirds annually, mostly western sandpipers on
their annual migration.
> Although shorebirds have survived millions of years and numerous climate
changes, including ice ages, it's possible they might not cope with climate
change sped up by the greenhouse effect, the result of widespread burning of
fossil fuels.
> "We have to look everywhere, over the entire range," said Rick McKelvey,
CWS manager in B.C. "The worst case is that climate change is happening so
fast, because of something we've done, that they can't adapt."
> Also of concern is that many shorebird species have low genetic variance,
suggesting they went through a "bottleneck" in the past during which
populations were rebuilt by relatively few breeders. That means they might
be more vulnerable to rapid climate change.
> Consistent with trends elsewhere on the continent, surveys last year at
Sidney Island near Victoria showed juvenile western sandpipers had dropped
to about 50 per observer day from about 250 in 1992.
> "This is significant for the young ones," Butler said. "The adult ones
probably won't be far off."
> Researchers also counted about one million western sandpipers at Roberts
Bank at the single-day peak of their migration in 1992, compared with fewer
than 200,000 last year.
> Because of the need for improving the way large flocks are counted,
however, researchers are less confident in the Roberts Bank numbers. They
also feel that increased numbers of falcons might be affecting shorebirds or
causing them to find alternative feeding spots where they would not be
counted.
> The Fraser delta has about 25,000 hectares of mudflat and sandflat
habitat, compared with about 100 hectares at Sidney Island.
> The province has declared Boundary Bay and Sturgeon Bank wildlife
management areas, but has delayed a similar designation for Roberts Bank,
the subject of native land claims negotiations.
> Shorebirds in the Lower Mainland face a variety of potential threats. The
province still allows waterfowl hunting despite the wildlife management
designations; residential and port development encroaches on shorebird
habitat; agricultural lands important to birds are eroded by industrial
greenhouses; municipal and regional authorities permit dogs to roam
off-leash in bird habitat, and ship traffic continues to pose an oil-spill
risk.
> SHOREBIRDS IN THE LOWER MAINLAND
> Some examples in the trend in populations of North American shorebirds
found in the Lower Mainland:
> SANDERLING
> Numbers in decline across North America particularly along East Coast.
> Rarely seen in Lower Mainland. Most commonly seen during fall migration.
Frequents the sandy flats of Boundary Bay. In winter largest numbers are
found around Iona and Sea Islands.
> WESTERN SANDPIPER
> One of the most common shorebirds in the Vancouver area, but evidence
suggests numbers are decreasing on the Pacific coast. Total numbers passing
through in autumn migration thought to exceed one million. Commonly seen
along Boundary Bay and Iona Island sewage ponds.
> KILLDEER
> Small flocks of Killdeer often seen in agricultural fields and the shores
of rivers and sloughs. In winter, largest numbers are seen on Westham
Island. Killdeers breed throughout the Fraser River delta.
> SEMIPALMATED PLOVER
> Believed to be in decline on Pacific coast flyway. Migrates chiefly
inland, but can be seen each year in small numbers in Boundary Bay and off
Sea Island particularly during autumn.
>
>
> The article you just read is from The Vancouver Sun newspaper in Vancouver
BC. Looking for a job in Vancouver? Try our Careerclick site at
http://www.careerclick.com/bc. Canucks fan? Follow the team at
http://www.thecanucks.com.
>