Research Finds Grassland Birds Declining, Says Interior Department

Nigel Allen ae446 at Freenet.carleton.ca
Fri Jul 2 03:24:50 EST 1993


Here is a press release from the U.S. Department of the Interior.
I downloaded the press release from the PR On-Line BBS in 
Maryland at 410-363-0834.

 Research Finds Grassland Birds Declining, Says Interior Department
 To: National Desk, Environment Writer
 Contact: Megan Durham of the Department of the Interior,
          202-208-4131

   WASHINGTON, June 24  -- Native birds in North
America's grasslands have suffered steeper, more consistent,
and more widespread declines over the past 25 years than any
other U.S. bird group, according to research by the Interior
Department's U.S. Fish and Wildlife Service.
   According to data from the Service's annual Breeding Bird
Survey, seven of the 12 bird species considered endemic to the
Great Plains grasslands declined during the past 26 years, with
declines of four (mountain plover, Franklin's gull, Cassin's
sparrow, and lark bunting) being statistically significant.  The
mountain plover has been identified as a candidate for listing
under the Endangered Species Act.
   In addition, 16 of 25 more widespread birds that are
considered "secondarily" evolved to grasslands also declined,
with six showing significant declines (eastern meadowlark and
grasshopper, Henslow's lark, Brewer's and clay-colored
sparrows) considered statistically significant.  Across all
rassland species, only upland sandpiper and McCown's longspur
have increased significantly since 1966.
   "These birds are part of America's history," said Secretary of
the Interior Bruce Babbitt.  "They evolved with the bison, they
were known to the Native Americans, and their songs were heard by
the pioneers when the wagon trains rolled across the prairies.
   "The discovery that the grassland birds are declining shows
the importance of surveying our biological resources, and the
need to consider entire ecosystems in our wildlife conservation
programs," Babbitt said.
   The findings are outlined in a paper by Fritz L. Knopf of the
Service's National Ecology Research Center in Ft. Collins, Colo.,
to be published in a fall issue of the journal, "Studies in Avian
Biology."
   The grassland birds spend the summer in North America.  Many
remain in the United States, wintering in grassland of Oklahoma,
Texas, Arizona, and California's Central Valley.  Others -- like
many forest birds -- are considered "neotropical migrants"
because their winter ranges extend into Mexico, Central, and
South America.  Unlike the forest birds, these species winter in
Latin American grasslands which are experiencing similar problems
to those occurring in North America.
   The reasons for the population declines among grassland birds
are not fully understood, but are believed to be caused by
changes in the grassland ecosystems of the Great Plains over the
past 100 years, according to Knopf.
   The Great Plains extend from south central Saskatchewan to
central Texas.  The grasslands include shortgrass prairie in the
west, and tallgrass prairie in the east.
   Only five percent of all North American bird species are
thought to have evolved within the Great Plains.  The native
birds evolved with specific ecological niches within the
grasslands.  Species like Baird's sparrow and McCown's and
chestnut-colored longspurs evolved with grazing mammals like
bison, while species like the ferruginous hawk, prairie falcon,
and burrowing owl are associated with prairie dog towns.  Some
species depended upon periodic rejuvenation of their habitat by
wildfires that swept the prairies.
   Over the past 100 years, the Great Plains have changed
enormously.  Systematic slaughter reduced the plains bison from a
population of 30 million or more to about 300 by 1889.  The other
major grazer -- the prairie dog -- also was exterminated on a
wide scale.  The prairie dog ecosystem of the Great Plains has
been reduced from an estimated 700 million acres in the late
1800s to about 2 million acres today.
   Plowing also changed the plains landscape.  In North Dakota,
for example, less than 25 percent of the native prairie remains.
In Iowa, where 30 million acres of tallgrass prairie are
estimated to have existed at the beginning of the 19th century,
only a small fraction remains in isolated tracts scattered
throughout the state.  Fire control and water management
practices also altered the grasslands by making conditions
favorable for the growth of shrubs and small trees.
   According to Secretary Babbitt, new ecosystem conservation
efforts can help North America's native grassland birds.  The
Great Plains Initiative is a program spearheaded by the Western
Governors Association and involving State, Federal and
Provincial governments of the U.S. and Canada.  Aimed at
conserving the Great Plains ecosystem and preventing more species
from becoming endangered, the initiative offers promise for
native grassland birds.
   Projects underway to enhance waterfowl and other bird habitat
under the North American Waterfowl Management Plan have already
helped wetland-associated birds like the marbled godwit and
Wilson's phalarope.  Under the plan, state, federal, and private
organizations in the U.S., Canada, and Mexico are working
together in joint ventures to restore wildlife habitats.
   And because grassland birds evolved along with grazing
mammals, researchers believe grazing of domestic animals can be
compatible with and even help populations of some native
grassland birds.
   "The important thing is that we have identified the problem and
we have already begun tackling it on an ecosystem-wide basis
through cooperative partnerships," Babbitt said.  "Conservation
came too late to save the passenger pigeon or the great bison
herds -- but there's still time to save the birds of the American
prairies."

 -30-

-- 
Nigel Allen, Toronto, Ontario, Canada  ae446 at freenet.carleton.ca



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