Sage Grouse at Risk
Dwindling Populations Jeopardized by Habitat Destruction
"Looking up from the tent at the edge of the
bluff above us, we could see projecting over it the heads of hundreds of
the birds, and, as those standing there took flight, others stepped forward
to occupy their places. The number of Grouse which flew over the
camp reminded me of the old-time flights of Passenger Pigeons that I used
to see when I was a boy. Before long, the narrow valley where the
water was, was a moving mass of gray. I have no means whatever of
estimating the number of birds which I saw, but there must have been thousands
of them."
—Dr. George Bird Grinnell, Wyoming, October
1886
The "moving mass" of grouse that Dr. Grinnell saw 113 years ago were
sage grouse. While none of us expects to see sage grouse in such great
numbers today, few of us want the birds to face the same fate as the passenger
pigeon. Unfortunately, that may be the case.
Sage grouse numbers and range began their decline shortly after Dr.
Grinnell watched thousands of them fly over his Wyoming camp. Once found
in 16 states and three Canadian provinces, they are now gone from five
states (Arizona, Kansas, Nebraska, New Mexico and Oklahoma) and British
Columbia and almost gone in Alberta and Saskatchewan. Sage grouse are declining
in Nevada, barely hanging on in four states (North and South Dakota, Washington
and California) and marginal in Colorado and Utah. In Idaho, sage grouse
numbers are at record lows. The largest remaining sage grouse populations
are found in Montana, Oregon and Wyoming.
Biologists conservatively estimate that at least half of the original
area occupied by sage grouse can no longer support the birds. While this
decline has been a long-term trend, it has accelerated since the 1980s.
Renowned sage grouse expert Clait Braun estimates that grouse populations
have decreased at least 30 percent since 1985. Although we still have more
than 20,000 grouse in Wyoming, our numbers are declining as well. Today,
there are no stable — let alone increasing — populations of sage grouse
anywhere in their range.
Dwindling Habitat
What’s wrong? Why are we losing the sage grouse? The culprit is habitat
destruction. As its name implies, the grouse’s habitat is sagebrush. Sage
grouse can only exist in the expansive sagebrush landscapes of the western
United States and Canada. This large, flamboyant bird is perfectly adapted
to eating sage, living in sage, raising chicks in the shadow of sagebrushes
and surviving the winters in the exposed sagebrush steppes.
As with so many of our declining wildlife species, dwindling sage grouse
populations warn us that the entire sagebrush ecosystem, and all the species
that depend on it, is in trouble. Sage grouse are suffering from an inter-related
and overlapping triple threat: habitat loss, habitat fragmentation and
habitat degradation.
Habitat is lost from plowing, irrigating and planting crops, mining
and oil and gas development, residential development, roads, highways and
reservoirs. Habitat is fragmented by the destruction of sagebrush (through
herbicides, burning or clearing), fences (particularly those made of woven
wire) and power lines and fence posts that provide perches for raptors,
which prey on grouse, prompting them to abandon these areas. Habitat is
degraded by repeated livestock grazing, herbicide use, fire and invasions
of exotic plant species, especially introduced annual grasses. While predators
are often blamed for declining sage grouse populations, they do not make
a difference until habitat loss has already reduced bird numbers and weakened
those that remain, making them more vulnerable to predation.
Surviving on Sagebrush
What can we do to protect the sage grouse? Clearly, we must protect the
sagebrush ecosystem that the birds depend on for their survival. Sage grouse
need vast expanses of sagebrush with a healthy understory of native grasses
and forbs (leafy plants). Chicks need protein-rich insects for their first
few weeks of life, and then they need a combination of insects and forbs.
Adults eat grasses, insects and forbs, and in the winter they survive on
sagebrush alone.
Females need nest sites that are hidden from predators, usually tucked
under sagebrush. The sagebrush needs to be big enough to hide under but
not so big that it crowds out the understory of grasses and forbs.
To breed, the grouse gather at "leks," open spaces in the sage where
males perform spectacular breeding displays for prospective mates. While
much of sage grouse conservation has focused on these leks and the circles
around them that supposedly harbor nesting grounds, biologists are finding
that conservation strategies need to be more flexible, based more on actual
studies of where the best nesting, feeding and loafing habitat is found.
Development Threats
The biggest threat to the grouse may be from the continually expanding
natural gas and mineral development in our basins. For example, sage grouse
habitat in the Green River Basin’s Jonah II gas field is the most productive
in the state. Yet, according to the Wyoming Game and Fish Department, total
male sage grouse attendance at leks in the Pinedale/Jackson area has declined
by approximately 50% and "the average number of males per lek… has decreased
from 61 males in 1958 to 15 males per lek in 1996."
The continued development, expansion and infilling of gas fields, with
their well sites and roads, fragments and destroys sage grouse habitat.
Well structures provide perches for preying raptors and the constant human
activity disrupts the bird’s behavior.
BLM Action Needed
In Wyoming, with our vast sagebrush landscapes, we may still have the opportunity
to protect and improve sage grouse habitat. Because the Bureau of Land
Management manages the bulk of sagebrush habitat in Wyoming, the future
survival of sage grouse may well lie in the agency’s hands. If the tide
does not turn soon, it is inevitable that the sage grouse will be a candidate
for listing under the Endangered Species Act.
The BLM should take a hard look at how its overall management practices
affect the grouse, and determine how human activities can be conducted
in a manner that protects sage grouse and safeguards their future. Some
grazing practices may need to be modified to conserve grasses and forbs
when the grouse need them most. Prescribed burns, herbicides and other
sagebrush-control methods should be closely scrutinized for their impacts
on grouse.
For those of you who have never braved a late winter dawn to watch (from
a suitable distance so you don’t disturb the birds!) sage grouse strutting
as the sun rises—do it soon. Much like Dr. Grinnell’s tale of endless numbers
of sage grouse filling the skies, your story about this experience may
be one you tell your grandchildren about how the West used to be. |