Greater Sage-grouse Abundance and
Seasonal Landscape Use Patterns on the
The Greater sage-grouse (Centrocercus urophasianus) has
been the subject of research and monitoring efforts on the INL
Site since the mid-1970s (Connelly 1982, Connelly 1988). Since
1995, sage-grouse have been monitored annually on the INL Site
during the spring breeding season by counting the number of
males on leks (i.e., areas where grouse congregate for courtship
display and breeding) along designated routes. Three lek routes
are currently monitored: two by S.M. Stoller Corporation
(Stoller) and one by the Idaho Department of Fish and Game (IDF&G).
Greater sage-grouse have received increasing attention from
state and federal agencies as population levels have declined
(Connelly et al. 2004; Idaho Sage-grouse Advisory Committee
2006). On March 5, 2010, the U.S. Fish and Wildlife Service (USFWS)
reported its finding that listing greater sage-grouse as
threatened or endangered under the Endangered Species Act of
1973 is warranted but precluded by higher priority actions.
Thus, the USFWS currently recognizes the greater sage-grouse as
a “candidate species” and will annually review its status to
determine if changing conditions require that the bird be listed
as threatened or endangered.
The DOE-ID recognized that if greater sage-grouse or
other sagebrush-obligate species were listed under the
Endangered Species Act, potentially, further development and
current activities on the INL Site could be delayed or halted to
assess the potential effects on sage-grouse. Therefore, the Environmental Surveillance, Education and Research (ESER)
Program, operated for DOE-ID by Stoller, began studying conservation actions that DOE-ID may
take to minimize threats to sage-grouse.
We are documenting sage-grouse movements and seasonal habitat
preferences across the Site using radio telemetry data gathered
from greater sage-grouse fitted with radio transmission collars.
These data will be used to parameterize spatially explicit
statistical models that will characterize areas most used by
sage-grouse on the Site. Greater sage-grouse on the Site were
fitted with radio collars during the spring of 2008 and 2009.
These birds have subsequently been tracked throughout the year
on both the ground and in the air until the bird either died or
the battery on the transmitter expired. Intensive monitoring of
collared grouse allows us to locate nests and document nest
success, and it facilitates the collection of habitat data that
will help us better understand greater sage-grouse requirements
for nesting, brood-rearing, and winter survival.
Figure 2. Movements of greater sage-grouse collared either in
spring 2008 or 2009. Lines connecting points show estimated
travel paths of birds.
Track radio-collared sage-grouse from point of capture until
the bird dies or the transmitter expires
telemetry data to develop a spatial model that will characterize
nesting, brood-rearing, and winter habitats
Document nest locations and monitor nest success
Develop statistical models to estimate survivorship and
Accomplishments through 2009
In spring of 2008, 34 sage-grouse (22 females, 12 males)
from 10 leks were fitted with radio collars. In 2009, 18
additional sage-grouse (9 males, 9 females) were collared.
Seasonal movements, nesting, brood-rearing, wintering, and
mortality data have been collected for two seasons, and we are
prepared to analyze these data in preparation for the drafting
of a CCA.
sage-grouse locations have been compiled in a Geographic Information
System (GIS), and analysis of greater sage-grouse habitats has
data was collected in 2008 and 2009 at nest locations, and these data
are currently being compiled into a proper database format.
Fifty-two sage-grouse, including 31 hens, have been
collared during the past two years. In
2008, 20 nests were initiated, six of
which were successful (30%), meaning
that at least one egg hatched. Four of
the 6 broods survived until the end of
September, 2008. In 2009, 24 nests were
initiated, 11 of which were successful
(46% apparent next success). At least
seven of the 11 broods survived until
the end of the season in September,
2009, and the fates of two broods are
unknown as the batteries in their radio
collars expired before the end of the
brood rearing season.
Sage-grouse that breed on the INL Site are seasonally
migratory, and collared birds displayed
two general movement patterns. Many
grouse captured on the northern portion
of the Site migrated north into Birch
Creek during the summer and fall,
although two hens also traveled
northeast near the Montana border
(Figure 2). Some grouse captured on the
southeast portion of the Site also
migrated north into Birch Creek, but the
majority moved south, east, and west.
Although our sample size is small
relative to the number of birds on the
Site, these results suggest that birds
on different regions of the Site may
have different migration patterns which
highlight the importance of following
the movements of sage-grouse captured
from various locations on the Site. We
suggest that additional telemetry
studies of greater sage-grouse be
conducted in the central and western
portions of the Site in order to
determine the seasonal migratory
patterns and critical habitat of greater
sage-grouse in those areas.
Plans for Continuation
During 2010, we will organize all
sage-grouse data collected on the Site
since 2006 and draft a CCA between
DOE-ID and USFWS. In May, 2010, DOE-ID
will solicit feedback from the USFWS on
an annotated outline of a draft CCA. In
July, we will have prepared a first
draft to be reviewed by DOE-ID.