Trends and a Targeted Annual Warning System for Greater Sage-Grouse in the Western United States (ver. 3.0, February 2024)

Greater sage-grouse (Centrocercus urophasianus) are at the center of state and national land use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. These data represent an updated population trend analysis and Targeted Annual Warning System (TAWS) for state and federal land and wildlife managers to use best-available science to help guide current management and conservation plans aimed at benefitting sage-grouse populations range-wide. This analysis relied on previously published population trend modeling methodology from Coates and others (2021, 2022) and includes population lek count data from 1960-2022. Bayesian state-space models estimated 2.9 percent average annual decline in sage-grouse populations across their geographical range, which varied among subpopulations at the largest scale of analysis, termed climate clusters (2.2-4.7). Cumulative declines were 40.9, 65.0, and 79.6 percent range-wide across short (19 years), medium (35 years), and long (55 years) temporal periods, respectively. We also present updated results to the TAWS which models rates of change in abundance from spatially structured populations and identifies when local declines fall out of synchrony with trends at larger spatial scales. The TAWS framework provides signals that alert managers to the categorical significance of observed declines while avoiding signals where declines result from drivers operating at larger spatial scales (e.g., periodic reductions in primary productivity owing to drought).

Definitions:

Watch: Assigned to populations that exhibit evidence of population decline below those of their respective climate cluster (slow signal) over 2 consecutive years.

Warning: Assigned to populations that experienced slow signals in 3 out of 4 consecutive years OR a relatively strong magnitude (fast signal) of evidence for 2 out of 3 years.

Watches may identify the need for intensive monitoring whereas warnings may identify the need for management intervention aimed at stabilizing populations.

References:

Coates, P.S., Prochazka, B.G., O'Donnell, M.S., Aldridge, C.L., Edmunds, D.R., Monroe, A.P., Ricca, M.A., Wann, G.T., Hanser, S.E., Wiechman, L.A., and Chenaille, M.P., 2021, Range-wide greater sage-grouse hierarchical monitoring framework-Implications for defining population boundaries, trend estimation, and a targeted annual warning system: U.S. Geological Survey Open-File Report 2020-1154, 243 p., https://doi.org/10.3133/ofr20201154.

Coates, P.S., Prochazka, B.G., Aldridge, C.L., O'Donnell, M.S., Edmunds, D.R., Monroe, A.P., Hanser, S.E., Wiechman, L.A., and Chenaille, M.P., 2022, Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)-Updated 1960-2021: U.S. Geological Survey Data Report 1165, 16 p., https://doi.org/10.3133/dr1165

These data support the following publications:
Coates, P.S., Prochazka, B.G., Aldridge, C.L., O'Donnell, M.S., Edmunds, D.R., Monroe, A.P., Hanser, S.E., Wiechman, L.A., and Chenaille, M.P., 2022, Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)-Updated 1960-2021: Data Report 1165, 16 p., https://doi.org/10.3133/dr1165.