BLM Adaptive Management Triggers for Oregon Sage-Grouse

The adaptive management strategy was developed as a part of the BLM’s Greater Sage-Grouse Approved Resource Management Plan Amendment (ARMPA) to guide management responses based on the urgency of a decline in population or habitat. Every year staff from the OR/WA State BLM Office evaluate the status and trends of sage-grouse habitat and populations to determine where they will direct resources such as monitoring, fire response, and habitat improvement. The annual report also identifies which factors are most likely the cause of the declines.

The adaptive management strategy uses the terms soft and hard triggers to indicate when a significant threshold is crossed. The triggers are defined for populations and habitat. When a hard trigger is tripped the responses remain in place until the habitat or population trigger rises above the trigger threshold. Exceptions to the hard trigger response are allowed if thresholds are tripped by wildfire or insect outbreak or if a disturbance cap has not been met.

Population Thresholds

Soft trigger- Annual population drops by 40% or more in a single year OR Annual population drops by 10% or more for three consecutive years OR the 5-year moving average drops below the lower 95% confidence interval value.

2022 Status: Two PACs tripped soft triggers last year, Beatys and Paulina/12-Mile/Misery Flat. Beatys recorded 547 males which continued the downward 5-year average. Paulina/12-Mile/Misery Flat recorded 322 males, just two birds shy of a hard trigger.

Hard trigger- For PACs with adequate population data, the 5-year mean population drops below the lower standard deviation value OR PACs with inadequate population data (Louse Canyon and Trout Creeks), the annual population declines by a total of 60% or more over two consecutive years OR when soft triggers for both population and habitat are met within the same PAC

2022 Status: Six PACs are currently in hard trigger status, Baker, Brothers/N. Wagontire, Picture Rock, Cow Lakes, Dry Valley/Jack Mountain, and Warners.

Habitat Thresholds

Soft trigger- The functional habitat drops below 65% of the potential habitat within a PAC but remains above 30%

2022 Status: Trout Creeks and the Cow Lakes PACS remain below the 65% threshold. These two have been below this threshold since before the 2015 ARMPA due to The historic Vale Rehabilitation Project and multiple wildfires removing sagebrush from large sections of the Cow Lakes PAC. 72% of the Trout Creeks PAC has burned at least once since 1975, with many acres burned multiple times. BLM continues to prioritize these areas for restoration.

-Bully Creek, Burns, Folly Farm-Saddle Butte, Steens, and Tucker Hill are in the 65-70% range, which means they are close to tripping a trigger so timely treatments are a management priority.

Hard trigger- The functional habitat drops below 30 percent of the potential habitat within a PAC or when a PAC drops by 5% or more in one year.

2022 Status: No Oregon PACs tripped a hard habitat trigger this year.

Treatments In 2022 BLM implemented vegetation treatments (juniper removal, seeding, sagebrush planting, and herbicide spraying of invasive annual grasses) on 98,467 acres of BLM-administered lands within these PACs and additional treatments occurred on Private lands.

Causal Factor Analysis

The most common and wide-spread causes for decline include fire, invasive annual grasses, degraded native understory vegetation, and fence collision risk.

Factors with a possibly significant role are human infrastructure (mostly roads and power lines), improper livestock grazing (based on last Land Health Evaluations) and recurring drought.

While the amount of infrastructure within a PAC may not have changed appreciably in the years leading up to the decline, predator populations may have expanded due to subsidies associated with power lines and roads. More details about the specific factors that were associated with this year’s triggers are available on page 8 of the 2023 report.