The greater sage-grouse (Centrocercus urophasianus) is a species of concern in areas of sagebrush habitat in the western United States and a Bureau of Land Management (BLM) sensitive species in the state of Utah. The Greater Sage-grouse Conservation Objectives Final Report (COT report) (USFWS 2013) states that "Functional habitat loss also contributes to habitat fragmentation, as greater sage-grouse avoid areas due to human activities, including noise, even though sagebrush remains intact". The COT report discussion for several of the threats to sage-grouse populations in the Vernal and Price Field Offices (VFO and PFO) includes recommendations to avoid or buffer impacts due to noise from energy, mining, recreation, and urbanization. The Utah Greater Sage-Grouse Approved Resource Management Plan Amendment (ARMPA; BLM 2015) incorporates these concerns by dictating that in Priority Habitat Management Areas (PHMA) noise from discrete anthropogenic disturbances will not exceed 10 decibels above ambient sound levels at occupied leks from 2 hours before to 2 hours after official sunrise and sunset during the breeding season, and that the BLM will support the establishment of ambient noise levels for PHMA habitat area leks (MA-SSS-3E). These leks are also encompassed within the Carbon and Uintah State Designated Sage Grouse Management Areas (SGMAs). Currently ambient noise data is lacking for all of the leks within the VFO and PFO. The objective of the contract is to measure ambient noise levels at approximately 65 leks in the VFO and PFO during the 2021-2023 breeding seasons, and to characterize existing anthropogenic sources of noise at these lek sites. This information would enable the assessment of proposed project disturbance impacts at lek sites, allowing the development of reasonable impact avoidance and mitigation measures where necessary. In addition, the data would provide input for the HAF site scale lek assessments and could be used to identify areas where noise disturbances are degrading habitat that is otherwise suitable for grouse. This in turn could result in actions to mitigate noise impacts at leks, potentially increasing effective sage-grouse habitat.

The scope of the contract is the measurement of ambient noise levels at approximately 65 leks in the VFO and PFO over 3 years (2021-2023) breeding season, and to analyze and report the results of the monitoring, and to characterize existing anthropogenic sources of noise at lek sites. This information would enable the assessment of proposed project disturbance impacts at lek sites, allowing the development of reasonable impact avoidance and mitigation measures where necessary. In addition, the data would provide input for the HAF site scale lek assessments and could be used to identify areas where noise disturbances are degrading habitat that is otherwise suitable for grouse. This in turn could result in actions to mitigate noise impacts at leks, potentially increasing effective sage-grouse habitat.

Currently ambient noise data is lacking for all of the leks within the VFO and PFO. If this monitoring data is not obtained valid assessments of proposed project disturbance impacts at leks site cannot occur thus increasing the chances for functional habitat loss which can contributes to habitat fragmentation, as greater sage-grouse avoid areas due to human activities, including noise, even though sagebrush remains intact.

The Utah Greater Sage-Grouse Approved Resource Management Plan Amendment (ARMPA; BLM 2015) incorporates these concerns by dictating that in Priority Habitat Management Areas (PHMA) noise from discrete anthropogenic disturbances will not exceed 10 decibels above ambient sound levels at occupied leks from 2 hours before to 2 hours after official sunrise and sunset during the breeding season, and that the BLM will support the establishment of ambient noise levels for PHMA habitat area leks (MA-SSS-3E). Utah Greater Sage-Grouse Plan (2019): Conservation Strategies: 1h. Continue to fund, support and implement critical research that supports the implementation of this Plan and future improvements to this Plan. The Greater Sage-grouse Conservation Objectives Final Report (COT report) (USFWS 2013) states that "Functional habitat loss also contributes to habitat fragmentation, as greater sage-grouse avoid areas due to human activities, including noise, even though sagebrush remains intact". The COT report discussion for several of the threats to sage-grouse populations in the Vernal Field Office (VFO) includes recommendations to avoid or buffer impacts due to noise from energy, mining, recreation, and urbanization.

Not Applicable.

Not Applicable.

No NEPA or archeological clearances are required for this type of monitoring. Written landowner permission will be obtained from private landowners before any monitoring is conducted on their lands.

The measurement period shall be at least 7 days at each lek during suitable climatic conditions (e.g., not during a thunderstorm or noisy natural event). Environmental conditions shall be measured throughout noise measurement periods so that measurements made during unsuitable conditions (e.g., loud weather events) can be excluded. For measurement of ambient noise levels, measurements shall only be made under calm conditions (i.e., <2.2 mph at 0.3 m above ground). Temperature, humidity, ground moisture and snow cover can influence the propagation of noise and shall also be recorded. Measurements made while sage-grouse are present on the lek shall be excluded from ambient or noise level calculations as sage-grouse vocalizations are likely to be louder than all but the loudest and closest anthropogenic noise sources. Microphones shall be placed 0.3 m above ground, approximate ear height of greater sage-grouse, at the edge of the lek in sagebrush habitat (and thus not visible to displaying grouse). Critical metrics shall be collected: L50, L90, L10, Leq, Lmin, and Lmax. All measurements shall be collected in A-weighted decibels (dBA) and computed for each hour of the measurement period at each site. Site summary metrics shall be prepared for three daily time periods: 0000-2400, 0800-1800, and 1800-0800. Accurate location data shall be collected for each measurement location. Surveyors also shall catalog the type and location of all nearby sources of anthropogenic noise. For all noise and ambient measurements, surveyors shall catalog the type and location of all nearby sources of anthropogenic noise. The final report, due by September 30 of each year, shall include sound level metrics listed above for three daily time periods for each lek monitored.

The scope of the contract is the measurement of ambient noise levels at approximately 65 leks in the VFO and PFO over 3 years (2021-2023) breeding season, and to analyze and report the results of the monitoring, and to characterize existing anthropogenic sources of noise at lek sites.

Vernal and Price BLM Field Offices Southeast Region UDWR Private Landowners

This information would enable the assessment of proposed project disturbance impacts at lek sites, allowing the development of reasonable impact avoidance and mitigation measures where necessary. In addition, the data would provide input for the HAF site scale lek assessments and could be used to identify areas where noise disturbances are degrading habitat that is otherwise suitable for grouse. This in turn could result in actions to mitigate noise impacts at leks, potentially increasing effective sage-grouse habitat.

The Greater Sage-grouse Conservation Objectives Final Report (COT report) (USFWS 2013) states that "Functional habitat loss also contributes to habitat fragmentation, as greater sage-grouse avoid areas due to human activities, including noise, even though sagebrush remains intact". This information would enable the assessment of proposed project disturbance impacts at lek sites, allowing the development of reasonable impact avoidance and mitigation measures where necessary. In addition, the data would provide input for the HAF site scale lek assessments and could be used to identify areas where noise disturbances are degrading habitat that is otherwise suitable for grouse. This in turn could result in actions to mitigate noise impacts at leks, potentially increasing effective sage-grouse habitat.

04/01/2021

04/21/2025

2025

The primary objective of this study was to measure sound levels at 65 leks in east-central Utah over a three-year period. Of these 65 leks, the contractor was unable to obtain landowner permission to access 11 leks, resulting in measurements at 54 leks. A total of 12,644 hours of acoustic data at 54 leks in northeast Utah in April--May of 2021--2024 was obtained. The average number of hours at each lek was 234 (9.8 days), with a range of 53-320 hours. Sound level decibel data alone do not allow identification of all sources of sounds. When conducting acoustic studies, it is essential that the source of common sounds, both natural and non-natural, be identified. Further, it is helpful to determine the percent time that such sounds are audible. This was accomplished by collecting digital recordings during the entire measurement period, and then listening to a sample of digital recordings and identifying sound sources via office logging. Listening and logging is labor intensive, thus logging was only conducted for a sub-sample of the measurement period. The contractor listened to two days from each site, one weekday and one weekend day, and used a sample scheme of a 10-second recording every 4 minutes. A 4-minute sample scheme has been shown to collect common anthropogenic events, such as aircraft and traffic (Ambrose, unpublished data). A 10-second recording every 4 minutes resulted in a 1-hour recording for each day sampled. All sound sources were logged into a spreadsheet and audibility metrics computed from those spreadsheets. Common natural sound sources identified in this segment were wind, bird, coyote, aircraft, vehicle, and domestic animals. A final report is included in the project documents.

Greater Sage-Grouse (Centrocercus urophasianus) use elaborate audio and visual display behaviors to attract and select mates and depend on audio communication between females and chicks during brood rearing. Anthropogenic sounds are a potential threat to Greater Sage-Grouse, and sound levels prior to development activities are essential to understanding and predicting potential impacts. The Utah Greater Sage-Grouse Approved Resource Management Plan states that in Priority Habitat Management Areas noise from discrete anthropogenic disturbances will not exceed 10 decibels (dB) above background sound levels at occupied leks from 2 hours before to 2 hours after official sunrise and sunset during the breeding season. Ambient noise data was not available for all leks within the BLM Vernal and Price Field Offices in the Green River District. The objective of the study was to measure ambient noise levels at 65 leks in the VFO and PFO during the 2021-2023 breeding seasons, and to characterize existing anthropogenic sources of noise at these lek sites. Heavy snowpack in spring of 2023 made access to the majority of leks in the Vernal Field Office impossible. Therefore, the affected leks were surveyed during the 2024 breeding season. Of the 65 leks, the contractor was unable to obtain landowner permission to access 11 leks, resulting in measurements at 54 leks.

Information gained in this study will enable the assessment of proposed project disturbance impacts at lek sites, allowing the development of reasonable impact avoidance and mitigation measures where necessary. In addition, these data provide input for the HAF site scale lek assessments and could be used to identify areas where noise disturbances are degrading habitat that is otherwise suitable for grouse. This in turn could result in actions to mitigate noise impacts at leks, potentially increasing effective sage-grouse habitat.