As population declines threaten avian species throughout California, standardized monitoring strategies are increasingly important for habitat management and conservation. Passive acoustic monitoring reduces the need for human observers, creating the opportunity to monitor species with limited funding or staff. Using a novel approach, we deployed autonomous recording units (ARUs) across nine public wildlife areas and refuges in northern California to assess occupancy and relative abundance of vocalizing avian species during spring and summer of 2024. ARUs were deployed using a random sampling design within a hexagonal tessellation grid. Recordings from 284 ARU stations were processed using BirdNET Analyzer, from which a subsample of vocalization detections were validated and detection probability thresholds developed. Maps of relative abundance were created using Kriging interpolation, and occupancy was estimated using single-site single-season models. While previous large-scale ARU studies have provided valuable data, making inference at local scales creates a powerful tool to inform and improve habitat management practices. Further, this passive monitoring technique can be applied to any vocalizing species that is detected by BirdNET, including anuran and mammalian species. The broad applicability of this work emphasizes the significance of integrating and standardizing acoustic monitoring in an increasingly fragmented landscape.

The Bay Point Restoration and Public Access Project was initiated with goals of restoring ecological habitat, providing public access and long-term climate resiliency at a former sand dredge processing site in the waterfront community of Bay Point along the southern shoreline of Suisun Bay, in northern Contra Costa County, California. The project hydrologically reconnected the site to adjacent tidal emergent marsh and restored transitional and upland habitat. Public access improvements included a 1-mile loop trail, kayak launch, parking, restroom, and other visitor amenities. Providing public access was a primary project focus because the Bay Point community represents one of the most underserved areas in the region, with residents experiencing social and financial hardships with scarce access to outdoor recreation and interpretive opportunities. A key finding of the project is that restored habitat in close proximity to public access can be compatible land uses as evidenced by California black rail (Laterallus jamaicensis coturniculus) occupying the restored area shortly after construction. The California Back Rail is listed as a California threatened species. Bay Point Regional Shoreline provides habitat for several special status species including the salt marsh harvest mouse, white-tailed kite, northern harrier, salt marsh common yellowthroat, and Suisun song sparrow. Analysis of systematically obtained call count data, collected during the breeding seasons of 2020 to the present is showing a positive trend of increasing California black rail occupancy in the restoration area. Field research is showing that the California black rail population is now three times higher in this recently restored wetland, which may aid recovery efforts elsewhere designed to enhance breeding habitat for this threatened species and provide public access.

Greater Sage-Grouse (Centrocercus urophasianus; sage-grouse) populations have declined significantly across their range and in the Bi-State Distinct Population Segment (DPS), largely attributed to habitat loss and fragmentation. Over the last few decades, wildlife managers have implemented habitat conservation actions aimed at restoring sage-grouse populations in the Bi-State DPS. Using a Progressive Change Before-After-Control-Impact Paired Series design, we evaluated the effects of conservation actions on sage-grouse population abundance using count data from 57 leks for which we had lek data prior to and after conservation implementation during 1990–2021. Relative to leks with no conservation actions, leks within 5 km of a conservation action had an average annual increase in abundance of 4.4% since 2012, resulting in a total increased abundance of 37.4%. While Bi-State sage-grouse populations declined overall through our study, the total sage-grouse abundance in the Bi-State DPS today is 37.4% higher than if no conservation actions had occurred. Additionally, we estimated sage-grouse population trends across six population cycles from 1960–2023. Estimated population growth of the Bi-State DPS across the last two (15 years), four (28 years), and six (45 years) population cycles was 0.976 (95% CRI = 0.964 – 0.986), 0.990 (0.977 – 0.999), and 0.979 (0.969 – 0.987), respectively.

Tropical forest restoration holds significant potential for mitigating biodiversity loss, particularly in regions with high levels of endemism, such as Hawaiʻi. This study assesses the impact of restoration efforts on avian populations across two restoration sites: Hakalau Forest National Wildlife Refuge and Puʻuwaʻawaʻa Forest Bird Sanctuary. By analyzing changes in canopy cover and bird abundance over a ten-year period using both point count surveys and remote sensing techniques, we examine the correlations between restoration success and the recovery of native bird species such as the ‘i’iwi (Drepanis coccinea) and ‘apapane (Himatione sanguinea). Preliminary results suggest a positive correlation between increased native tree cover and higher relative abundance of native birds in restored areas compared to adjacent non-restored regions. However, the response of avian communities varies by species and site, influenced by factors such as forest maturity, proximity to intact habitats, and ongoing threats from invasive species and disease. This study highlights the importance of continuous monitoring and adaptive management to optimize restoration outcomes and support the recovery of Hawaiʻi’s native avifauna.

The Central Valley has been dramatically transformed over the last century by human activities, resulting in once abundant bird populations reduced to relatively small populations or locally extinct. In order to inform restoration design and support conservation of Central Valley grassland and riparian birds, we evaluated the success of restoration sites in meeting Central Valley Joint Venture objectives for species' breeding densities. We visited 11 restoration sites in the Sacramento Valley that had both riparian and grassland vegetation, ranging in ages from 5 to 21 years old. Point count surveys were conducted twice in May-June 2023 at 42 riparian and 38 grassland locations. To evaluate the current contribution of each restoration site to meeting CVJV objectives, for each site and habitat type, we compared the mean density estimates ± SE for each species against the short-term (10-year) objectives. We found considerable variation among species, sites, and habitat types in terms of meeting short-term density objectives for focal species. While these evaluations can effectively support bird conservation, improved recommendations for restoration design will arise through increased survey effort and additional survey methods, additional sites across successional stages, evaluation of habitat covariates, indicator scores for biodiversity and consideration of multiple benefits or outcomes simultaneously.

The establishment of a long-term statewide climate and biodiversity monitoring network is crucial to the successful implementation of Governor Newsom's Nature-Based Solutions Executive Order N-82-20 which is commonly referred to as the 30x30 initiative. As a result of this executive order, the California Department of Fish and Wildlife (CDFW) is working with several partners to establish a Climate-Biodiversity Sentinel Site Network to monitor ecosystems and wildlife throughout California. CDFW has established 39 sentinel sites on select Wildlife Areas and Ecological Reserves across the state. The network will conduct annual biodiversity inventories, real-time climate monitoring, and migratory species tracking via Motus. Resulting data is processed using automated and machine learning tools. The intention of the data is two-fold with (1) to be a resource for land managers to make informed management decisions in light of climate change and its impact on biodiversity and (2) to be a transparent and inclusive open-source data set for public use. This presentation will discuss the results of data collected during the 2023 field season, some preliminary results of the 2024 field season, and future directions for the network.  

Jim Stilley AND Nicole Cornelius will present this paper.