AN INTENSIVE CAPTURE-MARK-RECAPTURE STUDY OF A POPULATION OF CASCADES FROGS ON MANAGED PRIVATE TIMBERLANDS IN THE SOUTHERN CASCADES

Bennie Johnson Howell; Collins Pine Company; bjohnson@collinsco.com; Matt Reno

Cascades frogs occur in Northern California and are a candidate species under the California Endangered Species Act due to declining populations from a variety of threats. Historically the Klamath Mountains have held large populations of Cascades frogs. However, in the Southern Cascades range, few extant populations exist and population numbers are generally low. We monitored one of the remaining robust populations in the Southern Cascades, which occurs at the southern extreme and lower elevational limits of its range. We intensively monitored the population using capture-mark-recapture techniques for 4 consecutive years. From 2018-2021, the population experienced variable climatic conditions, including a historically wet winter in 2018-2019 and record-setting drought in 2021. During this time, we have been able to assess habitat occupancy, population structure, and seasonal movements. This intensive data collection has allowed us to develop conservation actions to help maintain the population, and further adds to the overall knowledge of the species.

Endangered Species Recovery Strategies  InPerson Presentation

 

RESPONSE OF NESTING WESTERN SNOWY PLOVERS TO COASTAL DUNE CONTOURING AT VANDENBERG SPACE FORCE BASE

Jamie K. Miller; Point Blue Conservation Science; jmiller@pointblue.org; Angela Fortuna, Lynne Hargett, Julie Howar, Emily Rice, Dan Robinette

Invasive plants negatively impact coastal dune ecosystems worldwide, stabilizing dune habitat and reducing early successional stage beach dynamics. Dune restoration may require mechanical contouring with bulldozers to remove vegetation and extensive root systems. We assessed the effectiveness of a coastal dune contouring project at Vandenberg Space Force Base in central California by monitoring the nesting response of western snowy plovers (Charadrius nivosus nivosus), which rely on early successional habitat. Two beach sections were mechanically contoured in 2014 and 2015, opening 30.5 ha of previously marginal nesting habitat. We investigated changes in beach structure, plover nest density, hatch success, and fledge success from 2011 to 2021 at two contoured sites, two adjacent beachfront sites, and a control site 500 m away. After contouring, the majority of nesting habitat at both contoured sites converted to preferred plover habitat. However, the amount of preferred habitat decreased in subsequent years as vegetation grew back. Nest density increased within both contoured sites immediately after contouring, but decreased in subsequent years. Though variable, hatch success improved at only one contoured site, and fledge success marginally increased following contouring. Without periodic recontouring, vegetation will continue to fill contoured sites and plover productivity will return to pre-contouring levels.

Endangered Species Recovery Strategies  Zoom Presentation

 

CALIFORNIA BLACK RAIL (LATERALLUS JAMAICENSIS COTURNICULUS) RESPONSE TO MARSH ENHANCEMENT AT POINT PINOLE REGIONAL SHORELINE, CALIFORNIA

David L Riensche; East Bay Regional Park District, ; driensche@ebparks.org;

California Back Rail (Laterallus jamaicensis coturniculus) is the smallest rail in North America and is largely a resident of fresh, brackish and saltwater wetlands. Due to habitat degradation and destruction, this species is listed as a threatened species in California. Protecting and managing its breeding habitat and restoring adjacent suitable marsh sites are strategies to help its population recover. Habitat enhancement efforts by staff and volunteers of the East Bay Regional Park District at Giant Marsh in Richmond, California have been improving conditions for this native species since 2004. Analysis of systematically obtained call count data, collected there during the breeding seasons of 2013 through 2021 is showing a positive trend of increasing California Black Rails, as compared to the first baseline information collected in 1977 at this location. Field research also is showing that the rail population is now four times higher at this site and that they are typically confined to high marsh habitat, at the upper limits of tidal flooding. Analyzing these trends occurring within Giant Marsh at Point Pinole Regional Shoreline is providing important information that will aid recovery efforts designed to preserve and manage breeding habitat for this threatened species.

Endangered Species Recovery Strategies   Presentation

 

CREATING HABITAT: A STATEWIDE EXPERIMENT FOR THE WESTERN MONARCH (DANAUS PLEXIPPUS)

Kim E Armstrong; River Partners; karmstrong@riverpartners.org; Helen Swagerty, Cheryl Schultz, Emily Mullins, Erin Hagen, Angela Laws

The Western Monarch’s population has dropped by over 90% in 3 years, putting it at high risk of extinction within the coming decades (Xerces 2020). Factors driving this extinction include a lack of summer and fall migratory breeding habitat and the lack of knowledge of this population’s needs (Pelton et al 2019). To increase habitat connectivity and fill knowledge gaps, River Partners has implemented a statewide project to enhance over 600 acres of habitat, prioritizing existing restoration sites. The planning process considered experimental factors that could be kept consistent across large geographical ranges and differing ecotypes. Prioritization of site locations was based on the ability to integrate into planned restoration activities, presence of irrigation infrastructure, weed pressure, adjacent land uses, and geographic distribution. Plots were created with experimental factors in mind, while also incorporating known needs of the monarch. Experimental plots will be used to study short term changes in pollinator abundance, long-term patterns of monarch colonization and the longevity of floral resource diversity, focusing on reducing competition between milkweed and other understory species. A plot-based design, with consistent milkweed density, but varying experimental factors, is ideal for assessing the preferences of monarchs and other pollinators utilizing the habitat .

Endangered Species Recovery Strategies  InPerson Presentation

 

BUMBLE BEES OF CALIFORNIA: CHANGING DISTRIBUTIONS AND DIVERSITY

Leif L Richardson; The Xerces Society for Invertebrate Conservation; leif.richardson@xerces.org; Rich Hatfield, Hillary Sardinas, Sarina Jepsen

Bumble bees are important pollinators of both wild and cultivated plants, and worldwide, many species are reported to be in decline. California is a hotspot for bumble bee biodiversity, with more than half of North American species occurring in the state, including several near-endemics. The state also features many of the stressors thought to be driving bumble bee declines, including agricultural intensification, loss of habitat to development, and climate change-related ecological disturbance. California has a rich history of entomological research, including both historical specimen collections and recent community science observations. However, the state has never had a standardized inventory of these functionally important insects. In this talk, we summarize the current state of knowledge of California’s native bumble bees, and discuss how a systematic community science survey effort, the California Bumble Bee Atlas, will address information gaps, ultimately informing conservation action throughout the state. Significantly, the project will clarify the current distributions of several imperiled species, including Bombus crotchii, B. franklini, and B. occidentalis, and will result in a baseline dataset that will assist in ongoing and future efforts to protect California bumble bee populations and the pollination service they provide to agriculture and native plant communities.

Endangered Species Recovery Strategies  InPerson Presentation