The San Clemente Island loggerhead shrike (Lanius ludovicianus mearnsi) is one of the most endangered avian sub-species in North America. The effective population size peaked in the late 2000s, but in recent years has ranged between 32 and 137 individuals. Nest failure associated with predation events has been considered a major factor inhibiting recovery. The US Navy leads recovery efforts, which includes releasing captive-bred individuals, non-native predator control, and extensive monitoring. To better support this mission, understanding potential impacts of other factors that may be limiting population recovery, such as climate change, changes in breeding habitat composition, fire impacts, and prey availability, are critical in managing this subspecies. Additional investigations are underway to address data gaps as part of an overall recovery management plan. These efforts include conducting a population viability analysis, assessing habitat factors associated with successful nesting, and investigating over-winter survival. We are also investigating the feasibility of evaluating the effects of invasive plant densities on prey abundance and/or availability. In this talk we will discuss our approaches to filling these data gaps, and initial results from some of the tasks already underway.

Vandenberg Space Force Base encompasses 42 miles of undeveloped coastline which provides ecologically important habitat for marine mammals. Three common pinnipeds, harbor seals (Phoca vitulina), elephant seals (Mirounga angustirostris), and California sea lions (Zalophus californianus) occur annually with varying seasonal attendance at 30 haul-out sites within or surrounding base. Numerous monitoring and minimization measures are required by the National Marine Fisheries Service when rocket launches are predicted to cause Level B (behavioral) harassment. This presentation will provide an overview of 20+ years of launch monitoring (e.g. sonic boom modeling and acoustic disturbance to pinniped haul-outs) and dive into species-specific behavioral observations from two recent launch case reports on mainland California and the North Channel Islands. To summarize, launch-specific monitoring results indicate that 45-100% of harbor seals and sea lions alert and/or flush due to booster roar or sonic booms, however, in almost all instances, peak abundance counts return to baseline within 12 hours. In contrast, elephant seal disturbance appears to be minimal. Finally, we discuss future efforts in alignment with our most recent NMFS Letter of Authorization to contribute to our understanding of population-level shifts in state-wide abundance patterns for these top marine predators.

Understanding how species of concern respond to anthropogenic activities is becoming increasingly important. While the ways in which anthropogenic activities affect species are potentially many, our understanding the effects of anthropogenic noise on species is still developing. Vandenberg Space Force Base (VSFB), situated along the Central Coast of California, presents an opportunity to study the effects of anthropogenic noise on species of concern as 1) the rate of rocket launches/landings has recently increased and is predicted to significantly increase in the coming years compared to the last three decades and 2) there are multiple threatened and endangered species at VSFB that may be affected by the increased launch cadence. Our interdisciplinary research team consisting of wildlife ecologists and physical acousticians is working to understand 1) the acoustical landscape at VSFB before and after rocket launches and 2) the short and long-term responses of threatened and endangered species inhabiting areas relatively close to active VSFB launch complexes. Using previously collected and current species’ data and acoustic data from VSFB, we will create models that describe and help predict species responses to rocket launches. We will discuss the scope and overview of this project.

Harsh environmental conditions have the potential to damage important parts of an acoustic recording system. Some companies such as Wildlife Acoustics specialize in building outdoor acoustic recording systems with functionalities and ruggedizations catered to environmental projects. One of their products is the Song Meter 4 (SM4). A team from Brigham Young University and California State University Bakersfield deployed 31 SM4 recorders from 12/2/23 to 9/7/24 in a costal environment located on Vandenberg Space Force Base in southern California. After bringing in the recorders to be serviced all of them were visually in poor condition and we felt the need to check the acoustic fidelity of the microphones to see if the ruggedization of the SM4s was enough to hold up to long term deployment on the coast. To do this a high-fidelity microphone is used as a baseline standard and each microphone on each recorder is systematically compared to this baseline. Measurements are taken in an anechoic chamber to ensure minimal interference from contaminating noise. The difference between the baseline microphone and the microphones that were deployed are compared to the difference between the baseline microphone and four SM4 units that were not deployed. Results will be discussed.