In urban contexts, restoring riparian ecosystems can have widespread benefits, but these efforts are often limited by needs to mitigate flood risks. To evaluate restoration potential in urban riparian systems, we studied responses of a diverse lizard community, including several species that occur in California, to combined flood control and habitat restoration efforts along two waterways over 15 years in urban Tucson, Arizona. We used a before/after-control/impact design to estimate responses to treatments that included bank stabilization and detention basin construction for flood control combined with passive water harvesting, native vegetation planting and seeding, and targeted creation of microhabitats. Overall impacts were mostly positive or neutral, and negative for just one of six focal species. Most species recovered to pre-treatment abundance within 2-3 years, but recovery dynamics varied among species. In general, widely-moving, faster-maturing terrestrial species recovered quickly and responded most positively to restoration, whereas more arboreal species with longer generation times and smaller home ranges took longer to benefit. Our findings suggest management of urban riparian systems can provide simultaneous benefits to humans and herpetofauna. Future efforts may be improved by fostering more heterogeneous cover and potentially translocating animals into restored but disconnected patches of habitat in urbanized landscapes.

Behavioral plasticity can buffer animals against physiological impacts of climate change, but research is needed to understand the limits and consequences of behavioral responses to warming. Increased night activity by diurnal animals is a potential response to warming thought to require considerable behavioral flexibility. We hypothesized that juvenile Mojave desert tortoises (Gopherus agassizii), diurnal ectotherms that typically rely on burrows to conserve limited energy and water reserves during summer, may respond to rising burrow temperatures by shifting from using burrows at night to overnighting at the surface where cooler temperatures reduce metabolic expenditure. This strategy could be energetically adaptive but may increase predation risk. Using time-lapse cameras at burrows and iButton temperature loggers affixed to juveniles and placed at burrow and surface microhabitats during a summer heatwave, we found that individuals often emerge from burrows on evenings when their temperatures approach the voluntary thermal maximum of well-fed, hydrated laboratory animals. Tortoises remained inactive at the surface before returning to burrows after sunrise. By shifting to surface microhabitats at night, tortoises dramatically reduced nighttime body temperatures and energy expenditure during the heatwave. Future research will examine whether this behavioral adjustment to temperature entails greater predation risk.

Repeatable individual behavioral traits, or personalities, mediate the way that organisms interact with and respond to their environments. Such traits are known to predict survival in the wild, thus, in the context of conservation head-starting programs, it is critical to understand how they may be shaped by maternal effects and rearing regimens. As a first step toward understanding these dynamics, we assayed behavior in Mojave desert tortoise (Gopherus agassizii) mothers and offspring that were involved in a head-starting and translocation program. Tortoises were repeatedly tested to characterize exploratory tendencies and boldness. Radiotelemetry was used to track individual movement, habitat use, and survival in the wild. Both hatchlings and mothers exhibited significant repeatability in the majority of behavioral traits. Some traits were correlated with each other, suggesting the possibility of a behavioral syndrome. Correlations between mothers and offspring were limited, but there were significant differences in behavioral traits across clutches. For mothers, we found significant associations between behavioral traits and time spent in burrows in the field. Field data for juveniles are still being collected and analyzed. Our results will be discussed in the context of desert tortoise conservation specifically and head-starting and translocation programs more generally.

Salamanders known as “newts” that occur along the west coast of North America include four species Taricha torosa, Taricha granulosa, Taricha rivularis, and Taricha sierrae. These newts occur from southern California, all the way to Alaska, and are generally thought to be quite common; however, they  may be experiencing a new threat. Recent online non-peer reviewed reports identify enigmatic mass mortality events across their range. Disease is a leading contributor to global amphibian declines, as evidenced by epizootics caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and may be implicated in newt die offs, but this has not been investigated. In order to document the extent of mass mortality events in western newts and determine whether Bd may be implicated, we conducted two broad surveys and collected disease data at three focal populations  In our first survey, we used community science data from iNaturalist to search for examples of emaciated newts across the entire range. In our second, we targeted herpetologists conducting research within Taricha’s range; and, third, we selected three focal sites where emaciated animals and mass die-offs had been observed. At these focal sites we collected repeated disease diagnostic data and environmental data to determine whether these variables were correlated with emaciated and dying newts (e.g., skin swabs, body condition, and water quality measurements). The three focal populations were located at Point Reyes National Seashore, CA (PR), Briones Regional Park, CA (BR), and Pine Lake, WA (PL). At these sites, mass die offs were reported in 1991 (PR), 2014 (PR), 2020 (BR), and 2021-2023 (PL). The iNaturalist survey included 84,596 observations (2013-2023), of the 5,000 we analyzed, we identified 65 sites with photos of emaciated newts. The herpetologist survey identified 12 sites with the presence of emaciated or dead newts, and 3 sites with mass die-offs.  At our focal study sites, we collected 349 skin swabs at PR ( 243 in 2014, and 106 in 2023), 64 from  PL (2023), and 14 from BR (x in 2020, and 14 in 2023). In addition, we collected 8 swabs from preserved museum specimens at University of California Berkeley (specimens collected in 1991) from PR, all other samples were collected from live animals at the focal sites. At our focal sites, we found higher prevalence of Bd infection and Bd intensity than previously reported in Taricha.  In 2023 we found  34.9% of samples were Bd-infected at PR (37 Bd positive out of 106 total), 46.9% at PL (30 out of 64), and 78% at BR (11 out of 14). Thus, while our data should be considered preliminary, they indicate that Bd may be implicated in emaciation and mass-die offs of western newts. However, we suggest that additional data is needed to understand whether Bd is the causative factor or a secondary outcome of a more potent unknown reason for these events.

We examined the patterns of dispersal and seasonal migration in the California Red-legged frog (Rana draytonii), a federally threatened species. We used radio telemetry techniques to examine the movement patterns and habitat use of post-breeding adults and metamorphs migrating away from an established breeding pond in a grassland and oak-savannah habitat in Sonoma County, CA. By sampling one to three times per 24-hour period, we were able to evaluate the effects of weather, canopy cover, ground moisture, and time of day on migration, forays, and rate of movement across these age classes. We found significant patterns of movement with respect to time of day, precipitation, wind, canopy cover and location relative to known moisture corridors (inundated waterways and wetlands). Patterns of humidity also impacted movements of non-migrating frogs making frequent forays between the pond and adjacent wetlands. Both experienced adults and naïve metamorphs demonstrated a non-random orientation away from the pond, suggesting a preference for specific landscape features. Finally, preliminary results suggest that short-term survivorship of first year metamorphs may be highly dependent on microhabitat use and dispersal timing.

Cascades Frogs are a high elevation specialist, aquatic-breeding amphibian species that inhabits the Klamath Mountains and Southern end of the Cascades Range in Northern California. California Cascades frog populations have been declining for decades. Due to this decline, the species is a California Species of Special Concern and in 2017 was advanced to candidate status pursuant to the California Endangered Species Act by the Fish and Game commission. Three dominant risk factors include introduced predatory salmonid fishes, recent outbreaks of the fungal pathogen Batrachochytrium dendrobatidis (i.e. chytrid fungus) and habitat alteration and desiccation through climate change. To combat these threats, nearly a decade ago CDFW changed their fish stocking policies by ceasing stocking waters that contained Cascades Frogs until a thorough inventory of fish and frog populations could be completed. This management shift has had profound changes on fish distributions in the Klamath Mountains and CDFW is now actively managing fish populations through active fish removal and regulated fish stocking to protect critical Cascades Frog habitats in the face of climate change. This talk will discuss the methods, actions, and expected amphibian benefits from this adaptive, landscape-level management of recreational fisheries in the Klamath Mountains of Northern California.