Research
My research interests include the movements of vertebrates, especially plethodontid salamanders, ranging from fine-scale biomechanics of locomotion to dispersal at the ecosystem level.
Recently, we discovered that arboreal salamanders can parachute and glide. Now, I am interested in exploring ecological applications and comparing aerial behavior in arboreal salamanders from around the globe.
Ultimately, my work examines the life history of amphibians in the broader context of ecological and evolutionary theory with the goal of increasing awareness for conservation.
Model Systems for Amphibian Movement
The crowns of coast redwood trees are home to an impressively biodiverse community. Among the residents of the world's tallest trees: Wandering Salamanders, Aneides vagrans.
I work here because extreme niches feature strong selection and make great focal systems for studying form and function.
High in the Colorado Rockies, where the effects of climate change are accelerated, an isolated population of Arizona tiger salamanders (Ambystoma mavortium nebulosum) exhibits facultative paedomorphosis and cannibalism at the edge of their elevational range.
I work here because range edges are fantastic places to study changes in dispersal and distribution due to changes in climate.
Recent Investigations
Behavior & Biomechanics: Jumping Escape Response in Arboreal Salamanders
wandering salamander jump.mp4
Behavior & Biomechanics: Gliding, Parachuting, and Maneuvering in Arboreal Salamanders
AirrightingParachute_Trim_B.mp4Aneides vagrans executes a crisp air-righting maneuver via a tail rotation, and immediately assumes a parachute posture. Wind speeds are held constant, so the change in vertical direction indicates a change in vertical velocity (i.e. a parachute).
SalTurn.mp4Aneides lugubris makes a sharp banking turn, initiated by the adduction of the right hindfoot and maintained with a parachute posture. Banking turns could help the animals remain in their arboreal habitats after a fall or jump by guiding them to the trunk or lower branches.
Morphology, Form & Function: Using fluid dynamics to investigate aerodynamics
Coming Soon...Physiology: Investigating properties of specialized toes
These gliding salamanders captivate and inspire the public, attributes that can be used to promote redwood conservation and restoration! It has sure inspired me...
Restoration Ecology: Seeding the canopy of Sequoia Park Zoo's Canopy Skywalk
In 2023, I was honored to receive a Sequoia Park Zoo Conservation and Research grant. My time will be spent collecting and relocating wayward fern mats to tree crotches along the Redwood Skywalk. Over many years, the mats will grow and salamanders should move in, creating a natural interactive exhibit and educational opportunity for zoo visitors.
Fern mats are home to a wide range of native flora and fauna. So, in addition to increased satisfaction for zoo visitors, the entire ecological community will benefit from the return or introduction of fern mats to this canopy.
Dispersal and Distribution: Alpine Tiger Salamanders
Anthropogenic climate change is accelerated at high altitudes, and is already drastically affecting hydroperiods and temperatures of subalpine ponds in the Rocky Mountains. How will these changes impact amphibians at the edge of their elevational range with nowhere else to go?
Specifically, I am interested in changes to annual migration patterns of metamorphic Arizona tiger salamanders and within-pond distribution of fully-aquatic paedomorphs and larvae. This research will help us predict and understand how future distributions of amphibians at range edges will impact competition, disease ecology, and more.
By uniquely marking the tiger salamanders with Passive Integrated Transponder (PIT) tags, a slightly smaller version of your dog's 'microchip', we are able to remotely detect their locations and movements. Amphibians are not always surface-active and thus can be hard to find by visual cues alone, but the PIT tag transmissions can be detected through soil, water, and vegetation. Handheld antennae and wands are used to scan the warm, shallow pools called thermal zones that these high alpine ectotherms rely on for thermoregulation.
GIS maps of observed tiger salamander locations suggest a clumped distribution within ponds. This dense clustering has implications for intraspecific competition, cannibalistic size-structure dynamics, and disease outbreak. Interestingly, we have learned that this remote detection method is capable of finding tagged animals that have evaded capture by researchers for over a decade! The improved accuracy and enhanced scale of our mark-recapture data as a result of PIT telemetry will be critical to understanding how changing temperatures and hydroperiods will influence the ecology and evolution of these environmental sentinels.
