Road Crossing Structures for Amphibians and Reptiles: Informing Design through Behavioral Analysis
Every day, millions of vertebrates are killed on roads. Road traffic causes significant amphibian and reptile mortality, which could be mitigated through the installation of road crossing structures that facilitate safe passage, but only if reptiles and amphibians are willing to use them. Through a series of behavioral choice experiments with two species of frogs and two of turtles, I examined how aperture diameter, substrate type, length, and light permeability influenced individuals’ preferences for specific attributes of crossing structures, and how individuals responded to various heights of barrier fences. Tunnels > 0.5 m in diameter lined with soil or gravel and accompanied by 0.6 – 0.9 m high guide fencing would best facilitate road crossing for these and likely other frog and turtle species.
Teaching Observation and Notation
Over the past decade, I have taught and lectured on various aspects of art, design, and ecology to graduate and undergraduate students. Most recently, I developed and co-taught, The Art of Scientific Observation at The Storm King Art Center. This week-long course for summer science students at Black Rock Forest Consortium focuses on the field journal. Throughout history, both scientists and artists have used field journals to note their observations of the natural world and develop their ideas. Such visual and written notation requires keen observational skills, and the practice of recording in journals engages and develops lateral thinking capabilities. Weaving together science and art, this class offers students an opportunity to combine field ecology and artistic practice. Through explorations of Storm King’s forests, fields, ponds, and sculptures, the class introduces students to observational and notational methods.
Waved Albatross: Mapping Nesting Density and Distribution
The critically endangered Waved Albatross (Phoebastria irrorata) has declined due to human-induced threats. Long-line fishing is particularly damaging; individuals are often killed when they pick up and become ensnared on baited long-line fishing hooks, which stretch for miles through the seas. This albatross breeds only on the island of Española, yet little is known of the status of several nesting populations. In 2008 I was part of a team of scientists supported by the Charles Darwin Research Station and American Bird Conservancy to conduct a survey of nesting albatross and woody vegetation in the central and coastal colonies. We found evidence of a strong interaction between the distributions of vegetation and nesting albatross and designed a vegetation manipulation scheme that could better elucidate whether woody vegetation is limiting albatross nesting.
Española Tortoises: Tracing Distribution and Health
The population of Giant tortoises (Geochelone nigra hoodensis) on Española Island once numbered approximately 3000, but centuries of exploitation and invasion reduced population sizes to approximately 13 individuals by the 1960s. At that point, all remaining tortoises were transferred to an off-site breeding center while goats, a significant threat to tortoise survival, were eradicated on the island. A reintroduction program has transferred offspring of the original tortoise population back to Española since 1971, and reproduction now occurs on the island as well. The population of tortoises has increased to approximately 1000 individuals, but information on the status of the tortoise population and the ecology of the island is critical to the continued success of restoration efforts. In 2007, I joined a team of scientists sponsored by the Charles Darwin Research Station and the Galápagos National Park to conduct a survey of tortoise population sizes, map tortoise distribution, and gather baseline health data. Future work will explore the trajectory and implications of this loss and restoration of the tortoise as “ecological engineer” on the island and its native species.
Galápagos Rail: Surveying a Population and a Landscape
In this study, sponsored by the Charles Darwin Research Station, Galapagos National Park, and University of Delaware, I was part of a team that surveyed and documented the population and habitat of Galápagos rails, Laterallus spilonotus on Isla Santa Cruz. Currently, the population status of this elusive bird is unknown, and invasive species threaten the few existing populations. We re-surveyed an existing population on Santa Cruz Island and examined the influence of an invasion of the species’ habitat by the red-barked quinine tree (Cinchona pubescens). By comparing surveys from 2000 and 2007, we discerned that rail occupancy and abundance declined over time. Restoration of native vegetation could positively impact this population.
Nick’s Head Station: Restoration and Conservation
Nick’s Head Station is a 680 hectare farm on the North Island of New Zealand. Over the past century, deforestation, intensive livestock farming, and wetland drainage profoundly damaged the land. I collaborated with Nelson Byrd Woltz landscape architects and Ecoworks New Zealand on the design and implementation of a conservation master plan for this culturally and ecologically significant site. Implementation combines a sustainable farming endeavor with large-scale ecological restoration and includes a 1.5 mile road design, 30 acre wetland reconstruction, a tuatara and gray petrel reserve, a reforestation program, and native plant arboretum.