Richard D. Durtsche

Learn More
Invasive shrubs can increase ecosystem transpiration and potentially affect hydrology in forested ecosystems. We examined two adjacent sites in a wetland forest in northern Kentucky, USA. One site contained little Lonicera maackii (Amur honeysuckle), while the other contained considerably more. Using Granier (thermal dissipation) and heat balance probes,(More)
Ontogenetic shifts from insect consumption by juveniles to plant consumption by adults are rare in the herbivorous lizard family Iguanidae. My investigations on diet and digestive tract anatomy of the iguanid lizard Ctenosaura pectinata show that this species has an ontogenetic diet shift. Insects were rare in adult diets but constituted 86.5% (by volume)(More)
I tested the hypothesis that an animal with an ontogenetic diet shift must have different digestive efficiencies for foods that correspond to its diet shift, so that nutrient and energy extraction are maximized. The iguanine lizard Ctenosaura pectinata undergoes an ontogenetic diet shift from eating insects as a juvenile to plants as an adult. When fed six(More)
The natural diet of northern temperate tadpoles is a largely neglected area of study. We investigated the natural diets in three anuran larvae, the wood frog (Rana sylvatica), the American toad (Bufo americanus), and the spring peeper (Pseudacris crucifer), from several ephemeral ponds in northern Minnesota. Previous laboratory studies suggest that these(More)
I examined the foraging behavior during the breeding and non-breeding seasons, May and July 1986, of the fringe-toed lizard Uma inornata (Iguanidae). During the breeding season males differ from females in their diet and in their foraging time strategy, males exhibiting time minimization and females energy maximization. In May, plant associated foods were(More)
Green roofs are emerging engineered ecosystems that provide multiple benefits, but many are constructed with nutrient-rich substrate and have been found to leach out high levels of phosphorus (P) in runoff. It is unclear, however, how long green roofs act as sources of P or what mechanisms are responsible for these net losses. We measured P concentrations(More)
  • 1