News

Use of Mark-Recapture Techniques to Estimate Turtle Populations at the UWM Field Station

Information on long-term trends in reptile populations can yield useful conservation information. This is particularly true because long-term monitoring projects that involve reptile populations are relatively uncommon, especially in Wisconsin. In 2006 we began an annual turtle survey on the Field Station Grounds, lasting for three days each year in late May/early June. We set turtle hoop traps approved by the Wisconsin DNR in several locations, which we checked daily during annual surveys. All of the animals captured were marked via marginal scute notches, following a well-established system.

Factors Controlling Diffusive CO2 Transport and Production in the Cedarburg Bog, Saukville, Wisconsin

Wetlands are vital components of the carbon cycle containing an estimated 20-30% of the global soil carbon store. The Cedarburg Bog of southeastern Wisconsin boasts a myriad of wetland habitats including the southernmost string bog found in North America. Carbon dioxide (CO2 ) behavior in these systems is the response of multiple interdependent variables that are, collectively, not well understood. Modeling this behavior in future climate scenarios requires detailed representation of relationships within highly diverse environments.

Handedness and Behavioral Lateralization in Anurans

Surviving and reproducing successfully depend on an animal’s ability to process information from the environment and respond adaptively. In many situations an individual must perform different activities at the same time (i.e. foraging and predator vigilance). If these activities compete for the same computational resource, for example, if both require visual or auditory attention, the brain’s ability to process the information may constrain the performance of both tasks.

Behavioral Ecology of Color Change in Gray Treefrogs

Gray treefrogs (Hyla versicolor) have amazing color change ability, and can range from dark brown to bright green. Yet, nothing is known about the distribution of body color in nature, or whether frogs choose their resting perches based on their body color, or adjust body color as a function of ambient color or temperature. Here, we examine the behavioral ecology of color change in gray treefrogs. Color change can function to hide the individual from predators (crypsis), or to make the individual obvious for conspecifics (conspicuousness). In addition, in ectotherms (cold blooded animals), body color may help with thermoregulation (darker colors heat up better, brighter colors increase reflection and stay cooler).

Audiovisual Integration and Leader Preferences

Humans perceive several sounds in close temporal succession as a single event originating from the location of the leading sound, a trick played by the auditory system to improve sound localization. Surprisingly, a visual cue associated with the leading sound enhances sound localization, while a visual cue associated with the lagging sound inhibits it, suggesting that auditory spatial perception in humans is a fundamentally multisensory process.

Multimodal Communication in Eastern Gray Treefrogs, Hyla versicolor

Signal production and reception often encompass various modalities of communication. For example, a calling frog cannot but produce a visual component as it inflates and deflates its vocal sac to emit an acoustic signal. A frog calling in a pond also creates water surface waves, and calling on a branch he creates vibrational signals. Thus, a simple “acoustic signal” actually encompasses three modalities (acoustic, visual and surface wave / vibrational).

Parasitism and Ornamentation: a Within-individual Study in the Common Yellowthroat

Elaborate ornaments are hypothesized to honestly signal individual quality, including the ability of an individual to combat parasitic infection. Although there have been many studies of this hypothesis, the results of these studies have been mixed. One explanation for these varying results is that measures of ornaments and parasitic infection intensity are typically obtained only once for each individual. Therefore, correlations between ornamentation and parasitic infection intensity do not consider within-individual relationships, which may differ from between-individual relationships.

Experimental Reduction in Bumble Bee Visitation Promotes Increased Wasp Visitation to Whorled Milkweed (Asclepias verticillata)

Changes in the local pollinator community may shape the dynamics of plant-pollinator interactions. Since the quality of pollination services often varies markedly among pollinator species, the consequences of pollinator declines for plant reproductive success may be unpredictable. Therefore, changes in the composition of visiting pollinators, in terms of their pollination efficiency and visitation rates, may play a significant role in determining the effect of pollinator loss on plant reproductive success.

The Carnivorous Pitcher Plant Sarracenia purpurea Harbors a Diverse Eukaryotic and Bacterial Flora to Aid Prey Digestion

The pitcher plant Sarracenia purpurea grows in nutrient-deficient wetlands such as Cedarburg Bog and supplements mineral nutrition by carnivory. Newly formed pitchers are sterile, but fill with rainwater, in which insect prey drown. Within the pitcher detrital food web, invertebrates begin macroscopic breakdown of prey while microbial hydrolytic enzymes (chitinases, phosphatases, proteases) digest and release nutrients, prior to absorption by the plant.

Climate Impact on Groundwater Flow Processes in the Cedar Creek Watershed and Cedarburg Bog

A local-scale groundwater-flow model of the Cedar Creek Watershed and Cedarburg Bog area was constructed to determine the effects of future changes in temperature and precipitation on water resources. The Cedar Creek Watershed is a 330 km2 subbasin of the Milwaukee River Watershed located about 30 km north of Milwaukee. The importance of this watershed lies in its location at the sub-continental divide separating the Mississippi River Basin from the Great Lakes Basin.