Samuel Riffell

Using web-based instruction to improve large undergraduate biology courses: an evaluation of a hybrid course format

We developed a hybrid course format (part online, part face-to-face) to deliver a high-enrollment, introductory environmental biology course to resident (living on or near campus), non-science majors at a large, public university. The hybrid course was structured to include bi-weekly online assignments and weekly meetings in the lecture hall focused on active-learning exercises. To evaluate the effectiveness of the web-based component of the hybrid course, we taught the hybrid course simultaneously with a traditional course in which we used passive lectures to cover material in the online assignments. Both courses received the same active-learning activities in class. Students in the hybrid course reported that the quality of interaction with the instructor was high, that they read the text more often and studied in groups more frequently. Performance on a post-course assessment test indicated that the hybrid course format was better or equivalent to the traditional course. Specifically, online assignments were equivalent to or better than passive lectures, and that active-learning exercises were more effective when coupled with online activities. Performance gains were greater for upperclassmen than for freshmen, indicating that hybrid course formats might be a superior option for upperclassmen when satisfying general science requirements.

AREA AND HABITAT RELATIONSHIPS OF BIRDS IN GREAT LAKES COASTAL WET MEADOWS

Although relationships of birds to patch area and habitat characteristics have been dominant themes in avian ecology over the past few decades, relatively little is known about these relationships in wetland-dominated landscapes of the Great Lakes coastline. During 1997 and 1998, we surveyed birds and measured habitat characteristics along transects in wet meadows associated with the northern Lake Huron shoreline (NLHS) in the Upper Peninsula of Michigan. Using a suite of multivariate techniques, we related abundance and presence/absence of individual species to wet meadow area and habitat characteristics. Nine species were positively associated with increasing wet meadow area, which underscores the importance of large wetlands to avian conservation in the region. Bird variables also were related to habitat characteristies. Higher values of bird variables were generally associated with a suite of characteristics: more robust and dense grass/sedge vegetation, structural diversity in the horizontal and vertical planes, and increased frequency of willow shrubs. Individual species that require particular aspects of these characteristics for nesting or foraging were associated with principal components containing those aspects. In the NLHS, large wet meadows that possess these characteristics would support the greatest diversity and benefit the majority of species. However, conservation efforts that focus only on these traits will not be sufficient for all species because habitat requirements for some species are very specific (e. g., open water for mallard), and for others, habitat preferences may change from year to year in response to lake-level changes. While our results provide important insights, continued research is needed to further the successful conservation and management of birds in Great Lakes coastal wetlands.

Birds in North American Great Lakes coastal wet meadows: is landscape context important?

Landscape context can influence species richness, abundance, or probability of patch-use by birds. Little is known, however, about the effects of landscape context on birds in wetland-dominated landscapes. This lack of knowledge is alarming because many wetlands are threatened by development and other human impacts, while serving critical functions as migratory, breeding and foraging habitat. To address this lack of knowledge, we censused birds in North American Great Lakes coastal wet meadows located along the northern Lake Huron shoreline in Michigan (USA) during 1997 and 1998. Using a suite of multivariate techniques, we first accounted for effects of area and within-patch habitat characteristics before testing for effects of landscape context. Most bird variables were significantly related to landscape context, and two major patterns were apparent. First, avian species richness, abundance, and probability of patch-use by some species were higher for wet meadows located in complex contexts (adjacent to many patch types) compared to simpler contexts (adjacent to only one patch type). Second, these variables were higher for wet meadows located in wetland contexts compared to contexts that were terrestrial and road-impacted, dominated by open water habitats, or dominated by forested wetland habitats. Conservation plans for wetlands have focused on saving large wetlands and creating the vegetative habitat structure required by birds, but they should go further and explicitly consider the landscape context of wetlands as well. Specifically, wetlands located in complex and/or wetland contexts should have a higher conservation value than similar wetlands located in simpler, more terrestrial contexts.

BIRDS IN DEPRESSIONAL FORESTED WETLANDS: AREA AND HABITAT REQUIREMENTS AND MODEL UNCERTAINTY

Forested wetlands are important habitat for many bird species, but data about area and habitat relationships of birds in depressional (i.e., non-riverine) deciduous forested wetlands are scarce. Depressional forested wetlands are often surrounded by larger, continuous patches of upland forest, and it is not clear whether this surrounding forest should be considered part of the forested wetland. To contribute regional data to this question, we sampled birds and vegetation in depressional forested wetlands in southern Michigan, USA. Results indicated that the wetland per se should not be considered separate from the surrounding forest because forest area and forest characteristics were the most important predictors of richness and abundance of wetland-associated birds. Conversely, wetland area and wetland characteristics were important for some upland species. Because spatial clustering and model selection uncertainty are often encountered by wetland scientists, we describe analytical methods used to deal with these problems.