The Virginia Academy of Natural Science has been meeting at Norfolk State University this week, and Thursday morning was the Natural History and Biodiversity section (Nancy Moncrief and I presented a poster on our squirrel research in this section). There were a total of seven talks in the section, six of which were presented by students. There were several talks on dragonflies. J. Beard and D. Waller looked at perch height preferences for dragonflies, and for the taxa in their study (including Libellula, above) did not find any support for previously published hypotheses that larger species prefer higher perches.
In a well designed series of experiments S. Snyder and D. Waller looked at whether or not dragonfly nymphs could learn to associate particular substrates with food, with the idea that this might control their distribution in natural settings. After establishing that the nymphs don’t have any default substrate preference (except not liking bare plastic) they would always feed the nymphs on a particular substrate and then see if they preferred to sit on those surfaces. Their preliminary data suggest that the nymphs can learn to associate substrates with food, but they need a lot of training to do so. Interestingly, there’s some indication they lose patience quickly; they’ll go to the substrate they’ve associated with food in the past, but if they don’t find any they give up on it pretty quickly.
L. Campbell, J. Beard, and D. Waller looked a dragonfly egg-laying patterns, finding that non-territorial species tend to lay their eggs in a more scattered pattern in open water, while territorial species prefer to cluster their eggs in vegetation.
J. Schmude and D. Waller presented preliminary data on whether or not carrion beetles have carcass size preferences. At least some species seem to prefer certain carcass sizes.
J. Eggleston and R. K. Rose looked at changes in meadow vole populations over time at two sites in coastal Virginia. Even though the sites are close to each other, there are some differences between them. Interestingly, at one of the sites the meadow vole population crashed (about a 50% drop in one year), but the cause of the crash isn’t immediately apparent.
T. A. Egerton, H. G. Marshall, and K. C. Filippin looked at the effects of tropical storms Irene and Lee on algal blooms in the James River. It seems that immediately after the storms there was a crash in the abundance of algae, but the diversity increased. As a side note, they mentioned that the seasonal dinoflagellate bloom in the Chesapeake Bay occurred 2 months earlier in 2012 than normal, because of the increased temperatures in 2011.
C. A. Kauffman, S. Quinn, and T. C. Wood discussed the use of camera traps in monitoring wildlife. This is a nice technique, in that it produces large amounts of data and is relatively noninvasive. It does present its own unique difficulties, however, such as black bears trying to use the cameras as toys.
There were also two talks from winners in the Virginia Junior Academy of Science competition. Caroline Robinson looked at possible correlation between wind direction and water level in tidal inlets, and in a particularly impressive series of experiments Camille Yoke studied the rolling stability characteristics of different shape boat hulls.