The ability to use monitoring data to answer questions about how butterflies are impacted by a changing environment is a critical component of NAB-Net. Most groups monitor for two key reasons: 1) to educate and recruit more people into the ranks of butterfly enthusiasts and 2) to track changes in butterfly populations over space and time.
To achieve this second goal, we need the ability to answer specific questions like: Are population sizes changing over time? Do specific human activities influece butterfly population levels? Can we link changing populations to specific changes in the environment? Monitoring data is the only source to be able to answer these questions on large scales and over long time periods. However, the fact that protocols tend to be more casual, survey placement less "random" (or at least stratified), and experience levels more variable - adds substantial noise to data that is already noisy from the natural fluctuations of butterfly populations. Further - the sheer volume of data, while a goldmine for answering questions can be difficult to handle.
Our goal is to be a hub for the best methods that have been or are currently being developed to help get as much information as possible from these data sets. As the field of statistics grows and changes along with the questions of the highest priority to researchers, conservationsists and land managers - the analytical challenges are always shifting as well. As a group, we are currently focused on the following goals:
Baskerville, G. L., & Emin, P. (1969). Rapid estimation of heat accumulation from maximum and minimum temperatures. Ecology, 514-517.
Calabrese, J. M. (2012). How emergence and death assumptions affect count-based estimates of butterfly abundance and lifespan. Population ecology, 54(3), 431-442.
Matechou, E., Dennis, E. B., Freeman, S. N., & Brereton, T. (2014). Monitoring abundance and phenology in (multivoltine) butterfly species: a novel mixture model. Journal of Applied Ecology. doi: 10.1111/1365-2664.12208
Soulsby, R. L., & Thomas, J. A. (2012). Insect population curves: modelling and application to butterfly transect data. Methods in Ecology and Evolution, 3(5), 832-841.
Zalucki, M. P. (1982). Temperature and rate of development in Danaus plexippus L. and D. chrysippus L.(Lepidoptera: Nymphalidae). Australian Journal of Entomology, 21(4), 241-246.
Zonneveld, C. (1991). Estimating death rates from transect counts. Ecological Entomology, 16(1), 115-121.