Range margin shifts of birds revisited - the role of spatiotemporally varying survey effort
Heini Kujala, Ville Vepsalainen, Benjamin Zuckerberg, Jon E Brommer
GLOBAL CHANGE BIOLOGY | WILEY-BLACKWELL | Published : 2013
Global climate warming is predicted to lead to global and regional changes in the distribution of organisms. One influential approach to test this prediction using temporally repeated mapping surveys of organisms was suggested in a seminal paper by Thomas & Lennon (1999, Nature). The Thomas & Lennon approach corrects observed changes in the range margin for changes in the range size, and thus potentially controls for other broad-scale environmental changes between surveys, however the approach does not necessarily account for potential biases in sampling effort. To verify whether the issue of variation in sampling effort affects empirical estimates of shifts in range margin, we reanalyzed al..View full abstract
Our deepest gratitude goes to all the volunteers behind atlas data - without their effort it would not be possible to do this study. We thank British Trust of Ornithology (BTO) for supplying the data of Great Britain, and Kimberley Corwin and John Ozard for supplying New York State atlas and effort databases. H. K. would like to acknowledge LUOVA Graduate School and Finnish Cultural Foundation for funding. J. E. B. was supported as an Academy Researcher (1131390). We thank Steve Beissinger and an anonymous reviewer for their valuable comments on the earlier version of this work. Original idea for this study came from H. K. and V. V. Analyses were conducted by H. K., V. V., and B. Z., and J. E. B. produced the model. Writing was done by H. K. and J. E. B. with input from V. V. and B. Z.