I haven't been following this thread much but did read Phil Chu's comments. I responded to Phil but decided to share some of my comments with the group as well.
I checked my climate models for Northern Bobwhite. The current (as of late 1980s) climate model shows the climate in northern Iowa, in general, to be marginal (40% probability of occurrence) for Northern Bobwhite with small pockets of potentially suitable climate extending into part of MN (including the approximate area the birds were seen). The models also project that, over time, the climate over the entire state of MN would become suitable for Northern Bobwhite. Given current amounts of regional warming then it is POSSIBLE that parts of northern Iowa and southern MN are now climatically suitable to support Northern Bobwhite populations. Incidentally, in this area at the edge of current climatic suitability you could reasonably expect the climate to be suitable in some years and not in others. Whether these birds have naturally colonized the state or not is a matter of conjecture. I'm just pointing out the possibility of future natural colonizations. This is going to make the task of bird record committees that much harder. The last time I checked (data through 1996) the center of range of Northern Bobwhite had not shown any northward trend. However, the amount of warming has increased significantly since then and PDO and NAO have also both changed state (sign) which impacts precipitation patterns. I will be looking at data through 2002 this fall so will have better information then. Jeff Price, Ph.D. Director of Climate Impact Studies American Bird Conservancy Boulder, CO [email protected], [email protected] www.abcbirds.org ===== Jeff Price Boulder, CO [email protected] __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com
