Text of a notice in today's science section of the Times: A Chickadee Mating Zone Surges North (NY Times pg D-2, 3/18/2014) In a long, narrow strip of territory from Kansas to New Jersey, two closely related species of chickadees meet, mate, and give birth to hybrid birds. Now scientists are reporting that this so-called hybrid zone is moving north at a rate that matches the warming trend in winter temperatures. "It has moved north by about seven miles in the last 10 years," said Scott Taylor, an evolutionary biologist at the Cornell Lab of Ornithology at Cornell University. The northward movement of the strip "corresponds closely to warming global temperatures," Dr. Taylor said. "The fact that these little birds are experiencing this makes it really relatable." (The species are the Carolina chickadee, from the South, and the black-capped chickadee, from the North. The scientists, who reported their findings in the journal Current Biology, relied on blood samples drawn from chickadees in Pennsylvania from 2000 to 2002 and from 2010 to 2012, and on sightings of hybrid chickadees recorded in the citizen science database eBird. They found that hybrids were sighted in areas where the average temperature in winter was 15 to 19 degrees Fahrenheit (minus-9 to minus-7 Celsius)--the same readings as a decade earlier, but in a zone seven miles north of the 2000-02 sightings. The adaptability of the chickadees is impressive, Dr. Taylor said, but less mobile organisms that cannot move as fast may be suffering. For these organisms--like small mammals, insects, and plants--the warming temperatures could have serious implications that are not immediately apparent, he said. SINDYA. N. BANHOO * * * * * This is another study confirming what birders have noticed in Ohio for generations. Here in the center of the state, Wheaton in 1882 wrote that the Carolina chickadee did not winter this far north at the time, only the black-capped. By 1903 Lynds Jones wrote that Carolinas still did not breed north of Columbus. In 1924 E.S. Thomas wrote he had never seen a black-capped chickadee in Columbus--all chickadees throughout the year were Carolinas, but he was later to witness incursions of black-caps in Columbus, with one way down in Hocking County in 1957. In 1961, it was still called "plentiful in town by December" (American Birds 16(1):41), and Trautman had been counting 50+ black-caps a day in November. Their numbers retreated into small ones by the '80s, and in recent decades they have been mostly absent, with only a handful of reports, always in winter. Overall, the rate of movement posited by Dr. Taylor seems to match our experience with other species. During those decades the reliable black-capped range has been retreating north, with the "chickadee line" advancing from here to Killdeer Plains to Rte 30, and now folks in Wooster remark on the growing number of chickadee hybrids. The frontier is moving north--though maybe not at the measured pace the Cornell NY Times article suggests--but overall steadily. Folks in Pennsylvania have noticed the same thing, and they have done a lot more careful work. It is significant that the changes in bird distribution over the past 150 years, well verified as it was for most of that time by museum specimens, shows this. There are lots of Ohio breeding species once regarded as "southern birds"---mockingbird, black vulture, egrets, barn owl, titmouse, w-b nuthatch, red-bellied woodpecker, etc--that have expanded their ranges into and beyond Ohio in good numbers. I had to smile at the inclusion of data from eBird in the description of the article--which I have not read this, but plan to seek at the University library. In other forums like ours, a number of folks around the country have questioned how reliable eBird data might be in comparison to the blood samples in this study. I know this is a pet project of Cornell's, and relentlessly publicized, but no scientist is going to trust the IDs of chickadees--including hybrids and back-crosses!--reported by random eBirders of varying abilities in such a study. Even if all those reporters happened to be correct in their field identifications, eBird lacks, and seems to ignore, historical records, so is doubly inadequate to the task. A question for the shrinking number of global-warming skeptics: over the sliver of time for which we have records, the ranges of southern bird species seem to be expanding north. Can you think of any northern species making inroads on a similar scale in the south? The only example that occurs to me is the bobolink... Bill Whan Columbus ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Please consider joining our Society, at www.ohiobirds.org/site/membership.php. Our thanks to Miami University for hosting this mailing list. You can join or leave the list, or change your options, at: listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]