North American Birds

VOLUME 69 NO3 2016

A Quarterly Journal of Ornithological Record Published by the American Birding Association. The mission of the journal is to provide a complete overview of the changing panorama of our continent’s birdlife.

Issue link: http://nab.aba.org/i/778845

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Figure 2. Very few of the Tennessee and Kentucky re- gion's Glossy Ibis reports have come during the summer season. This nicely documented adult was present near Prospect, Oldham County, Kentucky on 27 June 2015. Photograph by Karen Bonsell. V O L U M E 6 9 ( 2 0 1 6 ) • N U M B E R S 3 / 4 343 T H E C H A N G I N G S E A S O N S : R E T R O S P E C T ture for ocean surfaces globally was 0.74° (1.33° F) higher than the twentieth-century average, which broke the previous record of 2014 by 0.11° C (0.20° F). Ocean tempera- tures for every single month in spring and summer were record high for those months, tied in part to a very strong El Niño event. Before 2015, the highest monthly anomaly on record for the global oceans occurred in September 2014 and was mentioned in this column, and we will break with our chrono- logic tradition here and note that August, September, and October 2015 all broke all-time monthly records, for any month, with positive anomalies of 0.78°, 0.83°, and 0.86° C, respectively. The strengthening El Niño in the Pacific Ocean that started in spring was responsible for part of this trend, but much warmer-than-average and record- warm sea surface temperatures were re- corded in parts of every major ocean basin. Global land surface temperatures in 2015 also broke records: the planet's land surface was 1.33° C (2.39° F) above the twentieth- century average, breaking the previous re- cords from 2007 and 2010. As air tempera- tures rise, glaciers and ice sheets melt, but warming ocean water itself also expands, so sea levels rise for multiple reasons. Sea levels have been rising at an increasing rate since at least 1900, at about 15.24 mm (0.6 in.) per decade through 1991. Since 1992, however, the rate of rise has doubled, to 30.48 mm (1.2 in.) per decade—a sig- nificantly larger rate than at any other time over the past 2000 years. Scientists expect the rise to continue for centuries, no matter what measures we take in the near term. For the above data, I appreciate the excellent work done by the National Climatic Data Center (National Oceanic and Atmospheric Administration), as always. I was unable to get specific summary data for Canada for these seasons, unfortunately. If there is a common theme among the 2015 spring and summer regional reports, it is the frequent mention of scores of spe- cies well north of expected range. Clearly, our experience of birds indicates that some species in our avifauna have moved north- ward—for instance, birds of the southern- most U. S. states have expanded or at least crept into the next tier, or two, of states, while birds of the central states are now seen more often in the northern. But the changes in status vary widely among spe- cies and certainly must depend on numer- Figure 3. This second-year White Ibis, photographed at Ocean City, Cape May County, New Jersey on 22 June 2015 and probably already present for several days, led an unprecedented incursion of mostly young birds into Delaware and southern New Jersey. Photograph by Brian Kushner.

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