By Ted Cox | January 17, 2017 12:02pm | Updated January 20, 2017 10:48am
LINCOLN PARK — An endangered bird continues to thrive in the area in and around Lincoln Park Zoo, even though zoo officials noticed a considerable drop in the number of their nests last year.
The black-crowned night heron is considered endangered in Illinois, but it has thrived in Lincoln Park, especially in and around the zoo.
"Birders are concerned," said Carolyn Marsh, a Northwest Indiana bird watcher who reported the drop on the Illinois Birders Exchanging Thoughts website.
Even so, researchers with the zoo's Urban Wildlife Institute counted just 191 of the herons' nests last year, down from 271 in 2015, 263 the year before and even 211 in 2011.
Nonetheless, the zoo reported that "although we had less adults than last year, we still had about the same amount of young as last year. The adults were highly successful breeders this year and the weather cooperated so that we had less deceased young compared to previous years."
"It’s natural for populations to fluctuate from year to year," institute ecologist Mason Fidino said Tuesday. "This year’s count of black-crowned night heron adults is slightly lower than the previous year but is not cause for concern — even stable populations fluctuate around the population level that the environment is able to sustain."