The male European Starling's bill turns yellow in the Spring. I found this one with its bill open on a very hot and humid day.

"In 1890-1892, about 100 starlings were released in New York City's Central Park as part of an effort by the acclimatization society to introduce all birds mentioned in Shakespeare's writings to North America. There are now more than 200 million starlings across most of the continent." - from Urban Bird Studies website