1941
In most areas of habitat, the Downy Woodpecker is a year-round resident, but at northern extreme of range, the Downy Woodpecker may move south for the winter.
Clay is a common componet of soil, it has always been known about, as long as humans have existed they have known about clay. The same answer could have been given if you had asked when was wood, or water discovered.
mickey mouse year:1995
yttrium was discovered in the year 1794.
In the year 1902. Dr. Still discovered ADHD.
It was discovered in 1866.
it was discovered 1347
ATOMIC NUMBER YEAR IN WHICH IT WAS DISCOVERED? it was discovered in 1913 by British physicist Henry Mosely
argon was discovered by Dr.william Ramsay of Scotland in the year 1894.
DNA was discovered in 1953.
1825 aluminum was discovered.
sulfur was discovered in 1777