Adventitious coloration Superficial staining on the body. For example, the heads and necks of swans (genus Cygnus) may be stained a rusty colour by iron in the water. Search Bird Dictionary From Peter Weaver's Birdwatcher's Dictionary Copyright © 1981 by Peter Weaver
Search Bird Dictionary
From Peter Weaver's Birdwatcher's Dictionary Copyright © 1981 by Peter Weaver