Endangered act.
D000818:Animals; D001717:Birds / Q000502:physiology; D003247:Conservation of Natural Resources / Q000331:legislation & jurisprudence* / Q000639:trends; D004463:Ecology / Q000331:legislation & jurisprudence* / Q000592:standards / Q000639:trends; D035082:Federal Government; D011157:Population Dynamics; D014481:United States