Frequent population declines, high dietary requirements for protein, a
nd the low quality of proteins in agricultural grains led us to hypoth
esize that essential amino acid (EAA) deficiencies were common in nort
hern bobwhite (Colinus virginianus) foods. We analyzed amino acid conc
entrations of 21 northern bobwhite foods and compared them with dietar
y requirements to derive values that reflected the foods' ability to m
eet daily bobwhite requirements of 10 EEAs. Despite adequate concentra
tions of crude protein, deficiencies of EAAs were detected in seeds of
all species analyzed. Legumes offered the best mix of EAA, and grasse
s the poorest. Deficiencies of EEAs relative to maintenance requiremen
ts of adults ranged from 13% in legumes to 98% in grasses. About a thi
rd of the total nitrogen pool was composed of nonprotein nitrogen with
values ranging from 25% for queensdelight stillingia (Stillingia sylv
atica) to 44% for redroot amaranth (Amaranthus retroflexus). Computed
biological values (ratio of EEA concentrations in seed protein to resp
ective amounts in whole egg protein) ranged from 69 (netleaf hackberry
[Celtis reticulata]) to 93 (erect dayflower [Commelina erecta] and wo
olly croton [Croton capitatus]). Amino acid profiles indicate forage q
uality better than crude protein estimates.