Bony tissues that were analyzed were the right foot, 
ones of the right leg (femur, fibula, and tibiotarsus), 
kull (including beak), and sternum. Skeletal muscles 
itilized were those of the right leg (all muscles attached 
o the femur, fibula, and tibiotarsus) and the larger 
nuscles of the right half of the sternum (pectoralis 
horacica, supracoracoideus—ventral head, and cora- 
obrachialis posterior, see Hudson & Lanzillotti 1964: 
3-15, for detailed descriptions). A sample of fat was 
)btained from deposits around the neck, on the postero- 
entral surface of the sternal muscles, and in the 
‘iscera. Organs excised were the adrenals, brain, bursa 
from juveniles only), gizzard (muscular portion and 
ining were separated), heart, intestine (including colon 
md ceca), kidneys, liver, lungs, pancreas, spleen, 
eproductive organs (ovary and oviduct), thyroids, and 
hymuses. Samples of feathers were obtained by clip- 
ing the larger feathers, mainly the primaries and 
econdaries, from both wings. 
After being excised, the body parts were carefully 
reed of all extraneous material and rinsed, if necessary, 
n doubly distilled water (ion concentration < 5 ppm). 
‘hey were then rolled on a paper towel to remove 
xcess moisture and blood. The heart and liver were 
pened to remove clots of blood, and the gall bladder 
yas removed from the liver. After most of the con- 
>nts were stripped from the intestine, ceca, and colon, 
nese Organs were opened and thoroughly rinsed. Bony 
issues and feathers were dried in an oven (65° C.) 
ntil successive weighings indicated they had stopped 
ysing weight. The other body parts were weighed 
nmediately after being excised and cleansed. All body 
arts were placed in polyethylene bags or vials and 
tored in a freezer. 
Analyses of the body parts were conducted in the 
pectrographic Laboratory, Department of Physics, 
Iniversity of Tennessee, Knoxville. The samples were 
yawed, then pooled according to body part, geo- 
raphical region, and, when the samples were large 
nough, age of the birds. (The smaller body parts — 
ll internal organs except gizzard muscles, intestines, 
nd livers—were pooled at the time they were extracted 
‘om the birds. Leg muscles and sternal muscles were 
ooled on a weight basis after they had been reduced 
» ash.) Pooling was necessary because (1) many of 
1¢ body parts were too small to be adequately analyzed 
idividually, and (2) the cost, in time and funds, of 
nalyzing each body part of each bird was prohibitive. 
All samples were weighed immediately before ashing 
rocedures began. The resulting weights, which seldom 
iffered more than 3 percent from the ones recorded 
t the time the birds were dissected, served as a check 
n the accuracy of the wet (or dry) weights of the 
ssues. 
The samples were exposed to temperatures of 
increasing intensity, then ashed in a muffle furnace at 
550° C. for 12-72 hours, the length of time depending 
on the nature of the body part. Early phases of the 
ashing procedure were accelerated by adding distilled 
concentrated sulfuric acid to the samples. Concentra- 
tions of major elements in the ash were determined 
by flame photometric (calcium, magnesium, potassium, 
and sodium) and colorimetric (phosphorus) proced- 
ures. Analyses for trace elements were accomplished 
by atomic absorption (zinc) and emission spectro- 
graphy (aluminum, barium, boron, cobalt, chromium, 
copper, iron, lead, manganese, molybdenum, nickel, 
silver, strontium, tin, titanium, vanadium, and _zir- 
conium). The ashing and analytical procedures were 
based on techniques developed by Peggy L. Stewart 
and Isabel H. Tipton (unpublished data) for analyzing 
human food (used for fat, feathers, muscles, and 
internal organs), feces (used for bones and feet), and 
urine (used for blood). 
Care was taken throughout all phases of the dis- 
secting, ashing, and analytical procedures to prevent 
contamination of the samples. Dissecting instruments 
were thoroughly washed and then rinsed in doubly 
distilled water before opening each bird; new scalpel 
blades were also used with each bird. Except when 
the dissecting instruments were used, the body parts 
were never allowed to touch metal. The samples were 
always stored in polyethylene containers, and fused 
silica dishes that had highly glazed surfaces were used 
to hold the samples during ashing procedures. 
FINDINGS AND DISCUSSION 
Validity of the Data 
It should be emphasized that, as already mentioned, 
the analyses were conducted on pooled samples; the 
larger tissues were pooled according to geographical 
region and age of the birds, the smaller ones by region 
only. While this procedure has obvious limitations, the 
values obtained can be accepted with reasonable confi- 
dence. Theoretically, the concentrations of elements 
obtained for the pooled samples should approximate 
mean concentrations one would get if the tissues were 
analyzed individually. The consistency of many of the 
concentrations in comparable body parts—among birds 
of the three age groups and from the three regions — 
adds further confidence to the validity of the data (see 
tables ). 
However, a word of caution is in order. In biological 
material, mean concentrations of chemical elements, as 
well as means of percent ash of wet (or dry) weights, 
may be skewed toward high values (Tipton, et al. 
1963:97). For this reason, Tipton, et al. (1963:100) 
