Nebraska Bird Review 
15 
dred percent of nestling's defecated 
each day they were handled after 
day eight. 
A stepwise regression was used to 
pick from 35 variables those which 
would be suitable for calculating 
nestling age. The resulting equation 
using regression coefficients was: 
Age (in days) = -4.67 -|- .32 Tarsus 
length -j- .11 Total length .11 
Spinal tract feather length (intra- 
scapular region) -|- .16 Femoral 
tract feather length (mid-portion). 
Most predictions of age will be 
within one day of the correct age. 
Two of the characteristics selected 
as the best for calculating age were 
the same as in Redwings. 
LITERATURE CITED 
BANKS, R. C. 1959. Development of 
nestling White-crowned Sparrows 
in central coastal California. Con¬ 
dor, 61: 96-109. 
BURNS, F. L. 1921. Comparative 
periods of nestling life of some 
North American nidicolae. Wilson 
Bull., 33: 4-15. 
DAWSON, W. R., and F.C. EVANS. 
1957. Relation of growth and de¬ 
velopment to temperature regula¬ 
tion in nestling Field and Chip¬ 
ping Sparrows. Physiol. Zook, 30: 
315-327. 
- 1960. Relation of growth and 
development to temperature regu¬ 
lation in nestling Vesper Sparrows. 
Condor, 62: 329-340. 
FOSTER, M. S. 1967. Pterolography 
and age determination in the 
Orange-crowned Warbler. Condor, 
69: 1-12. 
HOLCOMB, L. C. 1968. Growth of 
nestling Goldfinches compared to 
adult size and differential develop¬ 
ment rate of structures in relation 
to their function. Nebraska Bird 
Review, 36: 22-32. 
HOLCOMB, L. C. (unpub. ). Breed¬ 
ing biology of the American Gold¬ 
finch in Ohio. Bird-Banding (in 
press). 
HOLCOMB, L. C., and G. TWIEST. 
(unpub. a). Red-winged Blackbird 
clutch size, egg parameters and 
nesting success. MS. 
(unpub. b). Growth and calcula¬ 
tion of age for Red-winged Black¬ 
bird nestlings. M.S. 
HORWICH, R. H. 1966. Feather de¬ 
velopment as a means of aging 
young Mockingbirds (Mimus poly- 
glottos) . Bird-Banding, 37: 257- 
267. 
LACK, D., and E. T. SILVA. 1948. 
The weight of nestling Robins. 
Ibis, 91: 64-78. 
MAHER, W. J. 1964. Growth rate 
and development of endothermy in 
the Snow Bunting {Plectrophenax 
nivalis) and Lapland Longspur 
(Calcarius lapponicus) at Barrow, 
Alaska. Ecology, 45: 520-528. 
WALKINSHAW, L. H. 1938. Life 
history studies of the eastern Gold¬ 
finch, Part I. Jack-Pine Warbler, 
16: 3-11 and 14-15. 
-1939. Life history studies of the 
eastern Goldfinch, Part 2. Jack- 
Pine Warbler, 17: 3-12. 
WETHERBEE, D. K. 1957. Natal 
plumages and downy pteryloses of 
passerine birds of North America. 
Bull., Amer. Mus. Natur. 
History, 113: 343-436. 
WILLSON, M. F. 1966. Breeding 
ecology of the Yellow-headed 
Blackbird. Ecol. Monogr., 36: 51- 
77. 
Department of Biology, Creighton 
University, Omaha, Nehr. 68131 
1968 FALL FIELD DAY 
The 1968 Fall Field Day was held 
in Lincoln October 13, at the Chet 
Agar Nature Center and Pawnee 
Lake. It was a warm, partly cloudy, 
day. Approximately twenty five peo¬ 
ple attended, and they reported a 
total of 58 species. 
Pied-billed Grebe, Double-crested 
Cormorant, Great Blue and Black- 
crowned Night Herons, Mallard, 
