Voi. xvn 
1899 J 
Owen, A Family of Nestlings. 
22 1 
A FAMILY OF NESTLINGS. 
BY D. E. OWEN. 
Observers who have watched the growth of nestlings, from the 
hatching of the eggs to the abandonment of the nest by the 
young birds, often have been struck by the rapidity of the devel- 
opment witnessed ; but, owing to the difficulty of obtaining quan- 
titative data, exact information on this branch of bird study is 
meagre. In order to formulate an accurate record of the growth 
of a nestling, it is necessary to weigh the bird, at stated intervals, 
for as long a period as possible. This operation, it is needless to 
say, bristles with embarrassments. The unfavorable conditions 
for careful manipulation of the balance that obtain in field and 
thicket, especially during wet or windy weather, taken in conjunc- 
tion with the inaccessibility of many nests and the inconvenient 
situation of most, render the study of ornithology, along such 
experimental lines, a pursuit characterized by trial and disappoint- 
ment. Occasionally, however, a peculiarly favorable opportunity 
— such as the one about to be described — enables the observer 
to obtain facts of sufficient value to justify the labor involved in 
the research. Q 
Early in June, 1898, the writer of these notes built a small 
camp at Saco Ferry, Maine. The building was placed over an 
old cellar, a portion of which only was utilized, the remainder, 
which lay in the rear of the camp, being left uncovered as a sort 
of sunken back-yard. Into this grass-grown excavation the refuse 
building materials had been thrown, and it was while we were 
clearing away the rubbish that a nest of a Song Sparrow {Melos- 
■piza fasciata) was discovered, snugly ensconced beneath a half- 
buried brick that protruded from the sloping wall of the ruined 
cellar. The nest contained several eggs which were increased in 
a few days to the full complement of five. On the 14th of July, 
four of the eggs hatched, and at our morning call the next day, we 
were confronted by five gaping red mouths, accentuated by big 
black eyes, and barely supported by five feverish, naked little 
bodies ; and when, by means of a teaspoon, properly warmed, we 
had removed one of the birds for more minute inspection, we 
were alternately amused and stricken with concern, as the flabby 
