V °i8^ VI ] Owen, A Family of Nestlings. 22J 



We were, in a measure, prepared for noteworthy results, but 

 we were not prepared for the rapidity of growth that the table 

 records. The family whose members increase in average weight 

 48% in twenty-four hours is a thriving one indeed; yet this is 

 the rate of increase of the nestlings for July 16-17. The rate 

 falls off after the latter date, becoming successively, 25%, 20%, 

 13%, and, finally, 7% in a day. Most interesting and suggestive 

 are the figures showing the growth of the marked bird. It is a 

 common impression that the runt of the brood has a bitter 

 struggle for existence, being, by reason of inferior strength, 

 largely at the mercy of its greedy fellows and crowded out of 

 much-needed food in consequence. The results above noted 

 would seem to imply that in well-regulated feathered households, 

 at least, the doctrine of the survival of the fittest is warmly tem- 

 pered by justice and mercy. At all events, the smallest Song 

 Sparrow grew phenomenally. He picked up 55% in weight the 

 second day of his life and save on a single day his increase never 

 failed of being from 6% to 20% above the average ! Beginning 

 existence as the smallest of the lot and weighing, the second day, 

 1.3 grams less than the average, the marked bird grew, in a week, 

 to weigh only half a gram, or about -^ of an ounce less than the 

 average, a record which bears testimony to abundant nourish- 

 ment and a good digestion. 



The rapid increase in weight of the nestlings needs no theoriz- 

 ing to account for it. The devotion of parent birds to their 

 young and their industry in providing food are proverbial ; but no 

 one who has neglected to sit watch in hand, within range of a 

 nest of five importunate, half-fledged youngsters can formulate an 

 adequate conception of the fidelity with which birds discharge 

 their parental duties. We made it a point to watch the nest of 

 Song Sparrows in the old cellar from the camp window, whenever, 

 through the day, it chanced to be convenient. With watch or 

 clock before us and writing materials at hand, we sat at intervals 

 of from fifteen minutes to an hour and a quarter at a time, accu- 

 rately noting the visits of the parent birds. It was absorbing and 

 exacting work. The old birds never flew directly to the nest, but 

 approached it by stealthy stages, alighting now on a rock, now on 

 the camp, again on a small bush. A rapid scrutiny of the cellar, 



