eaten DSU. B OEN). B2Us EG Ch TobeN 23 
Bluebirds 
By Anna C. Ames 
1. EASTERN BLUEBIRD (Sialia sialis) 
THE EASTERN BLUEBIRD, state bird of Missouri and New York, is 
regarded as the symbol of happiness. They are birds of open farming 
country and of many suburban communities. The bird’s beautiful blue 
eolor, warbling song, and gentle ways make it a favorite. 
The male has a reddish-brown breast; the female is duller. The young 
have the spotted breasts of the thrush family, to which they belong, 
and are blue only on wings and tail. The Bluebird appears round-shouldered 
when perching. It habitually perches on posts or wires, dropping to the 
ground only long enough to snatch food. 
The earliest birds in spring are ordinarily males. Sometimes a flock 
of males may be seen, but many birds are paired when they arrive in the 
North. There are many combats among rival males, and sometimes two 
females will contend fiercely for the favor of a particular male. 
The five to six pale blue eggs are always placed in a cavity of a fence 
post, telephone pole, etc., or in a birdhouse. The birds do not excavate their 
own nests, but find woodpecker holes and other cavities. The female 
does most of the nest building, with grass rootlets, fine twigs, and 
feathers. ‘Often the nest is near a human dwelling. 
Both parents are devoted in incubation and care of the young, which 
remain in the nest from 15 to 19 days after hatching. Usually when the 
first brood is out of the nest, the male takes charge of the young while 
the female prepares a nest for the next brood. Sometimes there is even a 
third brood. By August, the last brood is grown and migration begins. 
Lowell fittingly described the song of the Bluebirds when he spoke of, 
“the Bluebird bearing its light load of song from post to post.” The 
song is a gentle warble, nothing more. Occasionally, as the nesting season 
advances, an enthusiastic male will leave a treetop and flutter up into 
the air for a hundred feet or so, and then sail down again to a treetop, 
singing all the way. Although regarded as gentle, the Bluebird can be 
quite aggressive when defending his nest. 
Eastern Bluebirds breed in North America east of the Rockies, from 
southern Canada and Newfoundland to southern Florida, and along the 
Gulf coast to southern and west-central Texas. They winter chiefly 
south of the Ohio River and the Middle Atlantic states. Those that pass 
the winter in New England possibly have nested farther north. 
Flocks of Bluebirds go south in October. They return to the northern 
United States, on the average, about the middle of March. Occasionally 
the birds come north too early and perish in a spring blizzard. Bluebirds 
seem rather susceptible to sudden changes of weather in winter, and 
hard freezes in the south have at times resulted in the death of many. 
As a beneficial bird, the Bluebird has a record equaled by few other 
species. A large proportion, 68%, of its diet consists of insects. Beetles 
consitute about 21% of its food, grasshoppers 22%, caterpillars 14%, 
and other insects 9%, while spiders and myriapods comprise the remainder 
of its anmial diet. During August and September about 53% of the diet 
is grasshoppers. The fruit-eating period of the Bluebird is not in summer 
when cultivated fruit is on the trees, but from October to February, when 
three-fourths of its fruit eating is done. Thus, fruit tides Bluebirds over 
until insects are again abundant, and takes the place of seeds eaten by 
other birds at this season. Seven-tenths of the diet is animal matter. 
