THRUSHES, SOLITAIRES, BLUEBIRDS: ROBIN 567 
into flocks. Meanwhile the adults go off by themselves and remain 
sequestered until completion of their annual molt. Then, in late 
September, the Robins, without regard to sex or age, gather into 
mixed flocks and, for the most part, spend the winter in such gatherings’ 7 
(1924, p. 607). One such gathering recorded by Mr. Ernest D. Cla- 
baugh, at Berkeley, California, totaled about seven hundred birds, 
roosting at night in two places under observation (1928, p. 126). 
When the Western Robin deserts the mountains to nest in town it 
now finds itself face to face with the aggressive English Sparrow. A 
remarkable case of aggression is given by Mr. Jensen in the Auk, 
under date of July 1, 1925. He says: “During the latter half of May, 
1925, a pair of Robins built a nest in a locust tree in front of my house. 
Four eggs were laid and in due season four young appeared. The 
parent birds have since been busy feeding the young. A pair of 
English Sparrows discovered the Robin’s nest and saw the process of 
feeding. Now for about two weeks the Sparrows have been watching 
the Robins closely, and whenever one of these fly down on the lawn 
in search of food for the young, the Sparrows will follow it. As soon 
as the Robin captures a grasshopper or a worm and flies to the nest, 
the Sparrow will follow and alight on the rim opposite the Robin. 
As soon as the Robin has placed the food in the open bill of one of the 
youngsters, one of the Sparrows reaches over and pulls the food out 
and flies away to a quiet place to devour it. 
“The young Robins do not seem to suffer from lack of food, so I 
imagine the parents may have to work harder to offset the robberies of 
the Sparrows” (1925c, p. 591). 
An interesting case of nestling Western Robins being fed by a 
Russet-backed Thrush is recorded by Stanley G. Jewett, under the 
caption, “Assistant Parentage among Birds.” Twelve times in four 
hours, the Thrush was seen feeding its neighbor’s nestlings (1928, 
p. 128). One wonders if it had lost its own little brood. 
In the Southeast, where it has sometimes been difficult to stop 
the market trade in Robins and other small birds, a technical character 
once saved the day. It was in Washington, and a member of the 
Biological Survey was called down to the famous “Center Market” to 
examine hanging bundles of small plucked birds, which the dealer 
was sure no one could identify. In his ignorance, however, he had 
left on the legs, and one look of the professional at the “tarsus” 
settled the question—it was “booted”—the outstanding character of 
the family of Thrushes to which the Robin belongs, and common to 
no other birds of similar size, the Robin, moreover, the only member of 
the family used for market purposes. The dealer was convicted and 
fined, and the Judge in pronouncing his sentence remarked that he 
