CASSIN'S KINGBIRD 73 



ish brown; there is no orange-red crown patch; the paler markings 

 on the wings are tinged with buff, and the outer primaries are not 

 attenuated; the tail feathers are somewhat shorter than in the adult, 

 and are narrowly tipped with brown. This plumage is worn through 

 the summer, until an apparently complete postjuvenal molt, mainly 

 in September, produces a first winter plumage, like that of the adult, 

 but slightly paler and still lacking the crown patch. In this first 

 winter plumage the young male acquires the attenuated outer pri- 

 maries as in the adult; adult males have four or five of the outer 

 primaries sharply attenuated; in adult females these feathers are 

 only bluntly pointed, if at all so. In the first winter tail the feathers 

 are tipped with yellowish gray, or whitish, and more broadly than 

 in the younger bird. Apparently there is a partial prenuptial molt 

 early in spring, at which the orange-red crown patch is acquired. 

 Adults apparently molt at the same times and in the same manner as 

 the young birds; June and July adults show considerable wear. 



Food. — Living in much of the territory occupied by the Arkansas 

 kingbird and foraging in much the same manner, the food of Cassin's 

 kingbird is almost identical with that of the better-known species. 

 Professor Beal (1912) examined only 40 stomachs of Cassin's king- 

 bird, in which the food was "found to be composed of 78.57 per 

 cent of animal matter to 21.43 of vegetable." Of the animal food — 



beetles of all kinds amount to 14.91 per cent of the food. Of these, about 

 1 per cent are of species that are more or less useful (Carabidae). • * * 

 Hymenoptera amount to 21.61 per cent and consist for the most part of wild 

 bees and wasps. No honeybees were found, but several predaceous or parasitic 

 species were identified. * * * Lepidoptera, i. e., moths and caterpillars, 

 amount to 18.21 per cent of the food, which is a high percentage for a flycatcher ; 

 for while moths may be caught on the wing, caterpillars must be picked from 

 the surface on which they crawl, unless they let themselves down from a 

 tree by a thread and so hang in mid-air. * * * Orthoptera (grasshoppers 

 and crickets) are apparently eaten rather irregularly, but as nearly every 

 month in which they appeared at all showed a goodly quantity, they would 

 seem to be a favorite food, and it is probable that a greater number of stomachs 

 would give a more regular showing. In January they amount to 47.50 per 

 cent in 4 stomachs, while the 1 stomach taken in February shows none at 

 all. * ♦ * The total for the year Is 14.67." 



Small percentages of Hemiptera (bugs), Diptera (flies), a few 

 dragonflies, and some spiders make up the balance of the animal 

 food, 9.17 percent. 



Of the vegetable food. Professor Beal (1912) says: "Although 

 Cassin's kingbird eats more vegetable food than any other flycatcher, 

 there is very little variety to it. Grapes, apparently of cultivated 

 varieties, were found m 9 stomachs, olives in 2, elderberries in 1, 

 blueberries (Vaccinium) in 1, and pulp not further identified in 4. 

 With the exception of some grapes found in 1 of the March stomachs. 



