. Essgewohnheiten der Stenpfschnäbel . 84 ERNÄHRUNGSGEWOHNHEITEN DER GEOSBEAKS. Mehr als 13 Mal so viel wie die alten Vögel nehmen. So weit scheint eine Dis-Crepancy darauf hinzuweisen, dass es zwischen jungen und jungen Vögeln einen großen Unterschied in der Notwendigkeit für dieses Material gibt. Jung. Unter den untersuchten Blauen Stelzen sind 13 Jungtiere, die im Juli und August in Kansas gesammelt wurden. Acht von ihnen sind Nestlinge, und 5sind junge gerade aus den Nestern, aber immer noch von ihren Eltern gefüttert.der Prozentsatz der Tiernahrung für die 13 Jungvögel ist 99.08; ofvegetable, 0.92. Heuschrecken machen 74.1 Prozent der Nahrung aus. Unter ihnen sind enthalten
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. Food habits of the grosbeaks . 84 FOOD HABITS OF THE GEOSBEAKS. more than 13 times as much as the old birds take. So wide a dis-crepancy would seem to indicate that there is great difference betweenold and young birds in the need for this material. Young. Among the blue grosbeaks examined are 13 young collected inKansas in July and August. Eight of these are nestlings, and 5are young just out of the nests, but still being fed by their parents.The percentage of animal food for the 13 young birds is 99.08; ofvegetable, 0.92. Grasshoppers constitute 74.1 percent of the food. Among themare included the lesser migratory locust {Melanoplus atlariis) and alarge coral-winged locust {Hippiscus, fig. 40). The remains of asmany as 16 short-horned locusts were obtained from one stomach, while another contained 14. Caterpillars, among them the purslanesphinx, compose 10.7 percent of the subsistence of the nestlings, and. FiQ. 40.—Coral-wlnged locust (.Hippisous tuberculatus). (Prom Lugger, Minnesota Ex-periment Station.) snails 10 percent. The remainder of the animal food consists of aweevil, a long-horned beetle, a ground beetle, a robber fly, and theeggs of a tachina fly, which were on the purslane caterpillar. It iscurious that^so large a proportion of the beneficial insects consumedshould be in the stomachs of nestlings, but it may be that these items, which ordinarily are rarely taken, are hurriedly gathered only be-cause of the insistent demands of the hungry young. The vegetable food consists of a few unidentified vegetable fila-ments and some slight remains of blackberries in two stomachs; thiswas the only fruit eaten by any of the birds, young or old. Summary. Present data shows that the food of the blue grosbeak is 67.6 per-cent animal and 32.4 vegetable. Grain constitutes 14.25 percent of the diet, but on account of thescattered distribution of the birds, no appreciable damage is donedurin
