Diet
Major Food Items
In Texas, wide variety of seeds, including bristle grass (Setaria spp.), doveweed (Croton texensis), sandbur (Cenchrus spp.), panicum (Panicum spp.), sorghum, and pigweed (Chenopodium album), and fruits of cactus (Opuntia spp.) and nightshade (Solanum spp.), as well as grasshoppers, caterpillars (Lepidoptera), beetles (Coleoptera), stinkbugs (Pentatomidae), and cicadas (Cicadidae). McAtee (McAtee 1908a) suggested that Pyrrhuloxia prefers grasshoppers to caterpillars to beetles and eats much less fruit than Northern Cardinal does.
In s. Arizona, prefers sunflower (Helianthus spp.) seeds and "peanut butter suet" at feeders, although also eats other seeds and household scraps (Anderson 1968).
Quantitative Analysis
From McAtee 1908a . In Aug and Sep, stomachs collected in Texas contained 71.2% vegetable matter and 28.8% animal matter. Most of the vegetable matter (53.1% of total) was "grass seeds," primarily yellow foxtail (Chaetecholoa glauca) and bur grass (Cenchrus tribuloides), which provide 43.6% of total food. Other weed seeds included crabgrass (Syntherisma spp.), joint grass (Paspalum spp.), and wire grass (Eleusine indica). Seeds of a spurge (Croton sp.) made up 9.8% of diet. Of the remaining seeds, only sorghum made measurable contribution (2.0%). Animal matter made up of beetles (4.7%) (mainly weevils [3.4%], including cotton boll weevil [Anthononus grandis]), caterpillars (10.3%, including cotton worm [Alabama argillacea]), and cotton cutworm (Prodenia ornithogalli). Grasshoppers made up 11.5% and true bugs (Hemiptera) 1.5%.
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