Cowbird, brown-headed, Molothrus ater

Phalacrocorax spp., 266, 267,436 Cotumix, Coturnix coturnix, 34, 133, 835 Cowbird, brown-headed, Molothrus ater, 34, 123, 287,446... 

Brown-headed cowbirds Molothrus ater) can discriminate ethyl butyrate and 5-limonene, as evidenced by cardiac conditioning. Furthermore, they discriminate among concentrations of ethyl butyrate. To discriminate the two odorants, vapor saturation must be at least 0.6%. This suggests that for ethyl butyrate the discrimination sensitivity is at least 1.9 x 10 molecules/ml, or 0.76 ppm (Clark and Mason, 1989). 

Brown-headed cowbirds, Molothrus ater, and red-winged blackbirds, A. phoeniceus, removed 95-98% less rice seeds sown in flight pens if the seeds had been treated with methiocarb. The effect was the same whether 100% or only 50% of the seeds had been treated. This shows that an entire prey population can be protected even if only a portion is unpalatable. Such automimicry may permit partial treatment of crops with repellents, which would be effective, environmentally sound, and economical (Avery, 1989). Batesian mimicry offers advantages over food aversion learning (Reidinger and Mason, 1983). 

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