Practice question

Red, tubular, unscented flowers are associated with ornithophily, the bird-pollination syndrome. Many flower-visiting birds have strong color vision, including sensitivity to red, but rely less on odor than nocturnal moths or many insects. A tubular corolla can match a bird’s bill and position pollen on the head or body as nectar is reached. Such flowers often provide abundant, dilute nectar and are robust enough to withstand bird contact. Pollination syndromes are probabilistic trait combinations, not rigid rules: bees can visit red flowers, birds can visit nonred flowers, and actual pollinators must be established by observations and pollen-transfer experiments. Bee-pollinated flowers commonly show blue, violet, yellow, ultraviolet guides, and accessible landing surfaces. Moth-pollinated flowers are often pale, strongly scented at night, and nectar-rich, while beetle-pollinated flowers tend to be open, sturdy, and strongly scented. The combined visual, morphological, and olfactory traits therefore most strongly predict bird-mediated pollen transfer. Floral rewards reinforce repeated, efficient visits.