Reproductive behavior

Sexual dichromatism is uncommon in piciforms. Most often, males and females look alike, probably because birds that maintain a year-round monogamous pair bond do not require elaborate courtship displays. In woodpeckers, though males and females often have different plumages, the differences between the sexes tend to be subtle, involving the color of nape patches

Chestnut-mandibled toucans (Ramphastos swainsonii) in Panama. (Photo by Art Wolfe. Photo Researchers, Inc. Reproduced by permission.)

or the presence or absence of "moustaches." Neotropical barbets are the exception to the rule of uniform plumage for this group; all barbet species show marked differences between males and females with regard to plumage color and/or pattern.

Most piciform birds are cavity-nesters; even the hon-eyguides, all of which are nest parasites, lay their eggs in the nests of other hole-nesting species such as barbets and woodpeckers. The type of cavity used varies among families. Some species of jacamars and puffbirds dig out nest sites in rotten trees where termites have nested. Other species in these two families excavate their nesting burrows in soil, often along riverbanks. Barbets and woodpeckers use their strong, sharp beaks to hammer out nest cavities in rotting trees, and the largest toucan species occupy natural tree cavities. The smaller toucan species often drive woodpeckers away from just-excavated holes, then use their powerful beaks to enlarge the nest opening.

Almost all members of this group lay white eggs. Unpig-mented eggs are typical of cavity-nesting birds—with the nest hidden from predators, there is no need for the eggs to be camouflaged.

Pileated woodpecker (Dryocopus pileatus) young in the nest. (Photo by Joe McDonald. Bruce Coleman Inc. Reproduced by permission.)

Helping at the nest, an uncommon bird behavior, is often seen in woodpeckers, and is also known in some species of toucans.

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