Porcupines: The Animal Answer Guide

Chapter 3. Porcupine Colors

51 Chapter 3 Porcupine Colors What color are porcupine quills? The quills of the larger porcupines—the Old World Hystrix and Atherurus, and the New World Erethizon (eastern subspecies), Coendou prehensilis, and C. bicolor—are black and white or brown and white, though individual animals with all-black and almost all-white quills are also found. In the western subspecies of the North American porcupine, the animals look yellowishbrown . The yellow-brown color comes from the guard hairs, which are longer than the quills and give the animals a deceptively furry appearance. Among the small porcupines of South America, quills are typically yellowish or whitish with brown tips or brown bands, or all black. The details of quill color patterns are important when distinguishing related species. For instance, Robert Voss and Maria da Silva, in describing two new porcupine species from South America, paid special attention to the color patterns of the quills. They compared their new species, Coendou ichillus and C. roosmalenorum, with two related, previously described species, C. pruinosus , and C. vestitus. Voss and da Silva noted that all four species have two kinds of quills: (1) the normal body quills, with sharp, barbed tips; and (2) bristle quills— longer, thinner, barbless quills that end in a thin filament. They found that S. vestitus could be differentiated from the other three species on the basis of color patterns of bristle quills, as shown in the table. The remaining three species could be differentiated on the basis of body quill color patterns . In this case, quill types and color patterns alone distinguish all four species, but the authors went on to describe and compare nine other distinguishing characters. 52 Porcupines: The Animal Answer Guide Clearly, this kind of close, careful analysis will not be always possible in the field, where the animal is in a tree and the observer on the ground. But there is one South American porcupine that it may be possible to identify in the field: the stump-tailed porcupine. Unlike all other South American porcupines, its quills have white bases tipped with brown or reddish bands. The fact is noted in its Latin name, Coendou rufescens, where rufescens means “reddish.” This porcupine stands out among South American porcupines in general. In addition, the animal’s tail is proportionately the shortest among South American porcupines, measuring only 40% of head + body length. Is there a reason for coat color patterns in porcupines? Coat colors in animals can serve a number of important functions. Vulnerable animals like snowshoe hares have coat colors that blend with the background, to make them less visible to predators. The snowshoe hare, which is brown during the warm months, turns white in the winter, along with the changing background. Predators may likewise have coats that blend with the background, the better to ambush their prey. On the other hand, well-defended animals like coral snakes and skunks carry coat colors that make them more conspicuous and intimidating to potential predators. Coat colors may also act as signals within a species. Thus, the bright colors of male scarlet tanagers attract females during the breeding season but fade to yellow-dun when out of season. In many primates such as baboons, macaques, and chimpanzees, females signal receptivity by pink swelling of the genital region. Most porcupines are well-defended animals, potentially dangerous to their predators. Their coat colors do not usually blend with the surroundings , as does the fur of the snowshoe hare or the feathers of a ruffed grouse. Identification of four South American porcupine species, genus Coendou, from quill color patterns Species Bristle quills Body quills C. vestitus Bicolored Long, dark tips C. pruinosus Tricolored Some head quills tricolored Long, pale tips Short, dark tips C. ichillus Tricolored Some head quills tricolored Long, pale tips Long, dark tips C. roosmalenorum Tricolored All quills bicolored Long, pale tips Very short, dark tips 53 Porcupine Colors To the contrary, typical porcupine coat colors, like the coat colors of skunks or red efts, stand out against the background and provide a warning to potential predators. Porcupines are active primarily at night, so the warning signal must also be visible at night. In most porcupines, the signal is a black and white contrast. In many South American porcupines, it is a dark brown–pale yellow contrast. The North American porcupine shows a white chevron on its back that continues onto the tail and...