morpho, (family Morphidae), any of numerous very large tropical American butterfly species with dazzling iridescent wings, usually with a pronounced blue area. With wingspans that can reach 20 cm (8 inches), morphos are among the largest and most iridescent Central and South American butterflies. Their range extends from Mexico through Central America to Venezuela and Trinidad and to Colombia, Ecuador, and Peru and includes forests from sea level to 1,400 metres (4,600 feet). Morphos soar effortlessly along roads, trails, and streams. Their flyways seem to function like roads for most individuals in a given population.

While not in flight, adult morphos tend to stay hidden on the ground with their wings closed, exposing only the drab undersides in an effort to foil birds like jacamars and flycatchers, which prey upon them. The bright blue coloration that distinguishes morphos is primarily due to microscopic ridges on the butterflies’ wing scales that scatter and reflect light. At least two types of light-reflecting wing scales—ground scales and glass scales—have been described in morphos. Ground scales absorb longer wavelengths of light, and, hence, light reflected from the wing is blue to purple in color. Some species of morphos have a layer of transparent glass scales covering the ground scales. This layer of glass scales acts like a diffraction grating (a component of optical devices), increasing the angle over which light reflected from the ground scales is spread. Morphos’ brightness and the increased angle of reflected light may facilitate communication over long distances. Females generally are duller-colored than males.

Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
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Except for some morphos that rarely descend from the treetops, most adults feed on fallen fruit as well as mud and carrion. The females are most active at midday, searching for the right plants on which to lay their dome-shaped eggs. The larvae eat several species of leguminous plants, and each egg is laid singly on the underside of a leaf upon which the hatchlings will feed. The caterpillars live in a communal web; they are mottled red and yellow, and their black heads are covered with irritating hairs. After attaining a third-instar length of 9 cm (3.5 inches), the caterpillar creates a light green oval chrysalis from which it will emerge as a butterfly. The life cycle from egg to adult is 115 days. Morphos are bred commercially for decorative use in items such as display boxes, jewelry, lampshades, and inlays.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Melissa Petruzzello.
little wood satyr
little wood satyr
Also called:
brown

satyr butterfly, (subfamily Satyrinae), any of a group of delicate butterflies in the family Nymphalidae (order Lepidoptera) that are abundant during summer months in the woods and grasslands of the United States and Europe. The adults are dull brown or grey, while the larvae possess small, forked tail-like appendages on their abdomens. Adult butterflies have brown wings with a span of 5 to 6 cm (2 to 2.4 inches) and conspicuous circular markings on them. These false “eyes” on the wings may serve to frighten or distract predatory birds.

Some of the best-known satyrs are pearly-eye butterflies. Southern pearly-eyes (Enodia portlandia) have dark eyespots near the margins of their forewings and hind wings. They are found primarily in the southeastern region of the United States, with their range extending west to the eastern edge of Texas. They inhabit damp, wooded areas and feed on decaying fruit and animal flesh as well as on sap. Southern pearly-eye larvae occur on the bamboo plant Arundinaria tecta, which also serves as host to the larvae of creole pearly-eyes (E. creola) and several species of skippers (e.g., Carolina roadside-skippers, Amblyscirtes carolina, in the order Lepidoptera). Northern pearly-eyes (E. anthedon) are similar in appearance to their southern counterparts and are found mainly in the northeastern region of the United States and in Canada, from central Saskatchewan to Nova Scotia.

Mute swan with cygnet. (birds)
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This article was most recently revised and updated by Amy Tikkanen.

brush-footed butterfly

insect
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Also known as: Nymphalidae, four-footed butterfly
mourning cloak butterfly
mourning cloak butterfly
Also called:
four-footed butterfly

brush-footed butterfly, (family Nymphalidae), any of a group of butterflies (order Lepidoptera) that are named for their characteristically reduced forelegs, which are frequently hairy and resemble brushes. The insects’ alternative name derives from the fact that there are only four functional, or walking, legs.

Most species have a wingspan of 35–90 mm (1.5–3.5 inches) and white, yellow, or brown wings with contrasting markings and undersurfaces often with duller, more protective coloration. Common nymphalids include the anglewings, mourning cloaks, and thistles (subfamily Nymphalinae); heliconians and fritillaries (subfamily Heliconinnae); and viceroy butterflies (subfamily Limenitidinae). Most nymphalid larvae are brightly coloured and have knobby projections (tubercules), horns, and branching spines. The naked pupae, or chrysalids, hang head downward.

Mute swan with cygnet. (birds)
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Adult anglewings show seasonal dimorphism, with the autumnal generation being hairy and lighter-coloured. Some also exhibit sexual dimorphism, with the female being less conspicuous than the male. Most species have a silvery spot on the undersurface of each hindwing. The spiny larvae feed on elm and birch trees, hops, and nettles.

The buckeye butterfly (Junonia coenia), a member of the Nymphalinae subfamily, is distinguished by two eyespots on the upper side of each of its forewings and hindwings and by two orange cell bars on the upper sides of the anterior portion of the forewings. Its body colour is brown. Its range extends from southern Canada and the United States to southern Mexico. Adults feed primarily on the nectar of flowers, such as those of chicory, knapweed, dogbane, and aster.

The mourning cloak (Nymphalis antiopa), known as the Camberwell beauty in England, overwinter as adults. The larvae, often known as spiny elm caterpillars, are gregarious in habit and feed principally on elm, willow, and poplar foliage.

The thistle butterfly (Vanessa) is named for its principal larval host plant. Some species, such as the painted lady (V. cardui), migrate during adulthood, traveling in large groups.

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The name fritillary is applied to several nymphalid genera. The large fritillaries, or silverspots, belong to the genus Speyeria and usually have silver markings on the undersides of the wings. Many of the smaller fritillaries are members of the genus Boloria. Many fritillary larvae are nocturnal and feed on violet leaves.

The viceroy (Basilarchia archippus or Limenitis archippus) is known for its mimetic relationship with the monarch butterfly (Danaus plexippus). The two species resemble one another in their coloration, and both are distasteful to predators. Viceroy larvae feed on willow, aspen, and poplar foliage and retain in their bodies toxic compounds from it; those species of plants produce salicylic acid, a bitter-tasting compound best known for its use in the preparation of aspirin and other pharmaceutical products. (The monarch acquires its bad taste as a caterpillar, when it feeds on milkweeds, which produce toxic compounds known as cardenolides that are stored in the insect’s body.) Through their shared coloration, it is believed that the viceroy and monarch derive protection from predatory attack. The viceroy can be distinguished from the monarch by its smaller size and by a black transverse band on each hindwing.

This article was most recently revised and updated by Richard Pallardy.