Geoscience Reference
In-Depth Information
Bright coloration in birds allows them to blend in with the brightly colored
flowers and fruit that have evolved coloration to attract pollinators. It also helps
with species recognition when birds seek mates in the dense foliage of a vast forest.
Various beak sizes allow birds to utilize different food sources, such as fruits, nuts,
insects, and even crabs.
Yet another adaptation to arboreal life is the development of limbs or skin flaps
that aid in gliding through the forest. This is particularly varied in Borneo. Here glid-
ing squirrels, colugos, snakes, lizards, and frogs travel throughout the forest canopy
seldom visiting the forest floor. Loose skin along the body and limbs spreads out to
form a broad surface, aiding in long-distance gliding through the forest.
Loud vocalization in birds and primates is an adaptation for communicating
within the dense forest layers. The howler monkey of the Neotropical Rainforest
and siamang in Asia are known for their long-distance calls and the variety of vocal-
ization within and outside a group. These primates are most vocal at dusk and dawn.
The shrieks of Scarlet Macaws can be heard far below and away from the flock.
Some tropical animals exhibit warning coloration; this is also called aposematic
coloration. Warning coloration makes a dangerous, poisonous, or foul-tasting ani-
mal particularly conspicuous and recognizable to a predator. Several animals ex-
hibit this coloration, such as the yellow and black stripes of bees and wasps, orange
and black coloration in beetles, and the bright red or yellow colors of many poison-
ous frogs and snakes. Warning coloration alerts potential predators that the species
is dangerous or toxic and should not be eaten. Would-be predators learn to avoid
organisms with warning coloration.
The survival of any tropical animal depends on its ability to find food, shelter,
water, and mates, and to avoid predation. One of the adaptive strategies found in
tropical animals is mimicry. Mimicry is a form of biological interaction in which
species resemble the appearance or behavior of other species. Several types of mim-
icry are common. Similarity in appearance, or so-called parallel mimicry, signals
or warns potential predators that an animal is unpalatable or poisonous by having
several different species adopting the same warning colors. The use of similar colo-
ration, particularly reds, oranges, and yellows, is found among beetles, butterflies,
and other insects, and serves to warn potential predators. Batesian mimicry is the
condition when a nonharmful species mimics the appearance of a harmful species
within the same family to avoid predation. This strategy is common among tropi-
cal animals. The Monarch butterfly is mimicked by the nonpoisonous Viceroy but-
terfly, a classic example of Batesian mimicry. This type of mimicry is also used by
some less harmful snakes so that they look highly poisonous and predators will
leave them alone. Colors and patterns of the harmless false coral snake and the
mildly poisonous coral snake are similar to those of the very poisonous coral snake.
Other organisms display predatory mimicry and resemble their prey, increasing
their chances of a more successful marauding venture. Plants also possess mimicry
strategies, their flowers often mimicking the scent or appearance of a potential pol-
linator's mate or, in the case of carnivorous plants, their prey.
