Pp

palm There are about 2,780 species of palms organized into about 210 genera within the palm family, Palmae. They grow in the form of trees, shrubs, and vines and occur primarily in tropical or subtropical climates, though some grow in temperate regions. By far the largest number of palms are found in tropical America (with about 500 species concentrated in Brazil alone) and tropical Asia. Most palms do not grow above elevations of 4,000 feet (1,220 meters). The ranges of most individual species are quite restricted, and many island palms are found nowhere else. Palms are usually characterized by a tall, unbranched, columnar trunk crowned by a tuft of large leaves. The leaves are firm, pleated, and fan- or feather-shaped with stout sheathing and often prickly stalks. The bases of the stalks frequently clothe the palm's trunk. The leaves may be more than 30 feet (9 meters) long. The small flowers of the palm are produced in large clusters borne on simple or branching spikes. The fruit of the palm may be dry or fleshy.

parasite An organism that lives on or within another organism, called the host, and that gains its sustenance from the host organism is known as a parasite. Parasites occur among all the major groups of living things. There are parasitic fishes for example, the lamprey, which attaches itself to other fishes and sucks their body fluids. There are many parasitic arthropods, including fleas, lice, biting flies, and mosquitoes

parous Referring to a female who has produced offspring.

parrot Parrots have excellent hearing and vision and some are renowned for their ability to mimic human speech and other sounds. The amazon parrots are perhaps the most familiar mimics, but the African gray parrot is unsurpassed as a talker. Both birds may develop extensive vocabularies, and at least some species may understand what they are saying. Parrots and certain other birds can transmit psittacosis, a potentially fatal viral disease that can infect humans. As a precaution, laws were enacted in the 1930s regulating the importation of these birds.

pearl Pearls form in mollusks, a group of shell-covered water animals that includes oysters, clams, and mussels (see Mollusks; Oyster). These mollusks line the inside of their shells with a substance called nacre. When a foreign body enters the mollusk, the animal protects itself by depositing layer after layer of smooth nacre around the irritant. This bead of nacre is called a pearl. Most mollusks are capable of producing pearls, but the common sources of commercial pearls are oysters, which produce saltwater pearls, and mussels, which produce freshwater pearls.

pelagic An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

pelican . The bird is large-bodied and short-legged and has a bill that is longer than its head with an enormous pouch of skin fastened to the lower mandible. The pouch does in fact hold more than the pelican's stomach about 3 gallons (11 liters) when full. Pelicans use the expandable pouch as a dip net: they scoop up fish through their wide-open mouths then hold the fish in the pouches long enough to squeeze out the water from the corners of their mouths. Then they swallow their catch. The pouch is not used to store fishes; they are carried in the gullet, or esophagus. The solemn-looking pelicans are among the largest of living birds. Some reach lengths of 70 inches (180 centimeters) and may weigh up to 30 pounds (14 kilograms). They flock together in colonies to rear their young, and some species set out in groups on fishing trips. They are silent creatures, emitting no sound but an occasional grunt. Pelicans belong to the family Pelecanidae.

peony With its shiny, dark green foliage and showy masses of brilliant blooms, the peony is a popular garden flower. It thrives in any soil and has been cultivated since the days of the ancient Romans. The plants, which grow to a height of 7 feet (2 meters), flower in early summer. The blossoms are 6 to 8 inches (15 to 20 centimeters) across and vary in color from white or yellow to lilac, violet, and red.

pheasant Most pheasants are long-tailed birds of open woodlands and fields. All have hoarse calls and a variety of other notes. The males of most species are strikingly colored. A male pheasant pugnacious in the breeding season has one or more leg spurs and may have fleshy ornaments on the face. Courting males sometimes fight to the death in the presence of hens, who seem utterly indifferent to the commotion.

philopatric Referring to an animal that has a tendency to return to or stay in its home area, or to return yearly to the same area to breed.

photo-trapping A method of observing hard-to-see animals by taking their pictures automatically, using remote cameras triggered when the animal interrupts an infrared light beam.

phylogenetic Referring to the closeness of evolutionary descent.

pig . As a domestic animal it is a source of a wide variety of meats, high-quality leather, durable bristles for many kinds of brushes, and hundreds of medical products. At the same time, the pig is frequently regarded as unclean and even untouchable by many people. In spite of their reputation, pigs are neither filthy nor stupid. Because their sweat glands are relatively ineffective in lowering body temperature, pigs seek relief from the heat by wallowing in mud or shallow waterholes. When provided with a clean environment sheltered from the sun, however, pigs are fastidious. Furthermore, in tests of intelligence, pigs have proved to be among the smartest of all domestic animals even more intelligent than dogs. Pigs are closely related to peccaries and distantly related to hippopotamuses. Their snouts end in a flat, rounded disk, which is used by all species but one to root for food. Their stocky, barrellike bodies weigh between 300 and 700 pounds (140 and 300 kilograms) and sometimes reach weights as great as 1,900 pounds (860 kilograms). Both males and females have tusks, which they use for defense. The tusks are sharpened as the pig chews: its upper and lower tusks rub against one another.

Pigs have a firm, thick skin covered with a usually sparse coat of stiff hairs called bristles. Pigskin is renowned for producing a high-quality leather that "breathes" better than other types of leather. This is because only pigskin has bristle follicles that extend completely through the hide. Pigs are omnivores. The wild species eat a wide variety of foods, including leaves, roots, fruit, reptiles, rodents, and carrion. Domestic pigs are normally fed diets of corn, grain, root and tuber crops, dairy by-products, commercial feeds, and edible garbage. Male pigs are called boars; the females are called sows. A shoat is a young, weaned pig of either sex. A male pig that has been castrated before reaching sexual maturity is referred to as a barrow, whereas a male pig that was castrated after reaching maturity is called a stag. A gilt is a sow that has never given birth.

pigeons Taxonomically, pigeons and doves are the same. Both are members of the order Columbiformes, family Columbidae. The term dove is generally used for smaller species with pointed tails. "Pigeon" refers to the larger species with square or rounded tails. Pigeons and doves are found throughout the world except in the polar regions and the most remote islands. Various species have adapted to life on farmlands, in woodlands, in scrub deserts, at high altitudes, and in cities. In many regions they are considered game birds and are hunted for food. Common species are often used in scientific research because of their abundance and availability. Wild pigeons are susceptible to parasites, particularly lice. Trichomoniasis is a disease caused by a parasite that lives in the bird's liver, throat, and lungs. Serious outbreaks have killed thousands of mourning doves.

placenta An internal organ providing nourishment to and removing waste products from the blood of an unborn young. The unborn young's blood is conveyed to the placenta via the umbilical cord.

plant Wherever there is sunlight, air, and soil, plants can be found. On the northernmost coast of Greenland the Arctic poppy peeps out from beneath the ice. Mosses and tussock grasses grow in Antarctica. Flowers of vivid color and great variety force their way up through the snow on mountainsides. Many shrubs and cacti thrive in deserts that go without rain for years at a time, and rivers, lakes, and swamps are filled with water plants. The scientists who study plants (botanists) have named and described nearly 500,000 different kinds of plants. They estimate that another 500,000 undiscovered species exist in less explored ecosystems such as tropical forests. In addition, about 2,000 new kinds of plants are discovered or developed every year.

plant exudates Substances produced by trees at the sites of insect and other damage.

plantigrade Relating to an animal that walks on the sole of its feet with the heel touching the ground; as opposed to digitigrade

plastron The plastron is the bony plate that forms the underside of a turtle's shell, covering its belly.

plover Some of the greatest bird travelers are plovers. They are found in most parts of the world, and those nesting in the north are strongly migratory. Those in the western range travel, presumably nonstop, to groups of islands in the South Pacific. Plovers are members of the shorebird family. They are small, ranging from 6 to 12 inches (15 to 30 centimeters) in length. They are plump-breasted birds with long wings, moderately long legs, short necks, and straight bills that are shorter than their heads. Many species are plain brown, gray, or sandy above and whitish below. The females usually lay four dark-spotted eggs in nests on the ground.

Many plovers feed by running along beaches and shorelines, snapping up small aquatic, invertebrate animals. Others, like the killdeer of upland meadows and grasslands, feed chiefly on insects. Plovers and their relatives are quick to give alarm. When flushed, they take swift and direct flight. Many utter melodious whistled calls. Plovers belong to the family Charadriidae.

podzolization A process of soil formation, especially in humid regions and often under coniferous or mixed forest , involving principally leaching of the upper layers with accumulation of material in lower layers and development of a group of soils (the soils are called "podzols") that have an organic mat and a thin organic-mineral layer above a gray leached layer resting on a dark illuvial horizon enriched with amorphous clay.

polyandrous Referring to a mating system in which a female mates with several males during one breeding season

polyestrus Referring to a female that has two or more estrus cycles in one breeding season

polygamous A mating system where an individual has more than one mate per breeding season

polygynous Referring to a mating system in which a male mates with several females during one breeding season

polyphagous Referring to an animal that feeds on many kinds of food.

population A group of animals of the same species that occupies a particular area; usually refers to a group that is somewhat separate from other groups of the same species.

predator An animal that eats other animals.

prehensile Capable of, or adapted for, grasping

proboscis A long, flexible nose or trunk

promiscuous Referring to a mating system where a member of one sex mates with more than one member of the other sex, and each relationship is ephemeral and terminates after mating without a social bond being formed.

protected A species that is shielded from something that might destroy it.

pygmy a miniature copy of the original

p n

BE AWARE. BE CONCERNED. SAVE THE ANIMALS. SAVE US. SAVE THE EARTH.

This website is designed and maintained by Pia Belardo .
Graphic images concept from Pia Belardo . Since 04.03.1996 Updated 10.30.2001
© Copyright 1996 - 2001 EESP. All rights reserved.