Baby boom: with scientists' help, pandas are now raising healthy cubs in captivity. These baby bears could keep the species from disappearing.Last year, a California celebrity left her sunny home for a new address. The star: a popular panda panda, name for two nocturnal Asian mammals of the order Carnivora: the red panda, Ailurus fulgens, and the giant panda, Ailuropoda melanoleuca. named Hua Mei (WAH n. 1. (Zool.) The panda. MAY). The bear first grabbed headlines when she was born at the San Diego Zoo San Diego Zoo One of the world's largest collections of mammals, birds, and reptiles, located in San Diego, Calif., and administered by the Zoological Society of San Diego. The 100-acre (40. in 1999. She was the first Giant Panda, Ailuropoda melanoleuca Ailuropoda melanoleuca giant panda. See panda. (AL-yer-uh-POH-dah mel-AN-uh-LOO-kah), in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. to survive after being born in captivity. Hua Mei stayed at the zoo until she was old enough to have cubs. Then, last February, she moved to China's Wolong (WOO-long) Giant Panda Breeding and Research Center. There, as part of an international project to breed pandas, scientists introduced Hua Mei to potential mates. And last September, she made headlines again--this time after delivering two cubs. "We still think of her as our baby; now she has twins of her own," says Barbara Durrant, the head reproductive physiologist (scientist who studies reproduction) at the San Diego San Diego (săn dēā`gō), city (1990 pop. 1,110,549), seat of San Diego co., S Calif., on San Diego Bay; inc. 1850. San Diego includes the unincorporated communities of La Jolla and Spring Valley. Coronado is across the bay. Zoo's Department of Conservation and Research for Endangered Species endangered species, any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in accordance with the U.S. . Hoping to save pandas from extinction (no organisms of the species remain), biologists around the world are working together to try to breed the bears in captivity. As part of the project, China--panda's native land--lends pandas (like Hua Mei's parents) to foreign zoos with the hope that the bears will have cubs. Then, the offspring leave mom and dad behind and move to Chinese breeding centers to start a new family. "BEARLY" HANGING ON With fewer than 1,600 wild pandas remaining, scientists think captive-born bears may help rescue wild pandas one day. The bears once roamed over most of China and into other countries to the south. But humans have taken over most of their forest home (see map, right). "Pandas have been pushed to the edges of China that humans do not want to live in," says Colby Loucks, a conservation scientist at the World Wildlife Fund. Squeezed into small, isolated patches of steep forest, the bears' lives are at risk. For instance, bamboo bamboo, plant of the family Gramineae (grass family), chiefly of warm or tropical regions, where it is sometimes an extremely important component of the vegetation. It is most abundant in the monsoon area of E Asia. makes up about 99 percent of a panda bear's diet. In the 1980s, large patches of China's bamboo died off. Surrounded by humans, over 200 wild pandas were unable to move to areas where bamboo still grew and the bears starved starve v. starved, starv·ing, starves v.intr. 1. To suffer or die from extreme or prolonged lack of food. 2. Informal To be hungry. 3. To suffer from deprivation. to death. To prevent another disaster, scientists are working to protect panda habitat (region where an animal lives). Then, they may be able to boost the panda population one day by releasing captive-born bears into the wild. PERFECT TIMING For now, scientists are trying to learn how to breed pandas in captivity. Their first step with Hua Mei: setting her up on several blind dates. Captive male pandas are very picky pick·y adj. pick·i·er, pick·i·est Informal Excessively meticulous; fussy. picky Adjective [pickier, pickiest] Brit, Austral & NZ about their female partners. The scientists needed to find Hua Mei's perfect match. The next step--choosing the moment to introduce the bears to each other--was even trickier. That's because a female panda's estrus estrus Period in the sexual cycle of female mammals, except the higher primates, during which they are in heat (ready to accept a male for mating). Some animals (e.g., dogs) have only one heat during a breeding season; others (e.g. , the time during which she can become pregnant, occurs only once a year for one to four days. During this time, the female produces an egg (female sex cell). The egg then needs to be fertilized fer·til·ize v. fer·til·ized, fer·til·iz·ing, fer·til·iz·es v.tr. 1. To cause the fertilization of (an ovum, for example). 2. , or joined, with a sperm (male sex cell). Unfertilized Adj. 1. unfertilized - not having been fertilized; "an unfertilized egg" unfertilised, unimpregnated infertile, sterile, unfertile - incapable of reproducing; "an infertile couple" eggs don't survive long, so fertilization fertilization, in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, followed by the joining of their nuclei. needs to happen quickly. "[There is] a very, very small window--about 24 hours [in which fertilization can occur]," says Durrant. In the wild, solitary female pandas call out to alert nearby males that the time is right. In captivity, scientists need to introduce pandas--normally kept separated--to each other during this period. If fertilization occurs, a single cell called a zygote zygote: see reproduction. forms from the joined egg and sperm. Then, a cycle of cell divisions begins to form a panda fetus fetus, term used to describe the unborn offspring in the uterus of vertebrate animals after the embryonic stage (see embryo). In humans, the fetal stage begins seven to eight weeks after fertilization of the egg, when the embryo assumes the basic shape of the newborn (unborn young) and eventually a cub (see Nuts & Bolts, p. 11). CARE BEARS It turned out that everything was timed right for Hua Mei, and she gave birth to twins--each only about the size of a stick of butter. "The size ratio of a panda mother to her cub is the largest of any bear and one of the largest of any animal," says Durrant. Their extra-small size means the cubs need a lot of care. Like many new morns, Hua Mei initially seemed unsure of her motherly moth·er·ly adj. 1. Of, like, or appropriate to a mother: motherly love. 2. Showing the affection of a mother. adv. In a manner befitting a mother. role. Soon, however, she settled into motherhood. Since all panda cubs are born blind and hairless, moms gently pick them up in their mouths. They keep the tiny cubs cozy See COSE. against their fur. A panda mother usually won't leave her baby--even to eat or drink--until the cub is about 10 days old. She stays with her cub, teaching it how to survive, until it is about 18 months old. Then the cub leaves to live a mostly solitary life. In captivity, panda cubs are slowly weaned wean tr.v. weaned, wean·ing, weans 1. To accustom (the young of a mammal) to take nourishment other than by suckling. 2. , or removed from their mother's care, after roughly one and a half years. DOUBLE TROUBLE It's tough to care for even one growing bear, but--like Hua Mei--pandas give birth to twins about 50 percent of the time. Because the cubs need so much attention, a mother in the wild usually neglects one of her twins. "The cubs are so small and require so much care, she just can't hold [or feed] two of them all the time," says Durrant. Unfed, the neglected cub dies. Even captive pandas follow these instincts. So in the past, when twins were born in captivity, veterinarians Veterinarians and veterinary surgeons (vets) are medical professionals who operate exclusively on animals. Well-known and notable veterinarians include:
CUBS WIN Luckily, scientists have now developed liquid formulas that are better matched to natural panda milk. Also, they have designed special "cub holders" that exactly copy the position in which mother pandas hold their babies when they nurse. Scientists use take fur that feels and smells just like mom to help a cub feel right at home. Hua Mei's twins also benefit from another new technique: Instead of completely hand-raising one cub, veterinarians periodically swap twins. They remove the cubs from the mother's care one at a time--feeding each for a few hours before returning it. Each cub gains from spending time "Spending Time" is the first single released by Christian artist Stellar Kart. The lyrics describe the band members desire to spend "more time with God". "Sometimes it’s a real struggle to spend time with God. with morn: "Since twin swapping and improved formulas have been used at Wolong, they went from losing one of the twins 100 percent of the time to saving both twins 100 percent of the time," says Durrant. This success is spreading: In 2003, 16 healthy pandas were born in captivity around the world. This baby boom--along with expanded protection of wild habitat--may help keep the black-and-white bears from disappearing. Nuts & Bolts Like all animals, pandas start out as a single cell. Through a process called mitosis, this cell divides over and over again. These divisions form millions of cells that eventually develop into a panda cub. 1. CELLS UNITE A male sperm joins with a female egg. Result: a zygote, or fertilized egg. The nucleus (area containing DNA--chemical that carries genetic information) has 42 chromosomes (structures that contain DNA DNA: see nucleic acid. DNA or deoxyribonucleic acid One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. ), half from each parent. Four chromosomes are shown. 2. DUPLICATION The nucleus breaks down and each of the cell's chromosomes is copied. The chromosome pairs line up, moving along spindle fibers spindle fiber n. One of a network of achromatic filaments that extend inward from the poles of a dividing cell, forming a spindle-shaped figure. . Each pair splits and one complete set of chromosomes moves to each end of the cell. 3. CELL DIVIDES Two new nuclei nuclei /nu·clei/ (noo´kle-i) [L.] plural of nucleus. nu·cle·i n. Plural of nucleus. nuclei plural of nucleus. form at opposite ends of the cell. Each nucleus contains a set of 42 chromosomes. Then, the cell divides into two identical cells. 4. CELLS MULTIPLY The new cells continue to divide: After one more cycle of cell divisions, four identical cells have formed. Another cycle yields eight cells. This continues--doubling the number of cells each time. 5. REORGANIZATIDN After about five days, a blastocyst blastocyst /blas·to·cyst/ (-sist) the mammalian conceptus in the postmorula stage, consisting of an embryoblast (inner cell mass) and a thin trophoblast layer enclosing a blastocyst cavity. forms: Cells move to form a thin layer around the edge and a group of small cells, called the inner cell mass in·ner cell mass n. The mass at the embryonic pole of the blastocyst concerned with the formation of the body of the embryo. , assembles along one side. 6. ATTACHMENT Eventually, the blastocyst attaches to the lining of the female panda's uterus, the hollow organ in which a baby develops. The cells in the inner cell mass grow to become a panda fetus. 7. CUB DEVELOPS For between 30 to 50 days, the fetus grows inside the uterus. Then, the female delivers a baby panda. At birth, the tiny cubs are blind and hairless. [ILLUSTRATION OMITTED] MAMA BEAR: Hua Mei tends to one of her one-day-old twins. Cubs cry to get mom's attention. [ILLUSTRATION OMITTED] TINY TOT: One of Hua Mei's twins--about one month old--tries to lift itself up. [ILLUSTRATION OMITTED] BEAR HUG Bear Hug An offer made by a company to buy the shares of another company that is too high for the board of the target firm to refuse. Notes: If the target company says the merger is okay but they want a higher price, it is called a "teddy bear hug. : An attentive mom at the Wolong Center cuddles Cuddles may be:
[ILLUSTRATION OMITTED] DID YOU KNOW? * For many years, scientists were puzzled by how to classify giant pandas. Many thought that pandas should be in the same family (classification of organisms above genus) as raccoons. But studies of the giant panda's DNA (chemical that carries hereditary information) have proved that the black-and-white animals are bears. However, they are different enough to be placed in a subfamily subfamily /sub·fam·i·ly/ (sub´fam-i-le) a taxonomic division between a family and a tribe. sub·fam·i·ly n. A taxonomic category ranking between a family and a genus. separate from other bears. CRITICAL THINKING: * Some conservation scientists say that funds used for breeding pandas in captivity would be better spent to conserve wild pandas and their habitat. Debate this issue. CROSS-CURRICULAR CONNECTIONS: HISTORY: The giant panda was unknown to the Western world until a French missionary named Armand David The standard author abbreviation David is used to indicate this individual as the author when citing a botanical name. Father Armand David (September 27, 1826 near Bayonne –November 10, 1900 in Paris) was a Lazarist missionary Catholic priest as well as a zoologist stumbled upon one while hiking in a remote Chinese forest in 1869. Imagine you are David. Research and then write a journal entry describing the hike that ]ed to the encounter. RESOURCES * For fun facts plus activities about pandas, check out: http://nattionalzoo.si.edu/Animals/GiantPandas/ PandasForKids/default.cfm * To see Hua Mei!s development from a helpless cub into a grown bear, see: www.liu.edu/cwis/cwp/library/ exhibits/panda/panda.htm Name: -- DIRECTIONS: On a separate piece of paper, use details from the article to help you write the following: 1. You are a scientist in charge of breeding pandas at a world famous zoo. Describe to visitors why it is so biologically challenging to successfully breed a panda in captivity. 2. Write the text for a zoo brochure describing how scientists are helping raise panda cubs in captivity. 1. It is extremely challenging to breed pandas in captivity. First, you need to introduce potential panda mates. In captivity, male pandas are extremely picky about their female partners. More challenging: Picking the moment to introduce the bears. That's because a female panda's estrus, the time during which she can become pregnant, occurs only once a year for one to four days. During this time, the female produces an egg (female sex cell). The egg then needs to be fertilized, or joined, with a sperm (male sex cell). Unfertilized eggs don't survive long, so fertilization needs to happen quickly. For pandas, the window that fertilization can occur is very small--about 24 hours. If fertilization occurs, a cell called a zygote forms from the joined egg and sperm. Then, a cycle of cell divisions begins to form a panda fetus (unborn young) and eventually a tiny cub. 2. Pandas give birth to twins about 50 percent of the time, with each only about the size of a stick of butter. Because the cubs are so small and need so much attention, a mother in the wild usually neglects one of her twins, and the neglected cub dies. Captive pandas naturally follow these instincts. In the past, when twins were born in captivity, veterinarians removed one of the cubs and handraised it. But until recently, scientists had never successfully handraised a cub to adulthood. Luckily, scientists have now developed liquid formulas that are better matched to panda milk. They have also designed special "cub holders" that exactly copy the position in which mother pandas hold their babies when they nurse. Also, since the cubs are born blind and hairless, rooms gently pick up their cubs in their mouths and keep the cubs cozy against their fur. Morn usually won't leave her baby--even to eat or drink--until the cub is about 10 days old. To help a hand-raised cub feel right at home, scientists created fake fur Fake fur, fun fur, or faux fur is any material designed to resemble fur, normally as part of a piece of clothing. It is also used in purses,bags, and multiple other objects. Typically it is made of synthetic fibers. that feels and smells just like morn. Another new technique: Instead of completely hand-raising one cub, veterinarians periodically swap twins. They remove the cubs from the mother's care one at a time-feeding each for a few hours. PANDA-MONIUM [ILLUSTRATION OMITTED] CROSSWORD ACROSS 1. Number that stands for "nothing" * 4. The first step in breeding pandas: set them up on a blind -- * 8. To comfort panda cubs, zoos use fake -- that feels and smells like a panda mom 9. Place where digestion occurs 11. Stop or -- * 13. In the 1980s, large patches of Chinas bamboo died -- * 15. Unborn young 18. Protective gas in the upper atmosphere 20. Famous poet: -- Allan Poe * 22. Female sex cell 25. "-- apple a day keeps the doctor away" 26. The "foot" of a cat or dog * 28. Hua Mei's birthplace: the San Diego -- * 30. Removing Hua Mei's cubs one at a time for care: -- swapping * 31. Sperm: male sex -- DOWN * 1. Cell formed after fertilization 2. Right field (abbr.) * 3. Extinction: a species dies -- 5. Silver (chemical symbol) 6. A ballerina's skirt 7. Extra-terrestrial (abbr.) 11. The Wizard -- Oz * 12. Panda moms usually won't leave a cub until it's -- days old 14. Layer of clouds near the ground 15. TV show: Grounded -- Life 16. Peg that holds a golf ball 17. SOS SOS, code letters of the international distress signal. The signal is expressed in International Morse code as … — — — … (three dots, three dashes, three dots). is a type of distress -- 19. Zig -- 21. To sketch 23. This state's fruit is the peach (postal code Noun 1. postal code - a code of letters and digits added to a postal address to aid in the sorting of mail postcode, ZIP code, ZIP code - a coding system used for transmitting messages requiring brevity or secrecy ) 24. One of Snow White's seven dwarfs IBM's early competitors in the mainframe business: Burroughs, CDC, GE, Honeywell, NCR, RCA and Univac. Seven Dwarfs Doc, Happy, Sleepy, Sneezy, Bashful, Grumpy, Dopey. [Am. , who wears glasses 26. Platinum (chemical symbol) 27. Home state of the Green Bay Packers (postal code) 29. Old English Old English: see type; English language; Anglo-Saxon literature. Old English or Anglo-Saxon Language spoken and written in England before AD 1100. It belongs to the Anglo-Frisian group of Germanic languages. (abbr.) * Starred clues relate to this issue's stories. [ILLUSTRATION OMITTED] PRODUCING PANDAS Name: -- Directions: First, read "Baby Boom" (p. 8). Then, use the Nuts & Bolts diagram on page 11 to help you fill in the letter to the correct answer below. 1. A zygote forms (A) from mitosis. (B) after one cycle of cell division. (C) with chromosomes from only the female. (D) when a male's sperm joins with a female's egg. 2. During mitosis, which of the following occurs first? (A) The cell divides into two identical cells. (B) The chromosomes are copied. (C) The chromosomes line up along the spindle fibers. (D) Two new nuclei form. 3. The zygote cell in step 1 of the diagram contains 42 chromosomes. How many chromosomes are inside the cell in step 2? (A) 21 (B) 42 (C) 63 (D) 84 4. Which of the following is NOT true about the two cells shown in step 3 of the diagram? (A) Each cell contains 21 chromosomes. (B) The cells each contain a nucleus. (C) The cells formed after one cell split in half. (D) The cells are identical. 5. How many cells are shown in step 4 of the diagram? (A) 1 (B) 8 (C) 9 (D) 16 6. If a cycle of cell divisions starts with one cell, how many cells would have formed after three cycles? (A) 3 (B) 6 (C) 8 (D) 10 7. The -- grows into a panda fetus. (A) inner cell mass (B) spindle fiber (C) outer cell layer (D) lining of the uterus 1. d 2. b 3. d 4. a 5. b 6. c 7. a |
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