Debbie Ann Straml, age 12 of Allentown, Pennsylvania, for her question:

Which is the biggest newborn baby animal?

We would expect this champion to be a mammal because an unborn mammal has time to develop through a gestation period inside his mother’s body. We would expect the biggest mother mammals to give birth to the biggest babies, though this is not always so. A five foot, 150 pound mother kangaroo gives birth to a bitsy one ounce baby. However, in the field of champions, the world’s biggest animal baby belongs to the world’s biggest mother.

The earth’s most successful animals are the furry, warm blooded, air breathing mammals. Without a doubt their success is related to their birth and family life. Aside from the platypus and his few cousins, all mammal babies are born alive, and all mammal babies are fed on milk. All mammal babies have responsible parents who tend them through childhood and educate them to make their way in their own environments. Birds also are excellent parents, but their babies hatch from smallish eggs and their rate of infant and child mortality tends to be quite high.

The largest land animal is the elephant. And, as you would expect, this whopping mammal gives birth to a whopping infant. A mother elephant seven feet tall may weigh around four tons. After a gestation period of 21 months, she gives birth to a 200¬     `pound infant, standing 3 1/2 feet tall. In a few days the capable youngster is able to keep up with the herd, though he depends on mother’s milk for the first six months of his life.

However, the world’s largest mammals are the sea going blue baleen whales. Mrs. B. B. Whale may be 100 feet long and weigh 100 tons. After a gestation period of about one year, she gives birth to the world’s largest infant. He measures 24 feet long and weighs about four tons. Junior is born at sea, already knowing how to swim. But being a mammal he immediately needs a breath of air. Naturally his loving mother has the inborn know how to help him. She gives birth near the surface and quickly nuzzles him up, up to gasp his first breath and fill his lungs with air. Then she tenderly guides him to fill his hungry tummy with mother’s milk.

In a day or so, the world’s biggest baby is keeping up with his gigantic aunts and uncles, plus cousins of assorted sizes. In six months he graduates from mother’s milk to a diet of plankton. By his 14th birthday he is an adult and with luck can expect a life span of about 50 years. Mrs. B.B. Whale is more than four times longer and maybe 25 times heavier than her infant. By comparison, the babies of the smaller whales are larger. A baby sperm whale is nearly half as long as his 30 foot mother. A 40 foot grey whale gives birth to a 16 foot infant. Compared with his mother, the infant blue baleen whale is not a giant    but he is still the largest baby born on our planet.

A baby whale is almost always an only child. Babies that arrive in litters tend to be smaller. A 400 pound tiger bears a litter of two to six cubs, each weighing only about 2 1/2 pounds. The mouse sized baby kangaroo breaks all these general rules. He arrives after only a month or so of gestation and takes the next six months to complete his development inside his mother’s cozy, fur lined pouch.