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Horses are mammals and give birth to live young. This foal looks like its mother, only smaller. Both horses have a tail, brown hair, two eyes, and four legs.

A mother lynx gives birth to live cubs. There can be one to four cubs in a litter.

Life CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife CyclesLife Cycles

Newborn lynx

The ostrich is the largest bird. It’s not surprising that ostriches lay very large eggs.

Ostrich egg

Robins hatch from eggs. Dogs give birth to live puppies. What do dogs and robins have in common?

Active ReadingActive Reading As you read these two pages, circle words that show differences between animal life cycles.

Most animals have male and female parents. But not all animals reproduce, or have young, in the same way. You can investigate how animals go through changes in their life cycles. Birds and some fish, reptiles, and amphibians lay eggs. Other animals, such as mammals, give birth to live young. These early stages are part of each animal’s life cycle. The offspring have the same number of limbs as their parents.

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The cycle begins again with a new litter of lynx cubs.

What’s Next?Draw the next stage in the ostrich life cycle.

Newborn lynx

An ostrich chick depends on its mother to bring it food.

All grown up, an adult female can find a mate and reproduce.

Ostrich chick Adult ostrich

A young lynx grows into an adult and finds a mate. The two adult lynxes reproduce.

Adult lynxA young lynx grows up in the protection of its mother. A young lynx looks much like its parents, only smaller.

Lynx cub

Investigate and compare the changes that the lynx and ostrich go through in their diverse life cycles.

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