Animals that Lay Eggs
Animals that lay eggs are called “Oviparous.” The embryo develops inside the egg.
- Birds: All birds are oviparous, laying eggs with hard shells. The parents usually incubate the eggs until they hatch.
- Reptiles: Most reptiles, including snakes, turtles, lizards, and crocodiles, lay eggs.
- Amphibians: Frogs, toads, salamanders, and newts are examples of oviparous animals. They lay eggs in water or moist environments, usually with a jelly-like coating.
- Fish: Many fish species are oviparous, laying eggs in various ways. Some fish lay adhesive eggs that stick to surfaces, while others release eggs into the water.
- Insects: The majority of insects are oviparous. Insects like butterflies, bees, ants, and beetles lay eggs in specific locations suitable for developing their offspring.
Protection from Predators
Animals that lay eggs have evolved adaptations to ensure their offspring’s survival.
- They lay eggs in a safe environment, such as nests or burrows.
- Some animals lay their eggs in locations that provide natural camouflage, making them less visible to predators.
- Some insects lay eggs that mimic the appearance of their surroundings. This mimicry makes it difficult for predators to locate the eggs.
- Parents actively guard the eggs in some fish species to protect them from potential threats.
- Many oviparous animals produce many eggs at a time, increasing the chances of surviving predator attacks.
Animals that Give Live Birth
Animals that give live birth are called “Viviparous.” Viviparous animals carry their developing offspring internally. The parent nourishes the embryo through special structures like the placenta.
- Mammals: Most mammals, including humans, dogs, cats, elephants, whales, and many more, give live birth.
- Some Reptiles: While most reptiles lay eggs, some, certain species of snakes and lizards, give birth to live young.
- Some Fish: Certain species of sharks and rays give birth to live young instead of laying eggs.
- Some Amphibians: The Surinam toad is known for giving birth to live young that emerge from small pockets on the mother’s back.
- Marsupials: Animals like kangaroos, opossums, and koalas carry their offspring internally for a much shorter time and then let them develop inside a pouch
Here are some fun facts about animals that lay eggs versus give live birth:
- Cuckoos lay their eggs in the nests of other bird species, tricking them into raising their young.
- Some species of sea turtles exhibit mass nesting events where hundreds or even thousands of females come ashore to lay eggs simultaneously.
- Reptile eggs have leathery or calcified shells that provide protection. Crocodile eggs have a hard, calcified shell.
- Gestation period is the amount of time an offspring develops inside the mother’s womb. The shortest gestation period is around 12 days in the Virginia opossum, while the longest is over 22 months in elephants.
Let’s quickly recap what we learned about animals that lay eggs versus give live birth:
- Which type of animal usually incubates its eggs until the baby is hatched? Birds
- Where do amphibians usually lay their eggs? Water or Moist Environments
- Which type of animal has a shorter gestation period and then grows inside a special pouch? Marsupials
- What are the two types of shells that reptile eggs have? Leathery or Calcified Shells