Are Bird Eggs Fertilized Externally?

Birds reproduce by internal fertilization, during which the egg is fertilized inside the female. Like reptiles, birds have cloaca, or a single exit and entrance for sperm, eggs, and waste. The male brings his sperm to the female cloaca. The sperm fertilizes the egg.

How is a bird egg fertilized?

Birds reproduce by internal fertilization, during which the egg is fertilized inside the female. Like reptiles, birds have cloaca, or a single exit and entrance for sperm, eggs, and waste. The male brings his sperm to the female cloaca. The sperm fertilizes the egg.

What animals fertilize eggs externally?

Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes.

James H. Sterling

James H. Sterling

Environmental Science & Climate Journalist

James Sterling reports on renewable energy developments, climate policy, ecological conservation, and green tech innovations around the globe.