Unlike mammals, birds incubate their eggs outside their body. The underlinedword means

Definition of the Underlined Word

The underlined word "incubate" refers to the process by which birds keep their eggs warm and protected to enable proper development until they hatch. Incubation is typically achieved by the bird sitting on the eggs to provide heat, often using their body warmth. This is different from mammals, which typically develop their young internally in the womb.

Contextual Understanding

In the sentence, it highlights a notable distinction between mammals and birds regarding reproductive behaviors. While mammals carry and nurture their offspring within their bodies, birds rely on external methods to ensure their eggs are kept at the right temperature and condition needed for embryonic development.

Summary

In summary, "incubate" in this context means to keep the eggs warm and conducive for growth until the hatchlings are ready to emerge. This method is crucial for the survival and development of bird eggs, showcasing the diverse reproductive strategies in the animal kingdom.