Do Birds Only Lay Eggs in Spring? Female cardinal feeding babies in the nest. Bird nesting happens in spring. That's common knowledge, right? Actually, it's not always the case. Even though we ...

A new study has uncovered a fundamental link between brain size and offspring size, helping to solve a long-standing evolutionary puzzle: Why do birds lay such disproportionately large eggs?

Perhaps the most famous nest hijacker in the bird world, the common cuckoo has even given rise to the phrase “cuckooing.” A female cuckoo carefully watches her host bird, usually small songbirds like ...