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?

What really did come first--the chicken or the egg? Birds' reproductive biology is dramatically different from that of any other living vertebrates, and ornithologists and paleontologists have long ...

Unfortunately, this book can't be printed from the OpenBook. If you need to print pages from this book, we recommend downloading it as a PDF. Visit NAP.edu/10766 to get more information about this ...

Climate change has now become one of the biggest threats to ecosystems globally, as global cycles that have helped species thrive for centuries have shifted. Birds in particular, for their elaborate ...

A new study reported in the Proceedings of the National Academy of Sciences has assessed changes in the reproductive output of 104 bird species around the world between 1970 and 2019. The study ...