No excess baggage allowed

Arctic Terns have short legs. Comically short legs. Once you see it, you can’t unsee it.

They need as little excess baggage as possible for their epic migration. They complete the longest annual migration of any living animal, flying tens of thousands of miles a year from pole to pole. The survival rate of those birds with slightly longer legs was clearly not as high, due to either cold or weight.

They’re fine-tuned survivalists.