Arctic terns have begun their epic migration to their northern grounds. When Arctic terns migrate in Spring, they leave total daylight at the South Pole and arrive at the time of total daylight at the North Pole.
Butterflies require warmth to fly. Most butterflies that are active in early Spring have dark wings that absorb solar heat.
Migrating whooping cranes travel more than 2,000 miles in as few as 10 days. Thanks to the Whooping Cranes Eastern Reintroduction Project, whooping cranes are again nesting in the Necedah National Wildlife Refuge. Their arrival time can be as early as mid-April.
Most people know about the change a caterpillar goes through to become a butterfly, but did you know that they change several times before they get to that? When caterpillar larvae metamorphose, they shed body layers at several stages. The most extreme is what takes place when they morph into butterflies.
Caterpillars hatch from eggs in early to mid-April, which corresponds to the flowering of host plants. They then race to eat enough food before their host plants die back in summer.
About This Week in Nature:
To illustrate the widest range of natural events, I depict the seasonal activities found in the Northern Hemisphere, and I have chosen to present the most intense expressions of each season. My "This Week in Nature" posts are not meant to be specific to any one geographical area. They are intended to evoke the essence of the seasons and to emphasize the cycles of nature. The goal is to simply offer a glimpse of the natural phenomena that make each day an amazing event.