spring | Ask Dr. Universe | Washington State University

Why do so many animals give birth in spring? — Nova, California

May 7, 2026 melissamayer

Dear Nova,

Nothing says “spring” like frolicking baby animals.

I asked my friend Michela Ciccarelli why so many babies arrive then. She’s a veterinarian at Washington State University. She specializes in animal reproduction.

It turns out lots of mammals are seasonal breeders. That’s a strategy to make sure their babies come at the best time.

“It’s an evolutionary adjustment,” Ciccarelli said. “Spring is the time of year where it’s getting warmer. There’s enough forage to make sure lambs, kids, foals and calves survive.”

If those baby animals were born in the winter, their moms might find less food—and they need that food to … » More …

Dr. Universe: What is inside a blade of grass and why is it green? Green is my favorite color. We really like reading your articles in our newspaper. – Luke, 5, Ogden, Utah

May 1, 2020 jaime.chambers

Dear Luke,

I’ve been wondering the same thing lately. Every time I go on walks, I notice new splashes of color. Watching bugs in the grass, I pretend they’re crawling through a jungle. Everything is bright and bursting with green.

When I saw your question, I knew Michael Neff would know the answer. Green is his favorite color, too. (In fact, when we talked over video, he wore a green Hawaiian shirt.) Neff researches plants at Washington State University, and he is especially curious about grasses.

If you chopped a piece of grass and looked at it with your eyes alone, you might not see much. But if you looked at it under a microscope, you’d see tiny structures containing even tinier parts.