Willow Glen Resident

Letters & Opinions

Mowing the lawn less might bring butterflies

By Moryt Milo

I use to have a butterfly net as a child, and with that net came a hobby kit that would allow me to preserve and mount my specimens. I would often wander for hours through large fields rich with wildflowers and grasses, waiting to come upon one of my prized catches, which included monarchs and black, giant and spicebush swallowtails. I took my hobby quite seriously. It took a great deal of patience and real skill to capture a butterfly without damaging its wings or antennae. If I was home and a butterfly flew into the yard, I would run like mad for my net and chase after it. Most of the time it would escape me.

Years later when I came home for a visit, I was surprised to discover my mother had kept the collection. I happened upon it while digging through a closet. There it was, those large glass frames with my butterflies mounted in neat rows, resting on their bed of cotton. I feel guilty about it, but back then it was OK to capture nature. No one ever believed or considered that butterflies might disappear from our environment.

My only indication of future concern came from a ranger in Yellowstone National Park.

You see, my butterfly net went everywhere with me, including a cross-country family road trip from New York to California. We stopped in Yellowstone, and as we hiked through the park, I had my net in tow. When a yellow swallowtail glided toward me, I started to run after it, but the ranger saw me and said, "This is a national park. You're not allowed to capture a butterfly. Everything stays in the park."

I believe that day was the beginning of my hobby's decline. Even as a 12-year-old, I realized there was something sacred in what the ranger had said. I didn't understand it completely at the time, but I did understand that everything in the park was special. I don't recall using my net much after that except to capture frogs and tadpoles.

Today butterflies continue to hold a special place in my world, only now, I welcome them into my yard with the flowers, trees and shrubs I've planted to attract them.

It's magical when a swallowtail or monarch finds its way into my garden and briefly rests on a flower. Even small butterflies like the bay checkerspot or the white cabbage are a delight.

The checkerspot was a common visitor until the last few years, and I didn't know why until recently when I learned the small insect had been identified as a federal threatened species in 1987. Then I learned that its food and egg-hatching source was purple clover. I use to have a lot of purple and white clover on my lawn, but I thought it looked more tidy if the lawn was mowed. Now I realize in the process I had eliminated the butterfly's habitat.

Then I read about an even stranger connection to the butterflies' dwindling numbers.

Our efforts to control auto emissions affected the small flyer. It turns out that catalytic converters, placed in vehicles to reduce pollution, also had a role to play in the butterfly's downslide. The catalytic converters turned nitrogen-oxide into ammonia, which in turn fertilized the grasses along Interstate 280 and caused rye grass to choke out the clover, the checkerspot's food.

Amazingly, Bay Area biologist Stu Weiss figured it out and is now working to restore the checkerspot in the area. He hopes to accomplish this by mowing the rye grass at the right time of year so the clover has a chance to grow.

In early April, Weiss released a bagful of the small butterflies into Edgewood County Park, with the hope that their numbers will swell. There use to be thousands in the 1990s, then they began vanishing.

Weiss took on the puzzling checkerspot problem because he was fed up with the ongoing extinction of other species.

When I read the story I remembered the park ranger who warned me years ago about the importance of respecting all living things big and small.

I'm crossing my fingers that this simple solution of timed mowing works along Interstate 280. But what's more exciting is I can bring that simple discovery into my own yard. I realize now that the clover blooming on my lawn isn't an untidy problem after all.

Moryt Milo is the editor of Willow Glen Resident. She can be reached at 408.200.1051 or via email at mmilo@community-newspapers.com.