Where have the butterflies gone?
Tribune reporter Kaytlyn Leslie asked why in a story published Jan. 2, 2019, after the Pismo State Beach Butterfly Grove recorded a record low number of butterflies wintering in the area this season.
Butterflies have long been a notable part of the county.
A June 9, 1925, article in the San Luis Obispo Daily Telegram described the road from Morro Bay to Atascadero as the “Butterfly Route.”
Pacific Grove had fame at that time as the home of the Monarch Butterfly.
In 1969, the Santa Lucia chapter of the Sierra Club was hosting annual butterfly marches at Pismo Beach State Park.
By the early 1980s, the butterflies had become an annual pilgrimage for Telegram-Tribune photographers and environment writers. They were spectacular to photograph even before the newspaper began regular color printing.
Researchers were catching and tagging the insects at the time to learn more about their migration. The science may be more evolved these days, but the following story by Patricia Porter, edited for length, from Dec. 23, 1989, is interesting nonetheless:
Reign of the Monarchs
We were standing by the Refrigerator Trees when what looked like clusters of leaves suddenly turned into a cloud of butterflies.
Thousands of monarchs filled the sky.
“They’re like kids in a group,” said monarch maven Dick Simpson.
“Someone steps on someone else’s foot. Some little thing triggers them, and off they go.”
There’s a lot to learn about monarch butterflies and their habitat, Simpson told a group of senior citizens touring the Pismo State Beach Butterfly Trees earlier this month.
The former elementary school principal throws in a few jokes.
“What do a butterfly and an elephant have in common?”
Both have proboscis.
“That’s a fancy word for trunk or straw,” with the butterfly uses to sip nectar, Simpson explains.
And did you know, butterflies have taste buds in their feet?
“Why isn’t that a problem?” asked Simpson.
“They don’t wear socks and they don’t walk.”
But there are more questions than answers when it comes to monarchs, as Simpson has discovered in his six years as a docent for the Natural History Association.
What brings the orange and black flyers back to Pismo State Beach year after year? And what’s the big attraction of the nondescript-looking grove of pine and eucalyptus that Simpson likes to call the Refrigerator Trees?
Simpson listed some of the reasons.
It’s a perfect habitat, cool but not too cold, with lots of subtle gradations in between.
The trees are different heights and have many limbs, so when the weather gets too chilly the butterflies can move up toward warmer temperatures.
Even in deepest winter, they can sun themselves, said Simpson, pointing to an opening high above the treetops.
A nearby stream provides water, and an undershelf of moss makes the area cool and moist. That prevents the monarchs’ metabolism from over heating during what’s essentially a period of hibernation.
The monarchs arrive in late fall. Come February, they’re ready to leave.
The female lays her eggs on the underside of a milkweed leaf. Within a month, a new generation is ready to start the trip to its summer grounds.
Simpson says the monarch is the only butterfly that makes a full round-trip migration.
They come to roosting sites in California from as far away as the Continental Divide.
Last year, the Butterfly Trees in Pismo Beach was the most populous site, with 80,000 monarchs. Other big draws are in Santa Cruz and Goleta. All are located in groves of trees within a half-mile of the ocean, where the nights are warm and the days are cool.
Locally, the monarchs can be seen at Morro Bay State Park and Sweet Springs Reserve in Los Osos, and near the Surf and Sand Trailer park in Oceano. Simpson says there are also “temporary bivouacs” in Grover City and Halycon.
Monarchs need a very special microclimate. Unfortunately, what attracts butterflies also attracts developers, according to Simpson.
Pacific Grove once famous for its monarchs, but development has wiped out many roosting sites.
“They charged a $500 fine for harming any monarch, but what they didn’t do is protect the reason the monarchs were there. They didn’t protect the roosting sites.”
That’s why scientists call the monarch an endangered phenomenon, not an endangered species, Simpson explains.
Simpson hopes tours like his will increase people’s sensitivity to the monarch.
Most butterflies live three for four weeks, whereas wintering monarchs can live several months. The annual cycle starts in the summer, when a female lays her eggs on a milkweed, growing from a sixteenth of an inch to 2 inches in just two weeks.
“It increases 2,700 times in size,” says Simpson. “If a human grew as much, he’d be the size of a baby blue whale.”
The milkweed also provides protection form predators, because it contains poisonous alkaloids, according to Simpson.
A full-grown caterpillar finds a sheltered place on a limb or fencepost. It lays down a little silken pad and hangs upside down from a hook at the end of its tail.
It forms a chrysalis, or cocoon, an emerald green casing with gold spots. During the next two weeks, the caterpillar’s body dissolves into a living soup and reconstitutes itself into a butterfly.
The egg-to-adult-process takes 28 to 35 days, depending on the weather.
All summer, the butterflies lay their eggs in the milkweed. But in late August or September, they change their lifestyle, said Simpson.
“Instead of mating immediately and leading the fast life, they abstain and go into reproductive diapause.
“They build up body fat. Some of them become quite plump.”
The shortening days soon signal it’s time for another change.
From the East Coast they head for El Rosario, 60 miles north of Mexico City. Western butterflies zero in on the Pacific coast.
Up to 5 million come to California; as many as 100 million turn up at El Rosario, according to Simpson.
The only difference between the monarch migration and bird and fish migrations is that it takes several generations of monarchs to make the round trip.
Still, individual butterflies have made some pretty amazing treks. One butterfly that Simpson tagged later turned up near Sacramento. Another is on record as having flown from Goleta all the way to Zion National Park in Hurricane, Utah.
Its still a mystery how they manage to return to the same trees.
Perhaps it’s their sense of smell, which is 2,000 times keener than ours, says Simpson.
“My hunch is, one reason they come back to these trees is there’s a certain amount of scent that stays here throughout the year. There’s not much rain to wash it away.”