Kingston Leong walks through a dense stand of eucalyptus trees in the Monarch Grove Natural Area in Los Osos, eyes scanning the trees above.
Soon, he finds what he is looking for at the edge of a small clearing. A cluster of monarch butterflies, barely visible in the dappled light, clings to a bough.
“When I first noticed this grove, there were hardly any monarchs here,” he said, examining the aggregation of butterflies through binoculars.
If it weren’t for Leong, the colorful orange insects would probably not be quite as plentiful in the county. The retired Cal Poly biology professor has spent the past 20 years tirelessly studying monarch butterflies and working to improve their wintering habitat in San Luis Obispo County.
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In that time, Leong, 73, has established three monarch groves in the county — the one in Los Osos as well as sanctuaries in Morro Bay and Nipomo. He is also working to get endowments and teams of volunteers in place to manage the three sites in perpetuity.
“I want to have a structure in place so that the program can continue after I’m gone,” he said. “One person can’t do it all.”
He also holds two patents related to monarchs. One is for an artificial larval food for them, and the other is for a method to keep monarch colonies free of protozoa contamination.
Leong became fascinated with monarch butterflies because of their beauty, particularly the pattern of orange and black on their wings.
“Once the sun hits them, they spread their wings, and it’s a colorful mosaic of living things,” he said. “It’s very striking, and I was very impressed when I first saw it.”
Monarch butterflies spend the winter in the coastal areas of San Luis Obispo County to escape freezing conditions inland. Monarchs from all over the western United States congregate here from November to late February, some coming as far as 2,000 miles. Monarchs east of the Rocky Mountains spend the winter in Mexico.
In the decades he has been studying monarchs, Leong has learned that the butterflies do not much care what kind of tree they roost in — mostly eucalyptus and some Monterey pine — but the site has to be shielded from direct wind and get sunlight in the morning and afternoon.
The monarch grove at Pismo State Beach remains the premier monarch clustering site. With about 30,000 of the insects gathered there this year, it is one of the largest such groves in the United States.
But the three sites established and managed by Leong are beginning to rival that site. For example, a eucalyptus grove in the middle of the Morro Bay Golf Course typically gets about half as many monarchs as the Pismo Beach site.
Under the direction of Leong, the San Luis Obispo County Parks Department recently spent $3,000 planting cypress trees around the golf course grove that will eventually act as a wind screen. The cypress trees replace a grove of Monterey pines that had to be removed because they were killed by pine pitch canker disease.
However, the crowning achievement of Leong’s work can be found in Nipomo. Nineteen acres of eucalyptus trees have been set aside in the Trilogy at Monarch Dunes community on the Nipomo Mesa as a monarch butterfly sanctuary.
The Monarch Dunes Butterfly Habitat has an endowment of $250,000 donated by Trilogy’s developers and 24 volunteers who conduct weekly counts of the monarchs and give talks and tours of the grove every Saturday at 11 a.m.
Two interpretive displays tell visitors about the monarchs’ life cycle and other facts about them. Volunteers have created a website about the sanctuary, at www.monarchdunesbutterflies.org.
“Who doesn’t love monarch butterflies?” asked Judy Richards, chairwoman of the Monarch Butterfly Habitat Volunteer Committee. “Kids particularly love them.”
Everything about the site is designed with monarchs in mind. The trees are maintained at various heights to give the butterflies a variety of places to roost.
A walkway winds through the grove. It is bordered by grass and flowering plants including giant coreopsis, a plant native to sand dunes. These plants provide water and nectar for the butterflies, a crucial resource during their stay.
“This is the epitome of all the monarch projects I’d like to achieve,” Leong said.
All this work and loving attention is paying off. During the winter of 2005-06, only 50 butterflies roosted in the site. The Nipomo sanctuary now regularly attracts 10,000 each year.
Sanctuaries such as the one at Trilogy are successful because they are community efforts, Leong said. The Monarch Grove Natural Area, at the end of Monarch Lane in Los Osos, is another example of a successful cooperative effort.
That 18-acre site is managed by County Parks. A group of five volunteers has a modest endowment of $50,000 to manage the grove, which this year hosted about 620 butterflies.
They recently got a helping hand from Cal Fire. The agency was scheduled to thin the stand to reduce the fire danger to nearby homes. Leong arranged to have foresters with the agency also create a clearing in the middle and do other work to entice monarchs to the grove.
“When we modified the grove, the butterflies came right away,” Leong said. “Cal Fire, County Parks and the community all worked together to benefit the grove.”
Like all monarch butterfly enthusiasts, Leong is concerned about the long-term viability of the species. Biologists estimate that the monarch butterfly population in the western United States is about a tenth the size it was a century ago.
This is because during the summer, monarchs lay their eggs on milkweed plants, and the butterflies in their larval stage feed on the plant. The loss of milkweed to development and agriculture is the reason for the reduction in the monarch population, Leong said.
“The summer range is the key to the monarch’s survival,” he said.
Leong likens his work on establishing and enhancing monarch wintering habitat along the Central Coast to creating a winter resort for them. He cannot control how many monarchs migrate to San Luis Obispo County, but he can work to provide a maximum amount of suitable habitat for them once they are here.
Monarchs have survived other significant changes in their environment during the past century, including wholesale replacement of Monterey pines with non-native eucalyptus trees throughout their wintering range.
“The story of monarch butterflies is one of adaptation,” Leong said.
THREE MONARCH BUTTERFLY PRESERVES
The three monarch butterfly preserves established by retired Cal Poly biology professor Dr. Kingston Leong can be found at these locations:
Monarch Dunes Butterfly Habitat in Nipomo: The eucalyptus grove is on Kingston Drive in the Trilogy at Monarch Dunes development.
Monarch Grove Natural Area in Los Osos: In the Monarch Grove development. The eucalyptus grove is at the end of Monarch Lane off Pecho Valley Road.
Morro Bay Golf Course: 201 State Park Road in Morro Bay. The eucalyptus grove is in the center of the golf course.