Scientific Name: Danaus plexippus
See the Monarchs
- How many monarchs are in Pacific Grove and Monterey County right now?
- Where can I see monarchs in Monterey County? How much does it cost and is it ADA accessible?
- When is the best time of day to see the monarchs?
- How can I view the monarchs in a way that is safe for the monarchs?
- Where can I see monarchs in Santa Cruz and San Luis Obispo Counties?
- When is the best time of year to see the monarchs?
- I know that the monarch migration is endangered. How can I help?
Curious Monarch Science
When is the best time of year to see the monarchs
You can begin to see monarchs cluster in Central Coast overwintering sites beginning in November. The monarch population peaks in size at the end of November to early December. Monarch mating season is in February around Valentine's day. The monarchs leave the California Central Coast around late February to the end of March.
The Museum's Monarchs Come Home exhibition is open year-round. Highlights of this exhibition include real specimens, amazing videos, vintage artifacts, a "cabinet of curiosities," and multiple hands-on opportunities--all wrapped in the most up-to-date scientific knowledge and artistic presentation.
Where can I view monarchs in Monterey County? How much does it cost and is it ADA accessible?
Pacific Grove has one of the largest monarch overwintering sites in America and the largest population of overwintering monarchs in Monterey County for public viewing. Pacific Grove is a minute drive from the Monterey Bay Aquarium and minutes from Carmel-by-the-Sea.
The Monarch Sanctuary is located at 250 Ridge Road off of Lighthouse Avenue in beautiful downtown historic Pacific Grove and just 10 blocks from the Museum. Parking on Ridge Road is free. The sanctuary is maybe one block from the parking and it is ADA accessible.
The sanctuary is a Pacific Grove municipal park and is freely open from sunrise to sunset. There is no admission fee. Donations to support the Museum monarch education and the monarch docent programs are deeply appreciated.
Where can I see monarchs in Santa Cruz and San Luis Obispo Counties?
Look to Natural Bridges State Park for monarch viewing in Santa Cruz County. We strongly recommend calling the park prior to your visit 831-423-4609. Sometimes the Santa Cruz monarch population can congregate at a Lighthouse Field State Park and the park rangers will be able to give you the most accurate and timely viewing information.
The Pismo Beach Monarch Butterfly Grove is the largest public viewing of monarchs in San Luis Obispo County and is also one of the largest monarch overwintering sites in America. This sanctuary has a docent trailer on site open from 10 am to 4 pm with docent talks held everyday at 11 am and 2 pm.
When is the best time of day to see the monarchs?
Monarchs can't fly when the temperature is below 55 degrees so if you visit in the morning when the temperature is cold, you may not be able to find them. There are many trees in overwintering sites and when clustered high in the trees, monarchs can look like dead leaves and most untrained eyes will be unable to find them.
Museum docents are present everyday in Pacific Grove's Monarch Sanctuary from Nov to Feb from 12-3 (weather permitting). Our docents significantly enhance your viewing experience with viewing scopes and their ability to answer your questions. Our docents are present from 12-3 because this is the warmest time of day and you will see both clustering behavior and monarchs flying around. It's beautiful.
How many monarchs are in Pacific Grove and Monterey County right now?
The monarchs are just starting to return. This warm October weather means they can mainly be seen flying rather than clustering. More and more arrive every day!
There are currently 3,200 monarch butterflies in the Pacific Grove Monarch Sanctuary (monarchs counted October 22, 2014). The population peaks at the end of November/beginning of December with mating season occurring around mid-February.
The Museum monarch docents are available to assist with monarch viewing every Saturday and Sunday, 12-3 through October and everyday beginning in November.
Monarch counting at the other Monterey County overwintering sites begin in mid-November.
How can I view the monarchs in a way that is safe for the monarchs?
Please take note of monarch viewing etiquette for the betterment of the monarchs, sanctuary neighbors, and the other people enjoying the sanctuary.
- Please stay on the paths. Monarchs often drink their water from the fog dew left on the ground. You could step on a monarch and never know it.
- Dogs are not allowed in the Monarch Grove Sanctuary. (City ordinance 14.8.030)
- Please be quiet out of respect to those living in neighboring houses, staying in hotel rooms around the sanctuary, and enjoying their own monarch viewing experience.
- Do not touch or pick up the monarchs. The Pacific Grove Police Department continues to enforce strict regulations that prohibit the "molestation of butterflies." The fine? $1,000.
- Be careful around newly planted trees, flowers, and shrubs. The City of Pacific Grove manages the sanctuary grounds and often has new plantings to strengthen the habitat.
- Leave only footprints on the paths; take away only photographs and great memories!
I know that the monarch migration is endangered. How do I help the monarchs?
If you live along the California coast, plant nectar plants to support the monarchs migrating to overwintering sites. If you live inland, PLEASE plant nectar plants AND MILKWEED to support the monarch migration away from the overwintering sites.
Milkweed is the only plant a monarch can lay its eggs on. Fragmented milkweed corridors is of concern to scientists studying why the monarch population is in decline. By planting milkweed over one mile from monarch overwintering sites you are encouraging their healthy migration.
Curious Monarch Science
How do the monarchs return to the overwintering sites each year?
The Monarch Butterfly (Danaus plexippus) is a widespread tropical insect that ranges as far north as Canada. It cannot withstand freezing winter temperatures. To survive, monarchs migrate to safe overwintering sites that are neither cold enough to kill it, nor so warm that it wastes precious energy flying too much.
Monarchs east of the Rocky Mountains spend the winters in high mountains in central Mexico. Monarchs west of the Rockies migrate to locations on the California Central Coast. En route, they may travel as far as 2,000 miles, covering one hundred miles per day, and flying as high as 10,000 feet. A mighty achievement for such a seemingly fragile insect!
Why is this migration so unique? In many migrating species, such as birds and whales, the same individuals travel the migration route year after year. In contrast, migrating monarchs have never been to their destination before. In fact, several generations of Monarchs have lived and died since last year's butterflies departed. Reduced daylight triggers the monarchs to hold off mating and migrate to survive the drop in temperatures. It is believed that delaying mating enables the monarchs to live longer to accommodate the migration. Adult monarchs can live up to 6 weeks, but the migrating adult monarchs can live up to 6 months. No one knows how the monarchs migrate to the same places each year.
How do monarchs smell, taste, and hear?
Monarchs smell with their antennae and taste with their feet. Hearing is very different with monarchs. They certainly do not hear sound as we do. They respond to air vibrations and hear ultrasound.
How many eggs can one monarch lay?
During her lifespan, a female Monarch may lay hundreds of eggs. She deposits pin-head sized eggs on the underside of milkweed leaves, where they will hatch in 4-5 days, depending on the temperature. The newly hatched larva feeds voraciously on the milkweed, accumulating bitter chemicals from the host plant which help protect the Monarch from birds. Over the next few weeks, the caterpillar grows from 1/16th of an inch to about 2 inches in length, increasing its weight by a factor of 2,700. To accommodate this rapid growth, the caterpillar must shed its distinctively striped skin several times before it is ready for the next stage of its development; a chrysalis.
The truth about milkweed.
The only plant a monarch can lay eggs on is a milkweed. Planting milkweed and nectar plants are both great ways to support healthy monarch populations. Our Museum recommends planting milkweed over one mile from monarch overwintering habitats which includes all inland valley areas. This encourages monarchs to begin their migration to lay their eggs. Nectar plants support the migrations to and from overwintering sites and should be planted everywhere.
What's the difference between a chrysalis and a cocoon?
A caterpillar sheds its skin many times to grow. A chrysalis is the final hardening of the caterpillar's outer skin before it begins to change into a butterfly. Moths spin cocoons around their chrysalis for added protection during metamorphosis. Butterflies do not. Instead you see the beautiful exposed chrysalis until the butterfly emerges as an adult. Every butterfly chrysalis is distinctly different in appearance.
The fully-grown monarch caterpillar usually leaves the milkweed to seek out a bare branch or similar sturdy surface. It attaches itself by spinning a silk button from which it hangs upside down in the shape of the letter "j". After settling down, the caterpillar sheds its skin a final time, revealing a beautiful green chrysalis decorated with delicate gold spots. Inside the chrysalis, the caterpillar's body is undergoing metamorphosis, the process by which its tissues and organs rearrange into the startling different body of a Monarch butterfly. After two weeks, the chrysalis becomes transparent, signaling that the black and orange butterfly within is ready to emerge.
What's the first thing that a monarch does when it emerges from its chrysalis?
When ready, the monarch chrysalis splits open along several joints, and the Monarch butterfly carefully emerges. Its wings are still folded and crumpled from confinement in the chrysalis, so the butterfly must pump fluid from its body into the wings, expanding them quickly to full size. The monarch must also assemble its proboscis, a straw-like tongue by which the monarch drinks nectar, which is in two pieces when it first emerges from the chrysalis. A female monarch has approximately 6 weeks to seek out nectar, mate, and lay eggs before she dies.