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Monarch Butterfly

Monarch Butterfly
Monarch Butterfly - Danaus plexippus

Monarch Butterflies
Monarch Butterflies winter roost, Natural Bridges State Park, Santa Cruz

Monarch Butterfly Migration Routes


The North American Monarch butterfly is the only insect known to make an annual, long distance migration. Monarchs west of the Rockies migrate to the California coast in winter. They usually arrive in late August and September. initially gathering in "bivouac sites" for a few days to a few months - depending on the weather. They move to their over-wintering sites, from October to February, with the onset of colder weather.

For more information see the Butterflies page and for other insects see the Insects section.

Monarch Watching Locations

>> Natural Bridges State Beach, Santa Cruz
They get over 100,000 Monarchs each winter. Monarchs begin arriving in October and most are gone by the first week of March.There is a demonstration milkweed patch where visitors may view Monarch eggs, caterpillars and chrysalides.
>> Monarch Grove Sanctuary, Pacific Grove
Always open, admission is free. 
>> Pismo Beach Grove
They have had an average Monarch count of over 25,000 over the last 5 years. The butterflies are here usually from November to February. It is located on Highway 1, just south of the Pismo Beach North Beach Campground.
>> Ardenwood Regional Preserve, Fremont
Ardenwood has up to 2000 butterflies in a good year. You can take a short hike to see overwintering Monarchs in Ardenwood's eucalyptus forest. 
>> Monarch Bay Golf Course and Marina, San Leandro
Check for tours that are offered every Saturday. .

Articles/Links about Monarch Butterflies

Monarch Butterfly Watching Information

  • Monarchs in Monterey County - a very comprehensive website sponsored by the Ventana Wildlife Society. 
  • Article on Monarch Butterflies in the Golden Gate National Recreation Area by the National Park Service. Mentions Fort Mason, the Marin Headlands, Tennessee Valley, Muir Beach, and Stinson Beach as wintering sites. 
  • Where to see Monarchs in Big Sur area, also includes good general information about Monarch Butterflies. 
  • Where You Can See Overwintering Monarchs in California - a fairly comprehensive page from the Xerces Society. 

General Information about Monarch Butterflies

  • Science on the SPOT: Monarch Meetup, KQED Quest article and video, 5 April, 2012. About Monarch over-wintering requirements and migration. 
  • Migration or Expansion, Monarch Butterflies Make Us Aflutter by Ron Sullivan and Joe Eaton, on, 12 December, 2007. Article touches on theories about Monarch migration in the West. 
  • There is a fantastic PBS/Nova television program about Monarch migration - The Incredible Journey of the Butterflies. It was first aired in January 2009. You can buy a DVD or even watch it online at this website. 
  • Journey North has a great section about Monarch migration with maps, current news and ways for students to participate. 
  • Western Monarch Thanksgiving Count 
  • Monarchs in California - lots of information about Monarch Butterflies and their conservation. 
  • Biology, range and other details from Butterflies and Moths of North America website. 


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