Monarchs are Migrating in Mount Washington
Location: Mount Washington, Los Angeles, California
November 11, 2013
Yesterday while helping our friend Lisa Anne determine which plants should stay and which should be removed from her newly purchased Mount Washington home, we noticed two Monarchs flying through her yard and over Elyria Canyon Park. This morning while running errands, we noticed four more Monarchs. We suspect the Monarchs are seeking wintering grounds either to the north or to the south in Mexico, and they are passing through Los Angeles to get there. We need to do some gardening today, but we will provide an update with a new photo if any Monarchs alight on the lantana or the zinnias currently blooming in the garden.
Ed. Note: We contacted our neighbor, Julian Donahue, about the migration and we had a nice chat on the phone regarding migration and tagging of butterflies. We mentioned that many of our readers raise Monarchs and tag them so that they know which butterflies they raised, including Dori Eldridge from Naperville, Illinois. We thought we had an old posting where green paint was used to mark a Monarch, which Julian discouraged as color blind individuals cannot see red or green. Julian provided us with a photo of a tagged Monarch as well as some additional information on migrating butterflies. If you encounter a tagged Monarch, please report it using the website provided on the tag.
Daniel, you and I discussed the Monarchs and Painted Ladies on the phone: the former are drifting around (natives and possible migrants arriving for the winter), while the Ladies are residents–they don’t migrate until around April, if at all. I’ll be posting a notice about Monarchs that were tagged in Washington state on the LepSoc Facebook page.
I’m attaching the photo I promised of a tagged Monarch from Washington, which has on it the e-mail address to report sightings or recoveries.
Julian
Daniel will forgive me if I offer a little clarification about Monarch overwintering sites on the West Coast. A fascinating and informative paper by John Lane, 1993 (“Overwintering Monarch Butterflies in California: Past and Present”), in Biology and Conservation of the Monarch Butterfly (Natural History Museum of Los Angeles County, Science Series No. 38, pp. 335-344) summarized our knowledge about where western Monarchs spend the winter. Just over 200 overwintering sites have been reported in California, from Mendocino to San Diego Counties (about 80% of the California coast), with one overwintering site reported in Ensenada, Baja California (the only site known in western Mexico). (There are isolated inland observations from Kern and Inyo Counties, California.) Although I am not aware of any overwintering sites on the California Channel Islands, two Monarchs tagged at the overwintering site in Leo Carillo State Beach, Los Angeles Co., on 26 Dec. 1985 were recovered during the spring dispersal from that site on Santa Cruz Island, Santa Barbara Co., on 5 February 1986 (“Spring Migration of Monarch Butterflies in California” by C.D. Nagano et al., pp. 219-232 in the same volume).
Since Monarchs reproduce in, and adults are found year-round in, at least Orange and Los Angeles Counties in southern California, the butterflies we see here in November and through the winter may be a mixture of residents and migrants–there is no way to distinguish between them in the field–unless the Monarch has been tagged! (Chemical analysis of a specimen, however, could determine which species of milkweed the butterfly fed upon as a caterpillar, thus identifying the butterfly’s origin within the distribution of that particular species of milkweed. The results of such an analysis may not be conclusive, however, because many milkweeds are cultivated for ornamental purposes outside their normal range, especially the tropical Asclepias curassavica here in Southern California.)
Thanks so much for this thorough explanation Julian.