Tracking the Monarchs’ Secret

The people of the Pacific Coast states are being recruited in a voluntary hunt that may open up the secret of the extraordinary migration of the monarch butterflies, Danaus plexippus --those brilliant orange-and-black creatures that, for the moment, are congregated along the coast but presently will be heading toward inland valleys and mountains.

Chris Nagano, research associate at the Los Angeles County Natural History Museum, has been busy leading a team that is putting conspicuous numbered tags on the right forewings of about 35,000 of the butterflies at their over-wintering spots from Mendocino south to Ensenada. These tagged monarchs will start moving to inland areas in February. But where? That is where you come in. You are asked to join the hunt. If you spot a live monarch with one of the tags, get close enough to read the number on its wing and report that and the location and date to Nagano. If you find a dead monarch with a tag, mail the butterfly, along with the date and location, to him. He operates out of the museum at 900 Exposition Blvd., Los Angeles 90007.

The hunt will be over in April or May, when this generation of butterflies lays its eggs on milkweed plants and dies. Another couple of generations will repeat the egg-caterpillar-chrysalis-butterfly cycle before the autumn migration back to the West Coast or, in the case of the Eastern states, the migration south to Mexico. Those making the long westbound flights--this is the amazing part of it--navigate unerringly but, as Nagano reminded us, “they have never been there before.” They are the great-grandchildren of those that made the first leg of the eastward trip earlier in the same year.

The biggest concentration this winter is on private land in Santa Barbara County that is not accessible to the public. At Pismo State Beach, however, there is a major group, and docents are on duty to guide visitors to the site.

Tagging of the butterflies is not new, but it is much expanded. Its value was demonstrated a few years ago when a woman in Morro Bay found a monarch that had been tagged by a Canadian team in Boise, Ida. It was a flight of more than 600 miles for those fragile wings.