Monarchs in New Zealand

[Paul Cherubini]

Pierre A Plauzoles wrote: 

> Here in North America, the Monarch (Danaus plexippus) will do well
> only on milkweed (Asclepias sp), the problem being predation on the
> adults (that have fed on certain plants other than milkweed) by
> certain birds. 

Monarchs that feed on milkweed sometimes get attacked by birds.
Lincoln Brower and his co-workers estimate birds kill and eat parts of
15,000-30,000 monarchs PER DAY at the overwintering sites in Mexico.
His research also shows that 92% of the monarchs overwintering in Mexico
fed on Asclepias syriaca as larvae. 

David Marriott, director of the Monarch Program in San Diego, Calif.
has watched and photographed kingbirds catching and eating one monarch
after another over a period of a month at the overwintering site at Camp Pendleton
in Oceanside, Calif. Nearly the whole overwintering colony was 
devoured there in Oct. 1997 & Oct. 1998. 

Other monarch biologists in California such as Walter Sakai and John Dayton
have recorded numerous observations of bird predation at the overwintering
colonies along the Malibu coast, in Santa Barbara and Santa Cruz. In the western 
USA, no one I know has ever seen monarch caterpillars feeding on any plant in the wild 
except Asclepias spp. - never geraniums.

Paul Cherubini, Placerville, Calif.