Butterflies and Sirens
(A response to the sudden migration of Painted Lady Butterflies to Los Angeles, spring of 2019)
I was there for the rain,
but left
before the early bloom
of nettles and mallows,
was absent
when the angel voiced siren of Los Angeles
taunted the Painted Ladies north
to feast on lupines and milk weed,
everywhere
the cloak of orange,
their black wing-tipped eyes,
staring down at the amazed denizens,
while skimming by buildings,
and bike racks, and bus horns blazing
hundreds in mid-day light,
hovering, while the sirens of the city,
blared through this place of comings and goings
drawing all to look closer,
at the shock of arrival,
the surprise of flight,
and a noon epiphany--
the sirens' calls--
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--Paul Chambers
Vanessa cardui (formerly known in North America as the cosmopolitan) resides only in warmer areas but migrates in spring and sometimes again in autumn. Since the autumnal migrations are conducted at high altitude, they are seldom witnessed. Their migration patterns are highly erratic, and they do not migrate every year. In California, the migrations appear to be partially initiated by heavy winter rains in the desert, where rainfall controls the growth of larval food plants; heavier-than-usual rain in the 2018-2019 winter seems to have caused an extraordinarily large migration. The migratory pattern is probably the cause of the species' unique system of continuous mating, throughout all seasons. They begin to breed during the migratory process and reproduce entirely throughout the migration. Female painted lady butterflies may suspend their flight temporarily when they are ready to oviposit, allowing them the opportunity to continually reproduce throughout their migration. Because they are constantly migrating, male butterflies lack consistent territory, so instead of requiring territory to mate with females and developing evolutionary behavior to defend it, the mating butterflies appear to establish a particular time and place in certain locations that they find to be suitable for reproduction. More specifically, they locate certain perches, hilltops, forest-meadow edges, or other landmarks where they will stay until a female arrives to mate. In addition, the males often mate with more than one female. Upon mating, which typically occurs in the afternoon, female painted lady butterflies lay eggs one by one in their desired breeding locations, and they each produce large numbers of offspring. Their reproductive success declines relatively throughout the winter, primarily through November, but they continue to reproduce —- a unique aspect of butterfly behavior.
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