Monday, April 25, 2011
Everybody Loves a Butterfly
There are lots of mourning cloak butterflies (Nymphalis antiopa) in flight these days. Yesterday I observed one of them for awhile visiting the back garden.
It would enter the garden space by sailing over the back neighbor's bougainvillea, or the side neighbor's tecomara, or by shooting the channel between our ligustrum hedge and the cedar fence. Then it would land on a sun-lit shrub, often the tallest phlomis but also the tip of an artichoke leaf or sometimes a bare lemon verbena stem or the eriogonum and even the privet.
Occasionally the butterfly would flex its wings downward past the horizontal into the ventral hemisphere; it looked like it was hugging the stem it was on, or hunkering down. But mostly it perched with wings together, slowly opening them from time to time. Then it would fly off, circle the yard and land again; and again and again.
These butterflies feed on tree sap as well as nectar; I saw one feeding on a pittosporum leaf that was sapping due to psyllid infestation. So its possible some feeding or foraging is involved with all this shrub-perching. But I suspect it's more likely to be a male territorial/mate-finding behavior with the high perches serving as a good vantage point for the overhead airspace, and the frequent fly-arounds a way to check for and discourage competitors from entering its territory.