Delta Pond GPH Update
For the third year running, we've looked for Great Purple Hairstreaks on the solitary Baccharis in the meadow at the toe of Delta Pond. There are other possible GPH targets nearby, like Goldenrod, Devil's Beggartick, and Tall Peppergrass; but all summer these have come and gone without any butterflies that I saw. By the end of September we get the bloom on the Coyote Brush and our best chance of seeing some.
Brian Webb is at this site most days. He watched the slowish blooming of the huge plant, and finally saw the first butterfly feeding on 9/28, a Grey Hairstreak. By the next day, the GPH were back. Looking at the raft of texts he sent me up until Halloween, I see images of possibly 20 individuals; even one with 3 of these scarce beauties in a single frame. I went six times between 10/2 and 10/29, usually 12 to 2 PM, and saw a few of these each time. Last year's sightings were earlier(9/23), and these seemed to peter out by 10/1. This year, we had an unusual opportunity to watch them for an entire month. Cool rain on 11/1 seemed to draw the curtain, with the bush going to seed.
The strong showing of GPH this year was an exception in this drought year, especially in an area where Water Dept. crews have scoured off much of the surviving bloom. Last year there were hundreds of Grey Hairstreaks, Mylitta Crescents, several sorts of Skipper; this year barely a handful. A consolation was the strong showing of Purplish Coppers, nice Rosa-form Buckeyes, and at least three sightings of Pygmy Blue-- I believe this last a first for the Laguna.
It's still unknown where the GPH roost. An obvious home base would be the Mistletoes in the adjacent creek willows; although there's lots of Oak and another type of Mistletoe within a mile. I've tried to see these butterflies head off to these tree tops, but they prove rather difficult to observe in flight.
I'm thinking is that one of their great tricks is to fly as little as possible. This spot teems with insectivorous avians, so that seems the safest way. Certainly many of these GPH show heavy bird damage, often with all of their hindwing 'false head' structures neatly snipped off. The insects we watched spent hours on the bush each visit, systematically clambering up and down branches visiting hundreds of flowers. A good part of this time would be spent 'inside' the plant nectaring in the shade, barely visible as a matte-black rectangle. Occasionally they'd fly in very short hops to a nearby branch sometimes with a tiny flash of blue.
Frequently they are lost even to the careful watcher, even knowing their position to within a few inches. So obvious on Rabbitbrush or Goldenrod, here the Baccharis provides a cloak of invisibility.
They are well-designed for this lifestyle. A typical lycanid is a skinny animal with feeble, threadlike legs; while the GPH is a fireplug of a butterfly, stepping out on sturdy pins worthy of a brushfoot or swallowtail. Once landed on the Baccharis, even the individuals with severe wing damage are fully competent and entirely at home. Larval GPH , dozing in the Mistletoe, probably dream of climbing...
This season I was hoping to find new sites in Sonoma County, with no joy so far. But, after the pleasure of watching these standout butterflies disappear into this Baccharis, only occasionally stepping out for my lens, I've a new perspective. Even down from the treetops, these are too easy to miss. This will take a while.
My strategy will be to focus on spots with more than one sighting. Nearby, Ragel Ranch Park has two sightings, a huge amount of willow mistletoe and nice goldenrod. This looks like a best bet. There have been at least two seen at the Hallberg Butterfly Garden, so we could hope for more. Baccharis seems to
be a key, so everywhere I see it in full bloom I will be attentive, hoping to catch a twinkle of deep blue.
