San Francisco – Everyday Insider (TM) Trip 22C

On San Francisco’s famed 49 Mile Drive, Twin Peaks, a fabulous natural area in the heart of San Francisco, not only gives visitors amazing 360 degree views, weather permitting, but also offers a refuge for the endangered Mission Blue Butterfly, which you may see if you are lucky.

The Mission Blue butterfly is a federally listed endangered species which still survives in a few, small areas of San Francisco, Marin, and San Mateo counties. Silver lupine is one of three native lupine species which provide habitat during different stages of this fascinating butterfly’s life-cycle.

The lupines are: Lupinus albifrons, Lupinus formosus, and Lupinus variicolor – silver lupine, summer lupine and the varied lupine. These plants need to be protected, as without them, the butterfly cannot survive.

The 3 native lupine plant species provide very specific, necessary food and shelter for the butterfly in its larval stage. Part of the conservation strategy is to help the plants revive, to reclaim their native areas, by helping to remove invasive, non-native species.

Once an adult, the Mission Blue is no longer completely dependent on the lupines for survival. It drinks the nectar of a variety of flowers, many are in the sunflower family. It uses its long proboscis, which extends from the underside of its head.

Twin Peaks is a major ecological ark for the butterfly. Please make sure you are careful nearby, if you see one. It may be laying eggs or needing to feed. Please stay on the trails, only.

There’s a fascinating waltz and drama going on before your eyes. The female butterfly lays eggs on the silver lupine and then feeds on its nectar.

When the butterfly eggs hatch in 6 – 10 days, the newly emerged caterpillar then feeds on the inner parts of the lupine leaves. Once the caterpillar obtains enough food energy for the winter, it inches its way down to the base of the plant and then goes dormant.

The next spring the caterpillar will emerge, feed again and then return to the ground to pupate.

Soon it emerges from its cocoon and chrysalis, as a butterfly.

Like many butterfly species, Mission Blue’s larvae have a mutualistic, symbiotic relationship with ants.

Caretaker ants actually stroke the larvae with their antennae, which causes the larvae to secrete a sugary fluid, called “honeydew”. The ants crave this. In return for this sugary food, the ants protect the larvae from predators and parasites, but about 33% of the larvae are still lost to these sources.

The butterfly is unmistakable. It is a subspecies of Boisduval’s blue,
and the endangered Mission Blue has a wingspan of about 21–33 millimetres (0.83–1.3 in). Its larvae are extremely small and rarely seen.

The males’ top wing has phenomenal color gradation — from ice blue in the center to deep sky blue. This is not properly captured by cameras. Its iridescence is amazing. The wing color carries no hint of green or purple, strictly capturing a spectrum of purest, clearest, richest, brightest blue. There is a dazzling iridescent fluctuation under direct, full sunlight.

Black margins on the upper wing sport “long, white scales.” Then, a notice a constellation of jet-black dots complimenting the wing shape. The colors are in spectacular contrast against the shimmering silvery pearlescent lupine background.

As is usual in Nature, the female’s colors are quiet, so she can be protected and hide more easily.The females’ upper wings are dark brown, but otherwise mirror males in their size and shape.

As I have said, P. i. missionensis is federally endangered and found in only a few locations anywhere in the world.

Its habitat is restricted to the San Francisco Bay Area, specifically to six areas:
___ Twin Peaks area in San Francisco County
___ Fort Baker, in Marin County, a former military installation part of the National Park Service (NPS)
___ San Bruno Mountain area in San Mateo County
___ Marin Headlands, in Golden Gate National Recreation Area (another National Park Service site)
___ Laurelwood Park & Sugarloaf Open Space in the city of San Mateo — where my family used to live, right next to Sugarloaf. My family actively fought to protect the whole mountain from developers in the 1960s and 1970s.

It is now the only Open Space in that part of the County. I am so proud that we fought so long and hard and succeeded. Our own backyard was hilly, leading down to Laurelwood Creek and it was left entirely natural by us; I hope the new homeowners did the same. We are stewards of the land, and our decisions selfish or not, short-term or long-term, make huge impact on the land.

___ Skyline Ridge, also in San Mateo County, an area I visit as my father is buried, high on the hills. It is also beautiful, natural, untouched space where the Mission Blue has a chance to survive, away from crowds of humans.

San Bruno Mountain hosts the largest population of Mission Blues, a butterfly that is commonly found at elevations of 700 feet. The San Mateo County colonies have been located at elevations of 690 – 1,180 ft. Some colonies have also been found in the “fog belt” of the coastal mountain range, where the Mission Blue colonies in the area prefer coastal chaparral and coastal grassland biomes.

The Mission Blue butterfly was first collected in the Mission District of San Francisco in 1937, near the Twin Peaks colony. Only one generation is born per year.

The butterfly can be sighted as early as late March in places like the summit of San Bruno Mountain or on Twin Peaks. The Mission Blues persist well into June, when they will be seen perched on a lupine plant or feeding on coastal buckwheat flowers.

In butterfly form, the adult Mission Blue lives approximately one week!

During this time, the females lay the eggs on the host plant. That is why it is SO important to be careful and keep a respectful distance, along with protecting the plants. We are all that stands between life and extinction. Help where you can.

More about Twin Peaks, next time.

San Francisco Archive

©2010 mystic at Travel Vacation Review

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