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Thursday, May 31, 2012

Enjoying the Gilia

 Blue Coast Gilia (Gilia capitata subsp. chamissonis) 


A native annual that grows in older, stabilized dunes.  Here's a close-up. 


Check out the exserted stamens (protruding beyond the petals).  A stamen is a male reproductive part, consisting of an anther (the part that produces the pollen) and a filament (the stalk that supports the anther).  In the photo above, the anthers are the light blue football-shaped structures and the filaments are the slender purple stalks below them.

The spherical heads of Blue Coast Gilia are made up of 25-100 flowers.  Before they start blooming, the buds look a bit like a fuzzy blackberry.

 
I wasn't the only one enjoying the Gilia today!


Wednesday, May 30, 2012

Reversal

On 9 May 2012, I posted a few photographs of a female Red-necked Phalarope at Van Damme State Park near Mendocino.  On 26 May 2012, we encountered a male in a small pond in the Bodega Dunes (see below).



There is reverse sexual dimorphism in phalaropes — females are more brightly colored than males.  If you compare the photos, look for the following:

- head coloration is more uniform and darker gray in females; it has a browner tone in males

- the white spot above the eyes is brighter and more distinct in females; it is duller and blends into a supercilium (eyebrow) connected to the red hindneck patch in males

- the red hindneck patch wraps around in front of the neck/breast in females; it's less extensive and more amber-colored in males 


For comparison, here's the female:


In phalaropes, sexual roles are also reversed.  Male phalaropes provide all parental care.  The male incubates the eggs and broods the chicks, while the female rarely visits the nest after the last egg is laid.

Tuesday, May 29, 2012

Connectivity

This morning there was an article in the San Francisco Chronicle describing a research paper that found Cesium-137 from the Fukushima Dai-ichi nuclear disaster in Pacific Bluefin Tuna (Thunnus orientalis) off the California coast. 

Adult Pacific Bluefin Tuna spawn in the western Pacific off Japan, then juveniles migrate to the eastern Pacific off California.  Scientists sampled muscle tissue from bluefin tuna caught near San Diego in August 2011 (three months after the earthquake and tsunami).  They found Cesium-137 levels ten times higher than in previous years.  (Note that although elevated, these levels were far below the safety limits for human consumption.)

Although I have yet to see a Pacific Bluefin Tuna, they occur off the central California coast, especially in fall.

Here's a photo of me with an Atlantic Bluefin Tuna (Thunnus thynnus) on South Monomoy Island in Chatham, MA,  in 1993.



In March, Claudia sent me an article about radioactive kelp.  Researchers sampled Giant Kelp (Macrocystis pyrifera) in southern and central California in April 2011, one month after the nuclear accident.  They found elevated levels of Iodine-131 (radioiodine).  In this case, the Iodine-131 was released into the atmosphere and then deposited in surface waters with precipitation.  (Kelps accumulate iodine and store it as iodide which functions as an antioxidant.)  Four weeks after the initial collection and measurement, Iodine-131 was no longer detectable.

Giant Kelp grows near the entrance to Bodega Harbor and also washes up as drift algae on local beaches.  Here are a few photos (taken along the Big Sur and Monterey coasts).


The presence of radioactivity from a nuclear disaster in Japan in animals and algae off the California coast is testament to connectivity across the entire Pacific Ocean basin.  


Madigan, D.J., Z. Baumann, and N.S. Fisher.  2012.  Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California.  PNAS Early Edition, 29 May 2012: 1-4.

Manley, S.L. and C. Lowe.  2012.  Canopy-forming kelps as California’s coastal dosimeter: Iodine-131 from damaged Japanese reactor measured in Macrocystis pyrifera.  Environmental Science and Technology 46: 3731-3736.

Monday, May 28, 2012

Gray-blue eyes


A beautiful male California Darner (Rhionaeschna californica) perched on a horsetail (Equisetum sp.) along Bay Flat Road at the north end of Bodega Harbor on 25 May 2012.

Note the gray-blue eyes and the very thin, faint stripes on top of the thorax (they're barely visible).  The thorax is the brown surface directly behind the eyes.  These field marks separate this species from the similar Blue-eyed Darner (Rhionaeschna multicolor) known for its brighter blue eyes and stronger blue thoracic stripes.


California Darners occur from British Columbia to Baja California.  Their spring flight season is unusual among the neotropical darners (Rhionaeschna spp.) and mosaic darners (Aeshna spp.).  They're on the wing as early as February.  Many of the other large blue darners fly during the latter half of the summer. 

This species is ~5.5-6 cm (2-2.5") long with a wing span of ~8-8.5 cm (3-3.5").  Watch for them chasing small insects in areas sheltered from the wind.

Sunday, May 27, 2012

Along the Coast Trail


We walked the Coast Trail at Point Reyes from Palomarin to Alamere Falls today.  Below are a few of my favorite images from the day.  

I believe there are records for all three of these species on Bodega Head. 

Wilson's Warbler (Cardellina pusilla)

Today we noticed several Wilson's Warblers gathering food, probably to feed their young.  It looks like the individual above (same bird in both photos) has a caterpillar and several flying insects.

A study in Marin County found that the number of feeding visits increases through the nestling period, e.g., on day 1 = 1.1 visits per nestling per hour; on day 3 = 3.3 visits per nestling per hour; and on days 5-8 = 12-15 visits per nestling per hour!  [Average brood size or number of nestlings is four.  Wilson's Warblers fledge (the young leave the nest) in about 10 days.]


Satyr Anglewing (Polygonia satyrus)

The Butterflies of Canada (Layberry et al. 1998) states that Satyr Anglewings "should be looked for in clearings in wooded areas with streams nearby where Stinging Nettle can be found."  This is exactly where we encountered this individual today.  (The nettles are the host plant for their caterpillars.)


Sonoma Chipmunk (Neotamias sonomae)

Some of you might laugh, but we were thrilled to see a chipmunk today.  We don't get to see them on Bodega Head, as they prefer forested areas (which Bodega Head lacks).  Eric observed this chipmunk with a bright red berry (about the size of a cranberry), but we're not sure what it was.

If I remember right, there might be a record for Sonoma Chipmunk on Bodega Head, but I'll have to follow up on that record.
 

Saturday, May 26, 2012

The richest amethyst

Several views of the same individual male Anna's Hummingbird (Calypte anna) — photographed across from Westside Park on 25 May 2012.

  
Because the color is dependent on the microscopic structure of the feathers and the refraction of light, it changes with the viewing angle.


From The Birds of North America account by Clark & Russell (2012):

Lesson regarded it as one of the most beautiful hummingbirds, on account of “the bright sparkle of a red cap of the richest amethyst...” on the male’s head, and so named it after the duchess of Rivoli, Anna de Belle Masséna. Gould (1861) placed it in a new genus, Calypte, for “not only the throat, but the entire head as glitteringly resplendent as if they had been dipped in molten metal”.



Thursday, May 24, 2012

Sisyrinchium and the Scotsman

 Yellow-eyed Grass (Sisyrinchium californicum)


A beautiful perennial herb in the Iris Family.  Yellow-eyed Grass grows in moist habitats along the coast from central California north to British Columbia.

The yellow flowers are ~3 cm across.  Note the distinct lines running parallel to the edges of the petals. 


Seeds are contained within brown capsules.


 A flower just before opening.



I think I'll always associate Yellow-eyed Grass with Archibald Menzies.  Menzies (a Scottish naturalist) explored the West Coast on board The Discovery with Captain George Vancouver in the 1790s.

In the fall of 1793, the ship anchored in Bodega Bay and Menzies and other crew members landed on shore.  Here's a passage from his journal:

"We landed on the west side & ascended the high ground which formd the bluff/headland/in expectation of a fine prospect which was however very limited from a thick fog that enveloppd the inland country...the grass & brush wood on this headland had been lately burnd down so that I had little opportunity here to augment my botanical collection, the few plants I saw were not different from those I had before met with at San Francisco & Monterrey excepting a new species of Sisyrinchium with yellow flowers of which I brought on board live plants for the garden."

From: Menzies and Eastwood.  1924.  Archibald Menzies' Journal of the Vancouver Expedition.  California Historical Society Quarterly 2 (4): 265-340.


As I was reading Menzies' journal, I was envisioning the different places he visited.  The above description surprised me because if you followed in Menzies' footsteps today (over 200 years later), you would encounter Sisyrinchium californicum in the same place that he did!  It grows along Westshore Road in wet places along the base of the bluffs on the inside (harbor side) of Bodega Head.

[Note: If you read the full article mentioned above, you'll see that the author (Alice Eastwood) suggests that Menzies was exploring Tomales Bay/Point Reyes in the passage above, rather than Bodega Head.  But after reading the journal carefully and matching Menzies' descriptions to the landscape and local conditions, I think she may have been mistaken I think he was on Bodega Head.)

Wednesday, May 23, 2012

Wind and sand

The wind has been blowing at 20-30 knots out of the northwest since yesterday afternoon.  Not atypical for Bodega Bay in the spring!

The strong winds created some intriguing sand patterns at Doran Beach this morning (23 May 2012).

Harrow marks on the upper beach 


Although I'm not a geomorphologist, I've read that harrow marks often form with a combination of wet sand and strong winds.  With differential drying, the wet sand resists the wind and the drier sand accumulates in the lee.  To my eye, the resulting raised structures look similar to comets with streaming tails.

Here's a close-up.  Can you tell which way the wind was blowing?

Above, the wind was blowing from left to right. 


Some alternative names for these structures include sand shadows, sand tails, wind drifts, and wind shadows.

Here's another photo, taken from the opposite direction.


Sometimes harrow marks start with a small object like a shell fragment, a stone, or a piece of wood.  The object causes turbulence, and the wind velocity is reduced on the downwind side causing sand deposition.

When I zoomed in to one picture, I realized that you could see the sand streaming by.  Look for the fine lines set off by the darker backgrounds on the sides of the harrow marks. 


Several lines look like they're arching upward, a clue that some of the sand grains are being transported across the surface by saltation (leaping).

Tuesday, May 22, 2012

The hydrocoral and the worm

Purple hydrocoral (Stylantheca porphyra)

This beautiful encrusting sheet is a colonial animal growing in the low intertidal zone on wave-exposed rocky shores.  It looks like a coral, but is more closely related to hydroids, hence the name "hydrocoral."

Here's a close-up of a smaller sheet (~4-5 cm across).


Stylantheca porphyra is found from British Columbia to central California, but is encountered infrequently on Bodega Head.  This striking hydrocoral grows on vertical walls and is often associated with other colorful low zone groups (tunicates, sponges, hydroids, anemones, etc.) — resulting in a brilliant mosaic (see below).

 
Each star-shaped pit within the calcareous skeleton contains from 1 to 12 feeding polyps.  Below is a view through a microscope.


Interestingly, Stylantheca is a brooder.  Medusae are retained below the surface of the colony where they produce gametes.  Female colonies brood larvae (called planulae) until they are fully developed and can swim or crawl away and settle on a rock.

When researching Stylantheca, I came across an article that mentioned a commensal worm (Polydora alloporis) that lives within hydrocoral skeletons.  The paper contained this picture, showing the worm's tentacles and the paired circular holes used by the worm.

From Light, W.J.  1970.  Polydora alloporis, new species, a commensal spionid (Annelida, Polychaeta) from a hydrocoral off Central California. Proceedings of the California Academy of Sciences 37: 459-472.


After reading this article, I reviewed previous pictures of Stylantheca and discovered that many of them appear to have these paired worm holes scattered throughout the colony!  See if you can find some in the photo below.


I don't know if this is the same species of worm, but it's likely to be related to Polydora alloporis.

Monday, May 21, 2012

The orange-legged conductor

If you've been following this blog, you can probably tell that I'm enamored with jumping spiders.  On 20 May 2012, I encountered one (or two) fascinating species in a disturbed, gravelly area with sparse vegetation on Bodega Head.

The first individual I saw had bright orange hairs covering the front legs, reminding me of an orangutan (or a yeti crab).  It also had a row of spiky gray hairs above its eyes.  See below for several views.


Then I noticed a few of these very small (only a few millimeters long) juvenile jumping spiders (next photo).  I wondered if these gray juveniles would grow up to look like the orange-legged adult?


But after looking further, I found a few adults predominantly gray in color.  See below for several views.


I was photographing a gray adult and was surprised when nearby movement caught my eye and an orange-legged adult appeared and started to display.  It moved its palps up and down very rapidly, and then extended its bright orange legs vertically, like a music conductor!


Beautiful color patterns and intriguing behaviors!  Now I'm wondering if these are the same species?  Is it possible the males have orange legs and the females are gray?  Could this be Habronattus tarsalis?  If anyone can help with the i.d., I'd love to hear more.  

Sunday, May 20, 2012

Crescent of fire

View of a partial solar eclipse from Bodega Head on 20 May 2012.


Photos were taken between 6:01 p.m. and 6:54 p.m.  They are in chronological order, starting in the upper left corner and ending in the lower right.  The center images were taken at 6:29 and 6:31 p.m., the peak of the eclipse in our area.  During the eclipse, ambient light levels became noticeably dimmed.

At sites further north in California, an annular eclipse produced a complete "ring of fire", but at our latitude/longitude the eclipse was more like a "crescent of fire."

The silhouette of the moon moved across the sun from the southeast quadrant towards the northwest quadrant.  You can see it coming in from the lower right and leaving from the upper left.

Quite a sight!

Saturday, May 19, 2012

Back in black

A high-pitched whistling call led me to this seabird floating just offshore of Bodega Head today:

Pigeon Guillemot (Cepphus columba)


Pigeon Guillemots are primarily seen in the Bodega Head area from late spring through fall.  They forage near shore at depths of 10 to 30 meters, and a few pairs nest in cavities on the outer cliffs.

They're known for their black plumage with white oval wing patch.  Also distinctive is the bright red lining to the mouth and the red legs and feet (see below).

Photo taken on the South Jetty in 2007.


  The large webbed feet are used for both propulsion and steering while diving.   
Photo taken on the outer coast in 2009.


On the West Coast, Pigeon Guillemots range from Alaska to California.  One of the largest breeding concentrations occurs at the Farallon Islands, with over 2,000 pairs (Ewins, 1993).  

In an unusual migration pattern, birds nesting in California fly north for the winter, as far as British Columbia.

Welcome back, guillemots!

Friday, May 18, 2012

Pink and lavender

The only two plants in the Plumbaginaceae (Leadwort) Family on Bodega Head.

The first is found along coastal bluffs and is flowering now.  The second grows in the salt marsh and blooms during the summer.  Look for their similar 5-petaled flowers.

Sea Thrift or Sea Pink (Armeria maritima)



 Sea Lavender or Marsh Rosemary (Limonium californicum)