Sunday, October 21, 2012

colonial orb weaver ~ 10/21/12 ~ Elkhorn Slough

Whenever I consider shutting down Nature ID due to the tremendous time commitment it requires, I'm reminded of the value of the personal narrative that's recorded as I learn about my local natural world.  Last summer while driving home from the grocery store I happened to meet a fellow who is the country's lead researcher on these unusual social spiders, which also happened to answer a question I had from the year before.  To read that post, click here.

Now, this past winter was definitely not an El NiƱo year, so it was interesting to find hundreds of these colonial orb weavers on Hummingbird Island and nowhere else we visited at Elkhorn Slough, exactly where the CA oak moths were most abundant - a great example of prey availability. Apparently, Metepeira spinipes are not always colonial.

In the first picture, above the spider are her egg sacs.  In the second picture, there are at least 3 different females, one in the center and the other 2 towards the top at 12:01 and 12:05 positions.  The plant they've spun their chaotic orb webs on is CA sagebrush (Artemisia californica).  And, here's a repeat link, because I like it so much in how these colonial orb weavers remind me of "Spiders on Drugs".

CA oak moth ~ 10/21/12 ~ Elkhorn Slough

For all the evidence I've seen of oak moths recently, like the total defoliation of oak trees at Garzas Creek and the crunchy munching at Toro Park, this is the first I've found the classic prolific pupae and moths on the wing this autumn.  Getting pics of the cloud of moths is difficult since they look like fuzzy tan blobs.  Even these photographs do a poor job at illustrating how the pupae were on any and every available surface.  We had oak moths like this at home this past spring, but for some reason a 3rd generation never materialized.  Country Mouse of Town Mouse and Country Mouse has a nice post of oak moths up near Santa Cruz.  This local abundance of oak moths leads into my next post...

arum ~ 10/21/12 ~ Elkhorn Slough

I've wondered what these are for quite a while, ever since I first saw them in a corner of the Memory Garden behind the Pacific House in Monterey.  Lately I've seen them more and more in yards here in town.  I attribute their recent proliferation to Trader Joe's offering cheap, decorative potted plants. Unfortunately, while you shop for pseudo-organic, cleverly packaged food products, many of their potted plants only include generic care instructions for water and sunlight without any identifying label.  This is the first time I've seen these growing in the "wild" outside of a tended garden.  Given Elkhorn Slough's history as a farm and the proximity of this bunch under an oak tree next to one of the barns, I suspect this is a waif from the past.

Without seeing the leaves or flowers, I can't easily tell which of the 25 spp. of Arum this is.  Calflora and Jepson eFlora list only Italian lords and ladies (A. italicum) and black calla (A. palaestinum, A. palestinum seems to be a misspelling) as occurring in CA.  The ones in the Memory Garden have a striking deep purple spathe, like the black calla, aka Solomon's lily, but several Arum spp. are also black.  If I had ignored the bright orange color of the fruit, I may have been able to figure out this was related to the locally prolific calla lilies (which surprisingly I don't have as a featured ID yet).  Oddly enough Arum and calla lilies are in the same Araceae family as duckweed.  Weird.

ps 08/19/13 - For a fun post on the related cuckoo pint (A. maculatum), check out Cabinet of Curiosities.

broad-footed mole ~ 10/21/12 ~ Elkhorn Slough

Hey, it's a mole!  Cool!  A dead one.  Aw, too bad.  Considering I've probably only ever seen one other mole in my life (it was dead, too, in the middle of a trail), I started wondering how I knew this was a mole.  I suspect many people would be able to recognize a picture of a mole without ever having seen one in person.  Why is that?  Children's books?  Nature shows?  Sure, I'd be able to recognize a panda or an alligator if I ever saw one firsthand.  But, moles?  They're not exactly wildly popular animals.

Then, the question for Nature ID becomes, "What kind of mole is it?"  This was a little challenging to research.  Most online pictures of moles are dead, and interestingly they all look like they've been licked by a canine or something.  I don't know why they have a wet licked look about them.  And why do they seem to go above ground to die?  I was fortunate to have found the kind with unusually large front feet to distinguish it from the numerous shrews.  There are 7 spp. of moles in North America.  Of those 7, 4 are found in CA.  Townsend's mole (Scapanus townsendii) and coast mole (Scapanus orarius) are found along the northern CA coast.  S. latimanus has the widest range in CA, but part of Monterey County is the southern-most area for shrew-moles (Neurotrichus gibbsii), which has a longer tail.  As a side note, in these scientific names here I've linked to, a database design site which for some reason contains the exact compilation of PDFs found on the California Wildlife Habitat Relationships website in association with the California Department of Fish and Game.  If you want to see larger range maps, select the common name on the CWHR site.  For an extensive sp. account published by the American Society of Mammalogists, check out Smith College>PDFs>No. 666 (it doesn't look like it links to anything, but it opens up a PDF to the publication).  While moles are reported to eat gastropods, beetles, and earthworms (see pub No. 666), it seems they have been targeted as an enemy of the gardener, like gophers.  Poor moles.