Friday, September 7, 2012

Pseudopupil

I learned something yesterday.

Yesterday something that looked, out of the corner of my eye, like a large clumsy moth/grasshopper careened by us and landed unceremoniously and loudly on a jasmine plant.   I went over to investigate and found a large mantis looking back at me.

I say looking back, because as I moved around it taking pictures, it appeared as though it's eyes were following me.  At least it looked like there was a pupil always aimed me, but I couldn't otherwise figure out how it's eyeball would move, and didn't they have compound eyes?

That is when I learned about the pseudopupil!

"In the compound eye of invertebrates such as insects and crustaceans, the pseudopupil appears as a dark spot which moves across the eye as the animal is rotated. This occurs because the ommatidia which one observes "head-on" (along their optical axes) absorb the incident light, while those to one side reflect it. The pseudopupil therefore reveals which ommatidia are aligned with the axis along which the observer is viewing."


I imagine this effect is just more obvious in the mantis, because of the size and color of their eyes.  And their willingness to hold still.  It did also turn it's head to follow my actions, giving the impression of more presence of mind than most insect encounters.

Another interesting factoid from Wikipedia "All S. Californicas have sensors near their legs that allow the praying mantis to lose its head and still function. This is good if the head is devoured during mating."  So much for presence of mind...

This one maybe the native Stagmomantis californica, California Mantis, but possibly the introduced Mantis religiosa - there seems to be a dark spot on the bicep, but I can't tell for sure.  I think it is a he, based on the length of the wings in comparison to the torso (thank you RandomTruth for the guidance on this and species!).  I hope he hangs around and catches some of the horse flies.

References:
http://en.m.wikipedia.org/wiki/Pseudopupil
http://en.wikipedia.org/wiki/Stagmomantis_californica
http://daviswiki.org/mantids

Saturday, August 18, 2012

Mama's boy

The little deer in the last post is growing up,  I think he even has the start of antler buds showing up. 



Although he's still a nursing baby.

Wednesday, May 30, 2012

Spring Babies

It seems like there are little babies starting to come out and about all over these days.

There was the little deer that came by the kitchen about 2 weeks ago.

Then the turkey brought her flock of poults by for some foraging.  




Then the lone duckling catching the first morning sun with it's mother.


Then the young turtle basking on a log (about the size of two silver dollars).



The froglets, many still with their tadpole tail
For size reference, these are a child's hands
Then just today, the Chickadee fledgling getting fed by it's attentive parents in the front yard.



Sunday, May 6, 2012

Hawk Spa

One of the great things about camera traps, is the glimpse into the behavior of wildlife when they are quite sure no one is watching.

I know that birds take baths, many of us have just fantastic bird baths to encourage this!  However, it seems that passerines are a bit less shy than raptors about bathing in public.  I never had the honor of seeing a hawk take a bath before I checked the cams last week.



This bird took it's sweet time in the creek.  From the time it first triggered the camera, until it flew off, it was in the water about 20 minutes, just before 10am.  That water is really chilly, it is in a nice shady riparian area.  It seems like it was moving in nice and slowly, getting it's toes and tail feathers used the the water, before going in for the full plunge.

The rest of the videos from this set are from wood ducks, floating upstream and downstream in front of the camera, and repeating, and repeating.  At least they are very pretty birds!  Hopefully we'll see them with babies in a couple months.


Monday, April 30, 2012

Baby Garden Spiders

Last year must have been a banner year for garden spiders.  This past month, we've seen many little clusters of newly hatched babies.  The babies are tiny, pin head size.  The top photo below is next to a standard size household rain gutter, for size comparison.



The babies tend to stay in a tight ball, all on thin webs clustered together.  If the web is disturbed, by wind or physically touching part of it, the spiders scatter in a tiny little cascade, dispersing any target.  If the disturbance does not continue, they all pull back into the cluster in a few minutes.

I think these are cross-orb weavers (Araneus diadematus), a stow away from Europe.


Spidey-facts


Watch one of the adults building a web - http://www.bbc.co.uk/nature/life/European_garden_spider#p00grb0l



Tuesday, March 20, 2012

Red Shouldered Impressions

In the My Side of the Mountain post, I mentioned we have a nesting pair of Red-Shouldered Hawks nearby.

Usually I just hear them, and see them riding the thermals above the valley.  But recently, they have been hanging around much closer to the houses.  In February my son looked out the kitchen window and casually asked "What's that bird?".  I was in the other room and asked "What does it look like?"  His response was "A Turkey", but I was thinking he probably would have just said "Turkey!" to begin with if that is what it was.  I came in and looked, half expecting a Turkey, and was shocked to see a Red-Shouldered Hawk flapping it's wings to keep it's balance on the ground on the steep hillside.  It looked like it had landed trying to catch something on the ground.  We only got a chance to snap this one picture with my phone before it flew off.   Just think of it as my version of a homage to Monet.

Impressionism Red Shouldered Hawk






































Luckily, this bird or it's mate returned this morning.  It perched on the branches of a recently deceased tree, and worked on prying off small branches for about 10 minutes.  I imagine it is working on a nest nearby.


Red-Shouldered Hawk Pulling on branch

I was thrilled to get a chance to watch the bird work on this project, and get a few more photos.  My son got to see it also.

And in hindsight, it kind of does look like a Turkey.

Special for JDS, here is an actual Turkey photo taken a couple of weeks ago, as follow up to the comments from an earlier post.


  Happy spring all.


Thursday, February 16, 2012

Bobcat Whiskers

I've gotten a number of bobcat images at this location, but they are all facing away from the camera, and most are at night.  I was thrilled this time, when this lovely critter came down the trail February 9 at 8:30 in the morning, came in for a close up, and even paused for effect.



This set covered much of January and half of February.  The previous few months there were a lot of deer images.  However, this set of images just had one deer trigger, and the deer was moving slowly, as though it may have an injury.  This set is in a suburban area, with lots of irrigated vegetation.  We have had a very dry fall and winter so far, and finally had a few days of rain in the past couple of weeks.  I wonder if the deer I've been seeing were hanging around the houses for the irrigated vegetation, then moved back to the open space areas when the rain brought up the natural vegetation.

Saturday, February 4, 2012

Pileated Pair

The Pileated Woodpeckers are just so striking to see (pun intended), and you know there are big old trees nearby somewhere whenever you see them.  There is a pair that lives on the hill above our house.  We can hear them calling during the spring and summer, and occasionally they come down to feed on the bugs happily eating our sickly oak tree (SODS strikes again).   Although I have heard the pair calling back and forth, I've never seen them together, until yesterday.  A second one flew into the frame while I was filming the first excavating.  You can hear them briefly greet each other, before they move to the opposite side of the tree, and one flies away.  A pair defends its territory year-round, so I imagine these are the same ones I often hear, and a pair member will not abandon a territory even if its mate is lost.




The Pileated Woodpecker is the largest woodpecker in most of North America, nearly as large as a crow with a large, dull black body and red crest. If you see one, you will immediately know it is something different than other local woodpeckers.  Its loud ringing calls and huge, rectangular excavations in snags indicate it’s presence in forests across the continent.  Only large-diameter trees have enough girth to contain nest and roost cavities of the large Pileated Woodpecker, so there is concern for populations of this woodpecker where old-growth forests are being converted to younger stands. Availability of suitable habitat is apparently the factor limiting most populations. In young forests, it will use any large trees remaining from before the forest was cut. Because these trees are larger than the rest of the forest, they present a lightning hazard to the nesting birds. 


The Pileated Woodpecker gleans insects (primarily carpenter ants and wood-boring beetle larvae) from branches, trunks, and logs, although it will also eat  fruits, and nuts. Because of its size and strong chisel-shaped bill, this woodpecker is particularly adept at excavating, and it uses this ability to construct nest and roost cavities and to find food. The pilieated woodpecker makes deep rectangular excavations in trees and logs in pursuit of insects.  These excavations can be so broad and deep that they can cause small trees to break in half. It will also pry off long slivers of wood to expose ants. 

Most woodpeckers also drum on objects as a form of communication and territory defense. When doing so, they try to make as loud a noise as possible, and that’s why woodpeckers sometimes drum on metal objects. One Northern Flicker in Wyoming could be heard drumming on an abandoned tractor from a half-mile away!





In its excavating, this species plays a crucial role in many forest ecosystems in North America; a diverse array of other birds—as well as mammals, reptiles, amphibians, and invertebrates—use its cavities for shelter and nesting.  The feeding excavations of a Pileated Woodpecker are so extensive that they often attract other birds. Other woodpeckers, such as the Hairy Woodpecker, as well as House Wrens, may come and feed there.

Woodpecker species have some really amazing evolutionary adaptations for their way of life.  Their skull structure, beak, tongue, tail, and even toes have special adaptations for drilling into wood.  Although each species of woodpecker is unique, and all vary in their particular adaptations, there are some general trends among the group that are impressive.

-      Skull/Brain:  If any of us tried to bang our head against a tree even once, much less at the force and frequency of the woodpecker, we’d have quite a headache (not to mention significant brain damage).  However, the woodpecker’s skull is specially designed to withstand repeated blows and to protect the bird’s brain from concussion. Woodpeckers are capable of repeated pecking on a tree at remarkably high decelerations (stopping time, also a measure of force) on the order of 10 000 m s2 or 1000 g.  There are three keys to woodpeckers' ability to withstand high decelerations: their small size, which reduces the stress on the brain for a given acceleration; the short duration of the impact, which increases the tolerable acceleration; and the orientation of the brain within the skull, which increases the area of contact between the brain and the skull.  Also, unlike other birds, the bones between the beak and the skull are joined by a flexible cartilage, which cushions the shock of each blow. 

-      Toes and Tail: To generate that much force, the woodpecker has to actually be firmly attached to the surface it is drilling into.  If it wasn’t, it would just knock itself off the tree after the first blow.  Woodpeckers have a special toe arrangement that helps give them the solid base they need.  This is arrangement is called “zygodactyl feet”, and consists of four toes, the first and the fourth facing frontward and the second and third facing back, attached to sharp claws and short-strong legs.  This arrangement is good for grasping, as well as walking vertically up a tree trunk.  The tails of all woodpeckers are stiffened, and when the bird perches on vertical surfaces, the tail and feet work together to support it.  Its sharp claws dig into the wood, and its stiff, square tail feathers braced against the tree act as a support prop.

-      Beak: Woodpeckers are noted for their stout, chisel-like beaks which they use to drill holes in trees to obtain food, make a nest/roost cavity, or territorial drumming.  Species of woodpecker and flicker that use their bills in soil or for probing as opposed to regular hammering tend to have longer and more decurved bills.

-      Tongue: After drilling a small hole with its beak, many woodpeckers, then use their narrow, probing tongue to dislodge and extract insects from their burrows in the wood or bark. The long sticky tongues, which possess bristles, aid these birds in grabbing and extracting insects deep within a hole of a tree. Some woodpeckers can even extend its tongue four to five inches beyond the tip of the beak to access hidden goodies such as insects deep in the bark. 

-      Eyes and Nose: The millisecond before contact with wood a thickened third eyelid (“nictitans membrane”) closes, protecting the eye from flying debris. The nostrils are also often protected by only having a slit-like opening, with special feathers to cover them.

I admittedly have a soft spot for these gigantic woodpeckers.  And luckily, that soft spot is in the cambium of our old oak.  


References:

Cornell Lab of Ornithology - http://www.allaboutbirds.org/
Cornell Lab of Ornithology - The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:http://bna.birds.cornell.edu/bna/species/
Gibson L. (2006) "Woodpecker pecking: how woodpeckers avoid brain injury" Journal of Zoology 270: 462–465 doi:10.1111/j.1469-7998.2006.00166.x
Short, Lester L. (1979). "Burdens of the Picid Hole-Excavating Habit". Wilson Bulletin 91 (1): 16–28. http://elibrary.unm.edu/sora/Wilson/v091n01/p0016-p0028.pdf.
http://www.friendsofcortemaderacreek.org/cn/WoodpeckersoftheWatershed.pdf 

Saturday, January 14, 2012

More cute kitten videos (the bobcat kind)

This last month, the bobcat and her kitten returned up the trail together, this time during the day.  I love how rambunctious this kitten seems.


Although Bobcats can be born throughout the year in this area, most are born in the late spring to early summer.  The young begin accompanying their mother on hunting excursions at about 3 months, and remain with her until the next litter is born.  I imagine this young one has just a couple more months with Mom.

The adult came up the trail first, and from the looks of the "Bobcat Boogie" footshake, possibly stepped in something wet and/or unpleasant on the way.


References:
The American Society of Mammologists Species Account.  http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-563-01-0001.pdf
Nature Blog Network