Reader Jennifer sent several pictures of spiders and salamanders; here are two, with her one caption (click to enlarge).
Goldenrod crab spider [Misumena vatia] with bumblebee prey:
Wikipedia notes that this spider has chameonlike tendencies:
These spiders change color by secreting a liquid yellow pigment into the outer cell layer of the body. On a white base, this pigment is transported into lower layers, so that inner glands, filled with white guanine, become visible. If the spider dwells longer on a white plant, the yellow pigment is often excreted. It will then take the spider much longer to change to yellow, because it will have to produce the yellow pigment first. The color change is induced by visual feedback; spiders with painted eyes were found to have lost this ability.
The color change from white to yellow takes between 10 and 25 days, the reverse about six days. The yellow pigments have been identified as kynurenine and 3-hydroxykynurenine.
Wikipedia gives pictures of the color change. Because of its dimpled abdomen, I suspect that a crab spider is the subject of Robert Frost’s sonnet “Design” (below). It’s one of the Frost poems I like (“The Road Not Taken” has lost its force since I stopped believing in free will), and gives nice contrast between the horrors of natural selection and the natural beauty in which they’re embedded. The last line is ambiguous, but I prefer to believe it’s anti-religious—perhaps the despairing nihilism that we atheists are supposed to assume when convinced there’s no God.
I found a dimpled spider, fat and white,
On a white heal-all, holding up a moth
Like a white piece of rigid satin cloth —
Assorted characters of death and blight
Mixed ready to begin the morning right,
Like the ingredients of a witches’ broth —
A snow-drop spider, a flower like a froth,
And dead wings carried like a paper kite.
What had that flower to do with being white,
The wayside blue and innocent heal-all?
What brought the kindred spider to that height,
Then steered the white moth thither in the night?
What but design of darkness to appall?–
If design govern in a thing so small.
Jennifer also sent a red eft (Notophthalmus viridescens). The “red eft” is a juvenile stage of the red-spotted newt, common in the eastern U.S. It has three life stages: the larval stage, which has gills, and which then transforms itself into the reddish “eft” stage, which is a terrestrial dispersal stage that can last several years. (Natural selection can favor wandering abilities if the chances of finding a better pond give you higher reproductive ability than staying in your own—and presumably crowded—pond.) The eft then transforms into the final, adult stage, in which it finds a pond and becomes an olive-green, aquatic adult that is ready to reproduce.
Don’t forget to send your wildlife pictures to me (do make sure they’re good ones!) as well as cat pictures, with information enclosed about the animals and a paragraph or so about the cat.