December 30, 2005: Micro-building and unbuilding: Happy New Year
About spider silk and its mechanical properties (stronger than kevlar)
Many of you know that my addiction to building and unbuilding started at
the micro level. About 4 years ago, a banana spider,
Nephila clivipes
appeared in our garden. Usually when I walk to work, my curious eyes are
still sleeping. Having never paid much attention to spiders before, I
just walked by her web (about 12' between supports and about 4' in diameter).
But as my curious eyes woke up, I noted that she was doing something
each morning - and late in the afternoon, she was just sunning herself. What
spiders have behavior? So I started watching her in the early morning and
saw that she was weaving half her web - and then tomorrow, weaving the other
half. Her
weaving
was like a dance.
I named her
Natasha because
her movements were as delicate as that of a ballet dancer and
each morning she was performing some sort of ballet - similar to what
I had seen at the Bol'shoi in Moscow and at the Mali in St. Petersburg.
Natasha's
silk is special and is the
strongest (in tensile strength) fiber known
including kevlar.
My mother-in-law and sister-in-law live in Plant City Florida in an
area called Walden Lake. There is a jogging path in the forest surrounding
the lake, a perfect place to expect spiders to build their webs. So,
early in the morning, I go looking for spiders and their webs - though
I did not expect to find anything. Fortunately, my curious eyes are
in their high state of curiosity and soon I found many small spiders
and their webs. Some were building their webs, some webs were empty
and some had caught the morning dew. Here are the results - a great
way to start the new year, exploring building and unbuilding at a
micro-scale.
The spiders that I found were all members of orb-weaving class of spiders.
They all weave circular webs. While weaving, they build the radial
elements first and then when all the spokes are built, they start
weaving the circumferential elements - there is an example below.
and with her just-in-time dinner - a small bee or wasp
January 1, 2006 update: A better view of a crab spider
(Gasterocantha cancriformis) weaving.
Here is another potential dinner candidate
Here is a morning web that caught dew as well as insects
My first encounter with such a tangle of webs
Here are two webs - one is obvious and if you have your curious eyes
turned on, you can find the other web
Here, she is weaving her web and is building the 7th circumferential element.
Oops - I disturbed the web and she ran to the center - perhaps expecting
an early tasty treat. Look at the 8th circle (counting from the outside)
and you can see the remainder of what she was weaving as she ran for
the center.
Here is a
Leucauge venusta
just chillin' a bit waiting for dinner -
and there was not much of a wait. Here she is, preparing a small
insect for breakfast
When finished, she left the insect attached to the perimeter of the web
and resumed some weaving
Here is a close view
A January 1, 2006 update of her web. For each day that I have
walked along the path, her web has always been in the same spot. So
it is possible to update observations and improve characterization of her
behavior
This web was attached to a traffic sign - and the water droplets
refracted the light, making some color
Here is a single droplet
Flowers also caught some of the early morning dew - small droplets
on the small petals
This is definitely not micro but macro. I thought the reflection was
too good to pass up
Reflection 3
