A gift from Steve and Susan: a dancing and weaving Navphila
Susan just showed up in mid September at Steve and Susan's place She
was a standard banana spider (Nephila clavipes) in her behavior -
approximately half her web each morning, and feasting during the day and
night on anything that flew into her golden web. But because she is near
my home, she provides new opportunities to observe. Earlier this summer
I discovered the high frequency body vibration, apparently a defensive
response, in juvenile
banana spiders. So I
decided to test whether this high frequency reponse was preserved in
adults. The simple answer is yes and it can be induced by
plucking one of the support threads of the web. But the vibration
frequency is very slow - perhaps 2-4 Hz - since she has a rather massive
body to swing back and forth.
I really enjoy watching orb weavers weave and nothing is more beautiful,
elegant than the weaving ballet of the golden silk spider.
These photos are early morning and late afternoon.
The weaving starts close to sunrise when
the light is dim. I used a flash and bounce it off the wall behind the
web. Here are videos of weaving and photos of Susan weaving as well as
Susan just being Susan.
A surprise - I observed that Susan has
preserved something of her childhood dance - first observed with
Laura. As a child, Laura
vibration (I believe its a response to predators) was very fast, perhaps
40 - 50 Hz. Susan, being a mature adult, has put away some of her
childish behavior, has grown, is rather massive but still exhibits this
vibratory behavior. When I gently pluck once a supporting thread of her web,
she initiates about a 2 - 4 Hz somewhat irregular side-to-side rocking motion.
Below are videos of Susan starting and ending her dance.
Susan enjoying the sun (click any image for a large presentation)
Eating a tasty bee
In my launching position - waiting for dinner
Weaving: Note (click on the photo)
how she uses her legs to guide
the silk from the spinneret (see also
spinnerets with microscopy)
to the proper place for gluing to a radial fiber
More weaving - note that she uses the 4 legs nearest her head to
guide herself around the web while using the other 4 legs to guide the silk
and attach it to the appropriate web radial elements.
Who taught her to weave with such grace and beauty?
A wondeful and delicate ballet
Weaving with a careful look at that is going on
In my launching position - waiting, just patiently waiting (for something yummy)
This work is licensed under a Creative Commons License.
C. Frank Starmer