EPOW - Ecology Picture of the Week

Watch Your Face On This Trail!
Orb-Weaver Ahead!

Northern Golden Orb-Weaver (Nephila pilipes), Family Nephilidae
Mary River National Park, Northern Territory, Australia

Explanation:  With its web stretching eight to ten feet across the forest path, and nearly invisible in the dim, dappled light here at the floor of this monsoon rainforest in northern Australia, this northern golden orb-weaver has spun the perfect catchment.  But it nearly caught me -- in the face -- as I failed to notice it until the last instant.

This is a huge, and beautiful, example of the family of Nephilidae spiders known variously as golden orb-weavers, banana spiders, and -- quite appropriately -- giant wood spiders.
  

If you look closely, you can see what appear to be several
spiderlings in the denser part of the web
(and perhaps the tiny male, at right),
safe and sound between mom's enormous hind legs.

This specimen seems to have had a tangle with some predator, as she is sporting only seven of her usual eight legs.  

Some sources cite the distributional range of this species as including China, Japan, southeast Asia, India, and Papua New Guinea ("PNG") -- but not Australia, where I found this arachnid, in the tropical very "Top End" of Northern Territory, just across the strait from PNG.  (Minor lesson here about taking information from the "web" -- no pun intended -- at face value -- but other sources got it right.)

This species is nearly the world's largest spider.  We measured it at nearly 5 inches (13 cm) with legs curled on its web; outstretched, it would likely exceed half a foot!

This is one of five species of genus Nephila found in Australia.  Nephila specimens have been used for decades in research on the biochemistry of spider web silk.   

Here, this female northern golden orb-weaver is shown manipulating some insect prey she had captured and wrapped in her surprisingly-strong web fibers.  

The web silk is strong enough to entrap small birds! 

 

 

  

  

Information:
     Harvey, M.S., A.D. Austin, and M. Adams.  2007.  The systematics and biology of the spider genus Nephila (Araneae:Nephilidae) in the Australasian region.  Invertebrate Systematics 21:407-451.