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Spider Fields
Mon Apr 28, 2003
Listen in RealAudio 
A flock of geese, a murder of crows, but what do you call millions of spiders congregated in a
field? Unbelievable, according to one McBride, British Columbia farmer last October.
Lying across Russell Jervis' 60-acre, fenced field was a cluster of tens of millions of spider
webs and silks. Responsible for this mess was a small black spider less than half an inch
long, called Halorates Ksenius.
Local biologists speculate that perhaps unusual weather conditions during the early fall --
rainy with light winds -- prevented the spiders from dispersing normally.
While such massive congregations are unusual, they are not exactly rare. Some spectacular
events occur in California's Yosemite National Park. Under ideal conditions, wind-traveling
spiders fill the air with enough silk to form a gossamer blanket 6,500 feet long and 4,000
feet high, arching over Sentinel Rock. At other times, millions of these small spiders drop
their own veil across Bridal Veil Falls.
Many spider species use the wind to disperse. Here's how it happens:
A spider moves to a location where winds are strong and swirling; it could be a branch, rock,
fence post, or a bush. It then positions itself with abdomen pointed to the air and ejects
fine silk threads from its spinneret. When the friction of the air upon the threads is great
enough to lift the spider from its perch, it lets go, and is carried to a new home by the
breeze.
Thanks to our contributing writer, meteorologist Keith Heidorn. The Weather Notebook is a
production of the Mount Washington Observatory, and is supported by Subaru and the National
Science Foundation. Special thanks to Executive Engineer Sean Doucette.
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