A couple of weeks ago, tired after a day of raking leaves, T and I collapsed in some chairs in the back yard. The warm sun felt good, and I laid back and stared up into the big bell of a clear blue autumn sky.
Small insects were backlit by the sun, glowing brightly. Milkweed and ragweed seeds drifting on the breeze caught the light, too. Then I noticed a long bright silver streamer, and another, and another. Looking more closely, and shading my eyes with a hand, I saw the air was thick with them, blowing by on the wind high above the trees:
Little yearling spiders were taking flight on this clear windy day. Crawling to some high point, as high as they could get, they were spinning out long threads of gossamer silk like spinnakers, and setting sail for parts unknown.
There were thousands. It was amazing how high they were, too. You may not be able to see it in the video – Youtube degrades detail horribly, and photography is really bad at conveying distance – but if you watch it in HD you might be able to see that they completely fill the air column, some easily a thousand feet up.
It’s a behavior known as ballooning or kiting. Some of the hapless argonauts catch on tree branches or power lines after only a short flight, or drop to the ground not far from where they started. But others travel amazing distances. Human sailors have found these arachnid sailors catching in their rigging a thousand miles from land. They’ve been sucked into the analyzing equipment of weather balloons 16,000 feet in the air. They can even get caught in the jet stream and, surviving up to 25 days without food, travel profound distances, colonizing mountaintops and islands far out at sea, even distant continents.
Pretty amazing little buggers.