Who hung compact disks in my hedge?

It was a humid morning.  The sun was finally up high enough to begin shining through the tree canopy and into the hedge, and looky, looky!  A couple of dozen silvery compact disks seemingly hung randomly around.  A bit of closer inspection and they turned out to be highly regular orb spider webs, wet with dew, and reflecting the sunlight.  Ordinarily webs are pretty hard to see and in the tropics TPP has been clothes-lined by spider webs many times.  This may take some explanation.  Back in the old days of less energy consumption, "the wash", i.e., washed clothes were hung outside on clothes lines to dry.  And the lines were not very high, and so maybe you forgot as you ran through your yard, or the neighbors yard, never mind why you were running there at night, there was a good reason, and then one of these clothes lines would catch you right across the neck, and you would be on your back looking up at the sky, thus the expression. It was worse if you were riding a bicycle.  And later you find out the line was deliberating strung across a yard to take care of those "derned kids", any kids other than your own angels, who rode across their yards at night.

It takes a lot of energy to build such a nice insect trap as a web, so from the spiders point of view, you don't want some bird to come ripping through the hedge and  destroy your web.  This also may explain why so many webs were sort of clustered together, so they are more conspicuous. In the tropics the big orb building spiders were called bird-eating spiders because feathers would be found in webs where some small bird having flown into a substantial web would lose a feather although probably not their life (they were big spiders, at least the females, but not that big.).  There actually is a bird-eating spider, but of the tarantula type and not an orb-weaver.  Appropriately enough when cooked they are said to "taste like chicken".  
Our local orb webs all seemed pretty intact and highly regular indicating little if any prey of other damage so far.  At any rate these predators were left undisturbed to do their jobs.