I've noticed that in almost al, the USA crow shooting videos I have seen, not ONE, not a single one, has used a whirly, and very few use floaters. I suppose its because your crows are a migratory species, and you are constrained by seasons too,mso people can't be bothered to invest in equipment other than the shells and gun. You also seem not to bother too much with camo.
Here in the UK (and most European countries) corvids are a species we shoot all year, and are classed as vermin. Due to being shot all year (and not being migratory), they are very well educated, very sharp of sight and hearing, and very difficult to get within range.
Hence we use lofted birds, floaters, rotaries, and peckers or flappers. Our hides are generally poles and nets, often covered with branches too, and we tend to dress in full camo gear with our faces covered in veils.
Most places electronic calls are totally forbidden for bird hunting (we can use them on foxes), and therefore we rely on the sight picture to bring them in close.
Here's a big three bird rotary in action (most are smaller arms and two bird) and they are generally made using a car windscreen wiper motor, running off a 12 volt battery
http://m.youtube.com/watch?v=yKZOY3JJq9A
How to make a rotary
http://m.youtube.com/watch?feature=related&v=Y-VqSXsY--Y#/watch?feature=related&v=Y-VqSXsY--Y
A floater
http://m.youtube.com/watch?v=yKZOY3JJq9A
And here's a pecker / flapper uses the same type of mechanism
http://m.youtube.com/watch?v=fHMSKTgh9mk&feature=related#/watch?v=fHMSKTgh9mk&feature=related
Can not speak for the other guys but here in the South we pay close attention to camo. We dress from head to toe with complete matching camo, face mask and gloves as well. As for setting up with all the wirlygigs and painted decs, we use a method called run and gun. In doing this method we are using mouth calls and game callers and are quit successful. There are times when we will ride and stop in proper cover 25 times a day and call and have killed as many as 220 in a single day doing so. We do use field setups when we can find a good peanut field that the birds are using but our numbers will typically only reach 100 to 150 doing so and after a while gets boring sitting and little action, so we turn back to run and gun.
We don't get the mass flights that you do in the states, and you can't just hop from one place to the next. Each place you shoot must be on your permission (I.e. written permission from the owner) and not having that is armed trespass with 5 years prison and £10,000.00 fine.plus loss of your weapons and licence, I.e. end of hunting forever lol
Permission is something that we always try to get before we hunt. Luckly most farmers here in the states hate the crow for its damage to the corn crop and others from the damage to the pecan crop and will invite us to hunt. We do have good numbers at times but we have to ride a bit to find them.
Nearly all our shooting is decoy or roost wood shooting, with generally being set up for the whole day. Mostly there are about two three major flights during the day, and the odd stragglers in between too, but sometimes there will be hours of nothing to do but wait. And sometimes, if there is enough food about one shot will mean them all just moving to another field. The birds here are used to being shot at (12 months a year here) so have become very wary and intelligent.
