I've known Scottish travellers who used to make a good living from harvesting pearls from freshwater mussles. They used to live in a settled environment (house) in the winter then go travelling with their van during the summer months and sleep in a 'bender'. Their 'season' started whenever the yellow flowers came out on the gorse bushes - then they were off on the roads. At the end of the season they'd sell the pearls to a local agent and that would keep them through the next winter. They'd augment the pearl fishing with fruit picking as and when it was available.
I've seen one traveller drape a coat over a stick in the middle of a field where hare were present. The hare was watching the coat so intently the man just walked up behind it and picked it up.
Another traveller tip I picked up was catching pheasants with a coke bottle. The man used an old coke bottle and pushed it down into the earth and wiggled it around to make a fairly deep hole. He poured some grain into the hole and led a trail of grain away from the hole for about ten feet. Then he did a few more.
The pheasant came along and started eating the grain. It worked its way up to the hole and stuck its head in to get the grain at the bottom. In trying to get the grain out of the very bottom, the pheasant, being full by now, usually fell in and was stuck. Then the man came out of hiding and picked up the pheasant and stuck it in an inside pocker of his poacher's coat. The coat had half a dozen large pockets sewn into it. He kept the birds alive in the pockets in case the gamekeeper came along, and if that happened he'd just open the coat and the birds flew out - no evidence!
It's amazing what tips you can pick up. I used to meet loads of travellers when I was younger, back in the sixties. I'd hitch hike all over Scotland with just a sleeping bag and a sheet of polythene. Rough camping I called it, you know the drill. Cook on an open fire, make your own shelter, catch your own dinner and so on. Armed with the meagre gear I had, I was often made welcome by the travellers round their fire, although as far as I know there is no traveller history in my family. I might be a throwback though.
Eric