I've lost most of my previous winter greens to the wood pigeons, so decided to create a "cage" earlier this summer.
While the plants were young, they did much better than the uncovered ones on another part of the allotment. The latter were chewed to bits as usual, with only about half of them surviving (compared with 100% of those in the cage). However, the uncovered plants which survived seem to have caught up and are flourishing after the wet summer. I'll follow up to see how their crops compare.
This was my first attempt at carpentry since making an abstract sculpture in my first year at high school. I used some old bits of wood and at least half a pound of nails, then wrapped the whole thing in chicken wire. Also used one of the shelves from the mini greenhouse across the top. It took nearly a day to put it together, so I don't think I'll be taking up woodwork as a living anytime soon!