How to Harvest Swallow Guano (& turn it into natural fertilizer)

We had swallows roosting in the eaves, right above a table we used for outdoor dining. Birds nest above means poop below, and hence a very dirty table! We love having swallows around, so rather than try to move them on, we decided of course to turn a problem into a solution. We put a box of straw on the table, weighted down with a brick at the bottom so the wind didn't blow the box away, and let the swallows poop into their very own compost toilet! The box was easily moved when we wanted to use the table, the table stayed clean, and at the end of it we had a box of lovely guano and straw – a perfect addition to our compost heap!