I was reading your discussion about nestboxes.
Our biologists put up nestboxes, when they know a falcon is nesting in a spot.. The reason for this , is to protect eggs and young from inclement weather .They use covered nestboxes and have started putting bars in the front to deter geese and I forget what else.
When they were bringing the falcons back from the brink, so to speak, they wanted to do everything possible to make their nesting successful.They found that when they were just on a ledge , they were loosing chicks. They would drown. ( not all the time) It depended on the weather that season.
Yes, in nature, itself, eagles, robins, etc. do not have this luxury , but if you can help , why not. I f the trays have drainage and rocks, they should do just fine, but these poor birds seem to have no protection.
but on the other hand look at Hamilton, they are on ledge. (although, I think their ledge is a little better. )
I asked one year about putting up nest boxes in other spots. We have many in our area, but I thought the outer areas. But I was told , the falcon will choose where to nest, and then you put up a box.
In one area they put up a box , after eggs were laid, and that did well that season , but the next year the female laid her eggs on the ledge. We will see where she nests this year.
You just have to look at Manitoba to see that sometimes the female nests in the box and for some reason, other years she uses the ledge.
I have learned an awful lot from our biologists as they were involved in the project of falocn recovery from the beginning, and they were learning as they went along.
so it is not as simple as it seems. But I do agree, that if you use a nest box , why not a covered one in areas where they get no protection from elements.( that does not mean they will use it). Ours have to follow a certain specification.
Thanks for putting up with my long winded message.
Remember they are cliff dwellers.