Roger,
I'm not sure what the regs say about climbing around birds, or near nest. We only climb these trees when Dept. of Fish and Wildlife has small jobs. We do try to pick times when we know the birds might be gone. However, they don't leave for very long, only 2 to 3 weeks at a time. This pair will begin to build the nest up soon, from what I'm told, activity will increase.
The Pics are from my camera