When Blackbirds Are Nesting Can I Still Go Out In The Garden?

Yes you can nut head

Yes you may, if you do not fear for your head! Don't worry, only 10% of corvids and birds of prey actually attack people, and even then, it is only a minor inconvenience.

I understood you were more concerned about disturbing the birds than being attacked. I have a pair nesting in my greenhouse. So far I've only seen the male sitting the eggs, and sometimes he flies out with much screeching when I enter the greenhouse.  Can it be that my disturbances may cause him to forsake the nest?

I like to put up window spikes around the house in various places and if that dont work i result back to good ole manual labor with my .22 rifle it seems to be very effective against blackbirds and rabbits and not to mention rabbits are rather tasty if the cured and smoked on the grill !! Tasty!!! So good !