they die or lose their mate
Yes
yes they do
yes. they migrate short distances
Yes
yes they have a brown body with dark spots for camouflage while nesting
Blackbirds reproduce by laying eggs.
Yes, they migrate short distances.
a group of Blackbirds is called a murder
There is no specific collective noun for blackbirds but any collective noun for birds will do; for example a flight of blackbirds or a flock of blackbirds.
Blackbirds
Blackbirds symbolize misfortune