Rod Davies, landlord of Gosforth Hall Inn, said: "The guy flipped for whatever reason. Whether it was pre-meditated, we don't know.
"We've heard he returned home and shot his mother. Then he has gone on a spree to Seascale, where he's believed to have caused two fatalities.
"He then left Seascale and went through Gosforth where he's believed to have killed a local farmer - shot him at point-blank range."
Boot Inn landlord Sean King said that fellow publican Harry Berger, who runs the Woolpack, was shot in the arm in Seascale and was recovering in hospital.
A member of staff at the Woolpack Inn said a girl had received minor buckshot wounds.
A Whitehaven cab driver said he understood a total of three taxi drivers had been shot, two fatally.
The man, who did not want to be named, claimed an argument broke out between Bird and the other three men at the Duke Street taxi rank.
Later Cumbria Police confirmed that Bird's mother was alive.
The force issued a statement saying: "We can confirm that Mrs Bird (mother of Derrick Bird) has not been shot, she is alive and is being supported by her family."