Western Australia 337 (Stoinis 61) and 9 for 383 dec (S Marsh 85, Stoinis 57, M Marsh 53, Agar 76*, Bird 5-78) drew with Tasmania 397 (Paine 121, Jewell 52)
Bird, who finished with 5 for 78, removed Josh Inglis, Cameron Green and Jhye Richardson in the space of six deliveries - all to catches by Tim Paine, the second a terrific leg-side take - at which point Western Australia were 238 runs ahead with 46 overs still remaining in the day.
However, Agar and Joel Paris, who batted with a runner after suffering a hamstring injury earlier in the match, added an unbroken 85 for the tenth wicket and any chance of a positive result had been nullified well before Western Australia declared to end the game.
They had resumed with a lead of 88 but both Marsh brothers departed inside the first hour to give Tasmania hope of pushing for victory. Mitchell Marsh bunted a return catch to Bird in the opening over before Shaun Marsh edged an excellent delivery from Sam Rainbird 15 runs short of a century.
Debutant Lawrence Neil-Smith continued his impressive match by removing Josh Philippe, caught on the rebound by Bird at first slip, but Marcus Stoinis held Tasmania at bay with his second half-century of the match which was brought up with a mighty pull for six.
After Stoinis edged a big drive to slip Inglis and Agar added 51 for the seventh wicket to stretch the lead over 200 but Bird's intervention meant the home side were grateful for Agar sticking it out along with No. 11 Paris.