ABC will make several expected scheduling moves in March, giving ABC News’ “Turning Point” the 10 p.m. Wednesday hour and Wind Dancer Production Group’s “Thunder Alley” the slot leading into the company’s established hit, “Home Improvement.”In addition, ABC announced that Steven Bochco Prods.’ family drama “The Byrds of Paradise” will air at 8 p.m. Thursdays starting March 3, with the Stephen J. Cannell Prods. hour “Missing Persons” completing its 18-episode run next week. “Thunder Alley,” which stars Ed Asner, will air at 8:30 Wednesdays beginning March 9, the same night “Turning Point” arrives. ABC, which owns a piece of “Alley” through its two-series pact with Wind Dancer, is expected to sandwich the new Matt Williams sitcom between “Home Improvement” episodes for up to four weeks as a means of establishing the show. ‘Birdland’ flies coop As part of the changes, two Columbia Pictures TV series, “The Critic” and the Brian Dennehy drama “Birdland,” will go on hiatus. The former continues until the end of the month, while “Birdland” has already finished its current run, with specials slated through the balance of the February sweeps. Neither show helped its long-term cause much Wednesday, as “The Critic” (a 10 .4 rating, 15 share) dropped slightly off “Thea” to its worst household rating in three tries,while “Birdland” (9.3/15) continued its gradual decline. ABC won the night in households and key demos thanks to the “Improvement”-”Grace Under Fire” combo, despite the highest rating since March for a controversial segment of CBS’ “48 Hours” (16.2/27). News at 10 Hollywood production companies have long fretted about losing the 10 p.m. hour Wednesday to ABC’s news division, which already controls Thursday and Friday with “PrimeTime Live” and “20/20.” Producers fear that another newsmagazine (ABC’s fourth, counting “Day One”) will limit opportunities for drama series. Suppliers were heartened, in fact, when a recent Wednesday airing of “Turning Point” drew mediocre numbers, simply cannibalizing some of the “48 Hours” audience. ABC and the other networks are scheduling various midseason shows to gauge their viability in advance of announcing their fall schedules in May.