Young man, turn on your television. Please. The networks are begging you.

Due to an exodus of 18- to 34-year-old male viewers, the networks' new TV shows are getting booted off the air faster than "Survivor" contestants this season.

Hyped programs like NBC's "Coupling" and Fox's "Skin" have already been dumped, and others like "Miss Match" starring Alicia Silverstone (NBC), "Karen Sisco" (ABC) and Rob Lowe's "Lyon's Den" (Fox) are seriously floundering. Even long-running favorites like "Friends" and "ER" have lost viewers.

As of this week, Nielsen Media Research (search) reported that networks saw 16 to 21 percent prime-time declines among men 18 to 34. Fox, up 11 percent in that bracket, was the exception because of baseball's postseason popularity.

Five of the six networks — ABC, CBS, NBC, UPN and the WB — also saw 3 to 14 percent prime-time declines among women that age, while Fox had a 12 percent spike.

So why are young viewers snubbing prime-time network TV? Experts say there are many reasons, including the quality of the shows and the increasing popularity of distractions like video games, DVDs and cable.

"One obvious answer is the hardest one to solve — it's the programming, stupid," said Robert Thompson, director of Syracuse University's Center for the Study of Popular Television. "Network television is searching for the next big thing. It's foul ball, foul ball, foul ball. They're still up to bat, but there's not a lot going on."

Some of the missing men echoed that sentiment.

"There's no reason to watch," said Michael Kingsley, 30, of New York, who makes exceptions for "24," "NYPD Blue" and "The Simpsons." "There's nothing really engaging out there."

That stance is particularly troubling during the November "sweeps" — a monthlong television ratings fest during which networks try to boost ratings and ad sales with enticing programming.

When news of the viewership dips first spread last month, shock waves ricocheted through the industry, which began scrambling to solve the case of the missing men (and, to a lesser degree, women).

"There has been a significant impact on all the networks, Fox in particular, because so much of our audience is young males," said Fox Broadcasting spokesman Scott Grogin.

Broadcasters immediately pointed fingers at Nielsen, which they've long been wary of and which this year adopted new research and sampling methods.

In response, Nielsen double-checked its data, with the same results, according to spokesman Jack Loftus. "They said, 'Nielsen, are you counting it right?' We did an analysis and we are counting it right," he said.

The networks said they're doing their own research just in case.

But even some network execs have acknowledged the fall lineup isn't stellar.

"Some of the programming just sucked," NBC Entertainment President Jeff Zucker admitted at a recent panel discussion.

In any case, the slump spells financial panic for the advertising-supported networks, which lust after the 18-to-34 demographic because it's an age group on the prowl for new products.

"When a broadcast network guarantees advertisers a certain audience and the overall levels decline, that is cause for concern," said Loftus.

Some experts have also pointed to a combination of the boom in DVD sales, growing Internet usage and an increase in video-game playing as factors contributing to the decline.

"That demographic is very good at finding entertainment from all sorts of sources," Thompson said.

Additionally, cable has drawn viewers away from the networks, with HBO's cutting-edge shows like "The Sopranos" among the favorites.

"It's not that they're watching less TV — it's that they're watching less network TV," said Thompson.

Ad-supported cable viewing was up 1 percent among men in that bracket and 9 percent among women as of Nov. 16, according to Nielsen.

But the 18-to-34 set is also notoriously fickle.

"These young viewers come in and out of television in fits and starts," Loftus said. "It's a volatile age group."

For some men, changes in tastes and lifestyle are behind the shift. David Kardon, 32, of San Pedro, Calif., is now married with a 2-year-old, and finds he doesn't like dramas and sitcoms as much as he used to.

"It's me getting older and having other priorities and not as much time for television," he said.

Television viewing has declined over the last decade, according to Nielsen, but the numbers went up again between 2001 and 2003 — until this fall season, which began in September. News of Sept. 11 and the Iraq war could account for some of the spike, said Loftus.

So could the fact that the current 18-to-34 TV audience is actually younger than it used to be.

"The dynamics of that market have changed and it's now skewing more towards 18 to 24s," Loftus said. "Older folks in that break tend to watch more [TV]; younger folks watch less."

Whatever the motivation behind this season's unexpected slip, one truth remains: Television is cyclical. Thompson pointed to how "The Cosby Show (search)" and other hit programs helped jump-start NBC's 20-year winning streak in the early 1980s.

"All it would take would be one season," he said. "Get a couple of good shows these people want to watch and it will turn around very quickly."

News Corp. is the parent company of Fox TV and Foxnews.com.