Population X and Counting

In fiction, population signs tend to be updated in real time, whether to reflect new additions, or more often, to reflect a murder spree. A frequent means of establishing a "dangerous Wild West town" setting is a shot of the town sign, with several crossed-out population numbers, indicating frequent reductions due to violent deaths and/or people moving out. A ghost town may be shown with a sign that clocks all the way down to zero that way, presumably updated by the last resident to leave.

A specific sub-trope will have a killer be nice enough to peform a community service and adjust the population sign just before or after he offs someone.

Comic Books

 * Parodied in a story of the Italian Western parody Pedrito el Drito: a man has just finished painting a population sign when he hears a bang and updates the population. Then a baby is delivered, and the sign has to be adjusted again. Then there's a new shooting... Then the baby turn out to be two twins... Then four twins... Then the new father suicides because he can't support all of them... At last, the painter snaps and axes the sign into chips.

Film

 * The movie Oblivion establishes its Space Western credentials with a scene in which the bad guy moseys into town and adjusts the population sign to -1... with the blood of his latest victim.
 * The population sign was updated several times in My Name Is Bruce, as more and more people were killed.
 * This occurs in THX 1138. There was an "Officers in service" counter for robot policemen; after one was in a car crash, the number reduced by a tick.
 * Freddy's Dead: The Final Nightmare reveals that whenever Freddy kills he alters the Dream World version of the "Welcome to Springwood" sign to reflect the decreasing population.
 * Smalltown, USA in The Muppets has a population sign which flips, seemingly by magic, to keep the population count accurate whenever the main characters enter or leave the town.

Literature

 * In Bored of the Rings, the village of Whee has a welcoming sign announcing its population as "96 and still growing!" with 1004 and 328 each crossed out before it.

Live-Action TV

 * Sunnydale in Buffy the Vampire Slayer has a welcome sign with its population on it that appears on-screen several times during the show's run. In its earliest appearances, it lists a population just under 40,000; as the series progresses, though, that number steadily drops.

Theatre

 * Paint Your Wagon uses this to show the decline of Rumson's population from 4000 to 6.

Video Games

 * The town of Fyrestone has a sign like this on the outskirts in Borderlands.

Web Comics

 * There was also that incident in Looking for Group where Richard massacres an entire village, and on his way out, he crosses out the population counter on the sign, writing in a '0' instead. Using the blood of his victims as paint, obviously.

Western Animation

 * At the start of the Looney Tunes short "Drip-Along Daffy", a gunshot is heard, the population sign goes down one number and a sign reading "Sheriff Wanted" pops up. Pan over to the cemetery, where the population (listed as all sheriffs) goes up one number.
 * In the first episode of Doug, the Bluffington population counter ticks over by four as the family drives past it.