Whether it’s pre-holiday doldrums or fans are simply tiring of them, veteran reality series “America’s Got Talent,” “Big Brother” and “So You Think You Can Dance” looked particularly sluggish on Tuesday, with each setting or approaching lows.

NBC won the night behind “Talent,” which was easily Tuesday’s top draw despite its latest declines.

According to preliminary national estimates from Nielsen, “America’s Got Talent” averaged a season-low 2.3 rating/7 share in adults 18-49 and 9.3 million viewers overall from 9 to 11 p.m. — down 12% from its previous season low set last week (2.6). Earlier in the evening, NBC aired repeats of “Betty White’s Off Their Rockers” at 8 (0.8/3 in 18-49, 3.4 million viewers overall) and 8:30 (0.8/3 in 18-49, 3.6 million viewers overall).

At CBS, “Big Brother” (1.8/5 in 18-49, 5.6 million viewers overall) ran second to “America’s Got Talent” and was nearly on par with its Sunday averages as the show wrapped its first week. As it turns out, this will be the show’s only Tuesday episode, as CBS decided this week to revert “Big Brother” to its Wednesday-Thursday-Sunday format of recent years.

Book-ending “Big Brother” on Tuesday for CBS were encores of “NCIS” (1.1/4 in 18-49, 8.2 million viewers overall) and “Person of Interest” (0.7/2 in 18-49, 4.1 million viewers overall).

SEE ALSO: http://variety.com/2013/tv/ratings/cbs-big-brother-back-on-familiar-schedule-turf-1200504194/

Fox’s “So You Think You Can Dance” matched its low to date (1.5/5 in 18-49, 4.3 million viewers overall), ranking third from 8 to 10.

Another slumping reality show is ABC’s “Extreme Weight Loss” (1.0/3 in 18-49, 3.4 million viewers overall), down 17% (0.2) from last week and ranking fourth among the major nets from 8 to 10. It was followed by an encore “Body of Proof” (0.6/2 in 18-49, 3.0 million viewers overall).

Univision ranked third on the night in 18-49, led by “Amores Verdaderos” (1.6/5 in 18-49, 4.1 million viewers overall).

Preliminary 18-49 averages for the night: NBC, 1.8/6; Fox, 1.5/5; Univision, 1.4/5; CBS, 1.2/4; ABC, 0.9/3; Telemundo, 0.7/2; CW, 0.2/1.

In total viewers: NBC, 7.4 million; CBS, 6.0 million; Fox, 4.3 million; Univision, 3.7 million; ABC, 3.3 million; Telemundo, 1.7 million; CW, 0.6 million.