• by Wayne Friedman , September 2, 2015

Only four of 15 networks witnessed gains in overall Nielsen viewership in prime time, with TNT still leading all channels versus a year ago but down 22% to 1.95 million prime-time viewers.

Gainers included Fox News Channel, up 9% to 1.93 million; HGTV gaining 13% to 1.6 million; Discovery Channel adding 19% to 1.59 million; and AMC improving 11% to 1.03 million.

Big decliners were USA Network, in fourth place, down 18% to ESPN (13th place) sinking 33% to 1.03 million; and FX (10th place), off 13% to 1.1 million.

USA is still the leader among 18-49 viewers in prime time, but losing 17% versus the summer 2014 to now average 764,000 viewers, according to Nielsen.

Discovery also made big gains to land in second place, up 11% to 723,000 18-49 viewers. Turner’s networks TBS and TNT both lost ground, down -- 19% and 23%, respectively. TBS was in third place, and TNT in fourth.

Younger 18-34 viewers are also led for USA Network, which was down 20% to 360,000. Adult Swim was next, slipping 2% to 355,000. TBS was down 25% to 310,000; and Discovery Channel gained 10% to 279,000.

Viacom networks MTV, VH1, and Comedy Central saw major declines. MTV was down 30% to 263,000, VH1 gave up 20% to 241,000, and Comedy Central was down 28% to 193,000.

The current summer ratings are a blend of Nielsen live program-plus-seven days of time-shifting data from June 1 to August 30 of this year and live program-plus-same-day of time-shifting, August 17 to August 30.