Despite claims from Facebook CEO Mark Zuckerberg that teens aren’t losing interest in the social network, a new study suggests that Twitter has become the most important network for teens as Facebook declines in popularity.

The study comes from Piper Jaffray, who surveyed over 8,000 teens and found that Twitter is now, for the first time, the demographic’s go-to source for their social media fix.

Twitter was preferred by 26% of teens, while Facebook held sway over 23%. This is the first time in Piper Jaffray’s reporting that Twitter has edged out the big blue giant.

Just 6 months ago, Facebook still held the popularity prize over Twitter – 33% to 30%. A year ago, 42% of teens surveyed said that Facebook was the most important social network in their lives.

This isn’t the first time that we’ve heard that Facebook is losing popularity among teens. During Facebook’s Q2 earnings call earlier this year, Mark Zuckerberg rebuffed such reports, saying:

“One specific demographic I want to address is U.S. teens. There has been a lot of speculation and reporting that fewer teens are using Facebook. But based on our data, that just isn’t true. It’s difficult to measure this perfectly, since some young people lie about their age. But based on the best data we have, we believe that we are close to fully penetrated in the U.S. teen demographic for a while, and the number of teens using Facebook on both a daily and monthly basis has been steady over the past year-and-a-half.”

He added:

“Teens also remain really highly engaged using Facebook. Now it’s also worth mentioning that these stats are for Facebook only. Instagram is growing quickly, as well, so if you combine the two services together, we believe our engagement and share of time spent are likely growing quickly throughout the world.”

Although saturation is an issue – Facebook already has over 1.2 billion monthly active users – the issue here isn’t total users. Piper Jaffray’s study looked at popularity, not total teen users.

Seemingly, in an effort to boost its standing among teens, Facebook recently changed its privacy settings to allow them to post publicly for the first time.

Image via Maryland GovPics, Flickr Creative Commons