She spends “like half the day” on her phone, 14-year-old Abigale Wolfe said with a laugh when asked about her cellphone use.

Abigale, a local student who was visiting the Mall with her parents recently, isn’t the only one. Today’s teens spend more than 71 / 2 hours a day consuming media — watching TV, listening to music, surfing the Web, social networking, and playing video games, according to a 2010 study of 8- to 18-year-olds conducted by the Kaiser Family Foundation. The study also found a particular rise in time spent on mobile devices and an overall increase of about an hour and 20 minutes since 1999.

Teens today, also known as the Facebook Generation or “digital natives,” are part of the first U.S. generation to be so closely identified with technology.

For most teens, the big increase in screen time is on their cellphones. More than three-quarters of all teens own cellphones, according to a 2011 study conducted by Pew Internet and American Life Project. This is an increase from the 45 percent of teens who owned cellphones in 2004, Pew said.

Teens use their cellphones to text (an average of 60 times a day, according to the Pew study), check Facebook, play games and listen to music.

Vanessa Van Petten is the author and creator of the Web site Radical Parenting, which offers parenting advice written by kids. She said this is a direct result of what she calls “hybrid life.” For previous generations of teens, she said, “There was technology time and there was offline time. Now, there’s no separation.”

“From the time I get home until I go to bed, I’m usually on my computer,” 14-year-old Ben Knight, who was recently visiting Washington from Pennsylvania, said when asked about how he spends his time. As he toured the National Air and Space Museum, he said one of his favorite things to do online was visit flight- and rail-simulator Web sites.

Despite the heavy integration of technology into most aspects of daily teenage life, teens are spending time unplugged.

Ben said he goes for bike rides with his friends in nice weather, and he is more likely to stay inside with his video games in bad weather. “In the summertime, we may play a couple of rounds [of video games], and then it gets boring and we head outside,” he said. “I don’t like staying inside all the time.”

There has been a big decline in how much time teens engage in unstructured play — “just going outside and playing ball,” said Sandra Hofferth, a professor at the University of Maryland’s Department of Family Science. “Children are still playing sports and engaged in extracurricular activities.”

According to the Bureau of Labor Statistics’ 2011 American Time Use Survey, high school students spent on average less than an hour per weekday on sports, exercise and recreation.

As digital media becomes more integrated into daily teenage life, child development and education experts have begun to identify the unique opportunities it offers, including easier access to information and new opportunities for learning, as well as the negative impacts on adolescents, particularly the development of their social skills.

“There’s much more interactivity and learning that can take place with new media,” Hofferth said. “You don’t interact with a television.”

Alivia Moe, a 14-year-old high school freshman from North Carolina, said she learned to play the ukulele by watching lessons on YouTube. “I don’t have much time, and it’s hard to make appointments [for music lessons],” she explained. She said she also uses her smartphone mainly to text, shop and check in with her 585 Facebook friends.

But some experts say they worry that teens spend so much interacting with each other on social networks and phones that they are growing less comfortable with in-person interactions and not developing essential social skills.

“It’s much easier to look at a phone than to look someone in the eye,” Van Petten said.

Still, she said, parents from previous generations fretted about the ill effects of rock-and-roll when it was first introduced.

“There are always things to be concerned about,” she said.