At first glance, it seemed like good news. The four main television networks announced their viewership was down 2.5 million this spring over the same time last year.

At long last, I thought, people are fed up with the mindless trash, the "reality" shows that have as much to do with reality as Disneyland's Matterhorn has to do with mountains in Switzerland. They're tired of shows that, a recent survey showed, spew an average of 8.2 swear words per hour during what used to be known as family hour. They have rediscovered the joy of reading, or maybe they're in the park breathing fresh air and spreading picnic blankets.

Then I shook my head and came to my senses. I reached in my briefcase and found the pvp (short for portable video player) I wrote about a few weeks ago. "You," I said, not altogether in disgust. "It's your fault."

The pvp just stared at me, waiting with blind obedience for my next command.

Last summer, a conservation biologist at the University of Illinois-Chicago by the name of Oliver Pergams published a study that looked closely at why fewer and fewer Americans are visiting national parks. That decline started in 1988 and continues to this day. It reversed what had been 50 years of steady increases.

What he found has, I believe, a lot to do with understanding the decline in commercial television viewership.

Pergams looked at a variety of possible reasons people don't visit parks. His conclusion was to coin a new word, "videophilia." He defined this as "the new human tendency to focus on sedentary activities involving electronic media."

Consider some of the facts in his report: In the prehistoric year 1987, Americans on average spent zero hours on the Internet. By 2003, that had increased to an average of 174 hours per year, and it likely has risen a lot since then. In 1987, Americans spent an average of zero hours per year playing home or hand-held video games, compared with 90 hours per year in 2003. Movies were around in 1987, as were VCRs, but today we spend about 63 hours per year more watching them than we did in 1987.

Add it all up and we're spending 327 more hours per year, per person, on electronic entertainment today than we did then.

Pergams' study notes, with a touch of sarcasm, that we still have 24 hours in each day, seven days in each week and 52 weeks in each year, just as we did in 1987. If you're spending 327 more hours each year tethered to earphones, guiding a mouse over a game screen or otherwise being stimulated or entertained, you probably won't have much time left over to visit a national park.

I would add that you wouldn't even have time left over to mow your lawn, except that many of us manage to get that done with the aid of an mp3 player and headphones amped up to drown out the roar of the mower.