Newt Gingrich had a productive spring season on the airwaves.

Who could forget his May 24 gabfest with Chris Matthews, in which the two explored everything from the history of the presidency to Mitt Romney to snakes? That was on MSNBC.

A week later, Gingrich went on “Morning Joe.” Topics included his previous talk with Matthews, to whom the former speaker referred as “slightly whacked.” That, too, was on MSNBC.

The same day, he also had a brisk dialogue with Anderson Cooper about Romney’s qualifications as a leader of the economy. That was on CNN.

More face-time: The former speaker pushed hard for Romney with David Gregory on “Meet the Press” on May 27. That was on NBC.

May 6 was a busy one even for the garrulous Gingrich. He did “Face the Nation” and “State of the Union.” Those were on CBS and CNN. Asked on CNN about his credentials as a campaigner, Gingrich noted, “I can get on TV fairly often.”

Gingrich walked through the open door to the “Situation Room with Wolf Blitzer” on May 3. That was on CNN. Just this month, too, Gingrich has made fresh appearances on both CNN and MSNBC.

Now let’s turn to his appearances on Fox News Channel. Google, whaddaya got? Hmmm, not seeing much recent activity. Nexis is perhaps a better measuring stick, good for checking prime-time and some weekend Fox stuff. Surely it has more information.

Not a chance: The most recent result to come up dates back months — unthinkable for a newsmaker of Newt Gingrich’s standing: Look at the interesting stuff that has happened over the course of the spring. First Gingrich strikes a defiant stance about staying in the race; then he eases himself from it; then he becomes an advocate for Romney. What Fox host couldn’t spin all that into a TV and Web hit?

Yet! April 9, according to Nexis, is the last time that Gingrich appeared as a guest on a marquee Fox program. That was an edition of “Hannity” in which the speaker and the host chatted about the deplorability of the media and the “future of our children and grandchildren.”

When asked whether Nexis could be missing something here, the Gingrich camp declined comment. Fox News didn’t respond to a request for comment, which is pretty much de rigueur for them vis-a-vis this blog.

Those non-responses leave little in the way of answers as to why Gingrich’s profile dropped on Fox at a time when his value to competing networks was strong. Were the Fox people tired of Gingrich after the heat of the primary season, when he nearly co-branded himself to the network? Were they not ready to have a serious discussion about animals?

Certainly Gingrich’s skimpy Fox exposure — and high CNN exposure — has nothing to do with his comment that “CNN is less biased than Fox this year.” Fox slapped back: “This is nothing more than Newt auditioning for a windfall of a gig at CNN. That’s the kind of man he is. Not to mention, he’s still bitter over the termination of his contributor contract.” That exchange came just days after Gingrich’s “Hannity” appearance and at the beginning of his apparent vacation/exile from Fox airwaves. But big-time news orgs don’t let a little rhetorical volley from a candidate influence their programming decisions. They’re too thick-skinned for that. It’s about the viewers, after all.