I have good news for lawmakers looking to purge wasteful spending from the federal budget: It’s a target-rich environment out there.

That’s not to say you won’t encounter pushback from special-interest groups bent on preserving their slice of the pie. But a quick tour of the latest “Wastebook” from Sen. Jeff Flake, Arizona Republican, shows they don’t have any kind of credible defense.

Let’s sample a few of this year’s most egregious examples:

• Singing dinosaurs. You’ve probably never wondered if the scaly creatures in “Jurassic Park” could warble a tune. But just in case, the answer appears to be they couldn’t have, thanks to a study partly funded by grants from the National Science Foundation totaling $450,000.

• Religious aliens. Say we find life on another planet. How might the world’s religions respond? Perhaps you consider that a good question, but I’m hoping you agree that NASA’s Astrobiology Program had no business giving more than $1.1 million to the Center of Theological Inquiry to find an answer.

• Fish treadmill. Getting yourself to the gym is hard enough, but how about the occupants of the nearest aquarium? The U.S. National Science Foundation gave $1.5 million to the University of California-San Diego to find out how long mudskippers (fish with the ability to live out of water for certain periods of time — ones with fins they use as “legs”) could use a treadmill.

• Hologram comedy club. We all enjoy a good joke, but taxpayers probably won’t be amused to learn that the U.S. Commerce Department gave $1.7 million to the National Comedy Center to build a museum in Jamestown, N.Y., that will feature holograms of dead comics performing.

• Shark soundtrack. You might think sharks get their bad reputation solely from their snapping jaws. But according to a $3 million study funded by the National Science Foundation, part of the blame goes to John Williams, who composed the soundtrack to “Jaws.” Yep. That “Da-nuh, Da-nuh” theme made people more afraid of those poor predators.

• Fear-of-dentists study. Why are people afraid to go to the dentist? Another “duh” question, another huge grant: Researchers at West Virginia University got more than $3.5 million from the National Institutes of Health to ponder dental phobia. “Fear of pain has been shown to be a critical component,” they note. Gee, why didn’t the rest of us think of that?

• High-speed train. The Federal Railroad Administration has given California more than $3 billion over the last six years to build a “bullet train” between San Francisco and Los Angeles. And that’s only a down payment on a project slated to cost nearly $100 billion. Number of tracks built so far: zero. If Californians want to risk their money on a potential boondoggle, they should be free to do so, but leave taxpayers in other states out of it.

Why worry about reducing waste, especially in such a gigantic budget, and even more so when huge swaths of it are on autopilot and, therefore, immune to ordinary cuts?

For one thing, even relatively small amounts add up. More importantly, they reinforce the fact that lawmakers should be good stewards of every taxpayer dollar.

Should people refuse to pick up a few pieces of litter because there is a lot of trash elsewhere? Of course not. We have to start somewhere.

But there’s a bigger picture at work, and it’s summed up nicely in the Heritage Foundation’s “Blueprint for Balance: A Federal Budget for 2017.”

“Congress should use the budget process to promote free enterprise, limited government, traditional American values, and a strong national defense,” the editors note. “By reducing debt and putting the fiscal house in order, Congress can produce a strong economy, a strong society, and a strong America.”

The latest “Wastebook” is 201 pages. Let’s hope lawmakers take the suggested cuts to heart and help make next year’s edition much shorter.

Before we put the “Wastebook” out of print entirely, that is. Can we do it, Congress?