[Pseudoscience-is-malarkey (OP)]

Wrens love eating worms. But they're very bad at preserving them. Worms regenerate. So, if a wren eats half a worm, the worm will quickly grow into a full worm again. But wrens don't appear to ever do that. They always eat them whole.

[alancalverd]

How very sensible. There are more worms than wrens, and they manage to reproduce without having an external agent cut them in half.

Also very humane. The rules of kosher and halal slaughter prohibit partial dismemberment of a living animal. 

[Colin2B]

if a wren eats half a worm, the worm will quickly grow into a full worm again. But wrens don't appear to ever do that. They always eat them whole.

A worm in the crop is worth two in the ground.

[evan_au]

Birds do evolve to eat more efficiently.

Darwin noticed groups of finches in the Galapagos islands that had slightly different beaks, depending on their environment and diet.
- It is thought that these subspecies diversified from a single finch species that arrived in the Galagos about 1 million years ago.
https://en.wikipedia.org/wiki/Darwin%27s_finches

[alancalverd]

Come to think of it, there are indeed birds that practice "farming" rather than hunting.

At least one species of American starling buries nuts rather like a squirrel when they are plentiful, and returns to eat them in winter.

Some Australian crows carry burning sticks from a forest fire and set light to grassland to drive out insects and small mammals.

Wrens just happen to live in an environment where this sort of planning isn't needed.

[vhfpmr]

Wrens love eating worms. But they're very bad at preserving them. Worms regenerate. So, if a wren eats half a worm, the worm will quickly grow into a full worm again. But wrens don't appear to ever do that. They always eat them whole.

Just like humans then, they gobble up all the resources as fast as they can today with little or no thought for whether there'll be anything left for tomorrow.

[Colin2B]

At least one species of American starling buries nuts rather like a squirrel when they are plentiful, and returns to eat them in winter.

Jays also do this in uk

Wrens just happen to live in an environment where this sort of planning isn't needed.

No point burying worms 

[alancalverd]

There is a serious point lurking here.

The common earthworm lumbricus terrestris is a true hermaphrodite that carries both male and female reproductive organs at its front end. Seminal vesicles and ova are generally the most nutritious parts of an animal, so if a bird were to intentionally cut a worm in half it would preferentially release the sterile part and thus not contribute to worm population growth.

[Petrochemicals]

Wrens love eating worms. But they're very bad at preserving them. Worms regenerate. So, if a wren eats half a worm, the worm will quickly grow into a full worm again. But wrens don't appear to ever do that. They always eat them whole.

That's because they haven't got a pair of scissors, I imagine they swallow their food whole? Seabirds swallow large fish whole, and alive! So unlike you and your chopping worms in half to make more worms, wrens have a wriggly worm in their tummy.

[Petrochemicals]

Wrens love eating worms. But they're very bad at preserving them. Worms regenerate. So, if a wren eats half a worm, the worm will quickly grow into a full worm again. But wrens don't appear to ever do that. They always eat them whole.

That's because they haven't got a pair of scissors, I imagine they swallow their food whole? Seabirds swallow large fish whole, and alive! So unlike you and your chopping worms in half to make more worms, wrens have a wriggly worm in their tummy.

This didn't even get a reaction. Gull eats puffin at the end.