Origin of “for the birds” (Trivial; worthless; only of interest to gullible people.)

Question

I really have looked, but the best I can come up with is this

To say that something is "for the birds" is to call it horse manure. Dating from the days of horse-drawn traffic, the expression is the answer to a child's question: "Mommy, what's all that stuff in the street?"

Perhaps I need to get out more (not that there's much of it around where I live), but I find it hard to believe that of all the things it might be known for, bird food should be considered an archetypal use for horseshit. Is that really the origin?

Answer 1

From Phrases, Cliches, Expressions on www.joe-ks.com:

For the birds

Meaning: Something that is worthless.

Origin: Before the advent of cars, one could see and smell the emissions of horse-drawn wagons in New York. Since there was no way of controlling these emissions, they - or the undigested oats in them - served to nourish a large population of English sparrows. If you said that something was for the birds, you're politely saying that it's horse crap.

Example: His apology, after his deliberate and harmful actions, was for the birds in everyone else's eyes.

...and then there are the following two quotes from the Bible which if interpreted the same way, would put the usage way before the 20th century:

Isaiah 18:4 For this is what the Lord has told me: “I will wait and watch from my place, like scorching heat produced by the sunlight, like a cloud of mist in the heat of harvest.” 18:5 For before the harvest, when the bud has sprouted, and the ripening fruit appears, he will cut off the unproductive shoots with pruning knives; he will prune the tendrils. 18:6 They will all be left for the birds of the hills and the wild animals; the birds will eat them during the summer, and all the wild animals will eat them during the winter.

Jeremiah 16:4 They will die of deadly diseases. No one will mourn for them. And they will not be buried. Their dead bodies will lie like manure spread on the ground. They will be killed in war or die of starvation. And their corpses will be food for the birds and the wild animals.

(from the website: 10000birds.com as an answer to the question, "Why is 'for-the-birds' a bad thing?")

Answer 2

According to the Phrase Finder,

It is US Army slang and originated towards the end of WWII … a shortened form of the vulgar version 'that's shit for the birds'. That suggests the derivation of the phrase which is the habit of some birds of pecking at horse droppings (a.k.a. road apples) in order to find seeds. Both versions were defined in an edition of American Speech from 1944:

That's for the birds. It's meaningless

Shit for the birds. Nonsense, drivel, irrelevant matter.