Yesterday this was day 17. Too early to hatch.
Therefore I think it must have been something like Altairsky presumed. A heavy clumsy broody or the shell may have been to weak.
Flocks (social structure of chickens) and colonies (above) are not the same thing. Colonies of birds gather specifically to breed and raise young together for better predator protection, or simply because that's where the best nest sites are and where food is available. Flocks live together all year round, not just when nesting and raising young. I don't have a specific source for this except I've watch a lot of nature shows throughout my life, so feel free to fact check and correct me if I'm wrong. The distinction is needed because it's a completely different social structure.
I recently watched the same video here's the link:I know @Shadrach wrote an article about the egg song being an escort call which I found really interesting. I'll have to reread it soon because most of the info has fallen out of my ears
So I don't remember if this was touched on in the article but I watched a video recently (I don't have the link) where the person stated that the egg song is an invitation for other hens to lay on her nest, so that she can incubate and hatch them.
The discussion of whether a hen will accept chicks that aren't hers reminded me of that. Does anybody have any thoughts on this?
True, and a useful distinction.
That I'm not so sure of. The more I read in ornithology, the more I realize that there is a lot more variety and fluidity in avian lives than was thought or taught in times past. And that things can change/ evolve much more quickly than anyone guessed - within as short a time as 3 generations, which for a lot of bird species is less than a decade. Distinctions, I find, are useful when they serve as guides, not as rules.
I have much experience with mixed flocks and broodies; and for homogeneous birds though there only in the limited sense of some birds within the flock being the same breed and appearance as each other, but not the rest of the flock.
Right as far as I know. We share the same experience.
I have no idea about other birds than chickens. But chickens don’t seem to care about color or size of their ‘offspring’. Must say I never had a complete flock of the same colour and breed.
or dragons 
? Hopefully they eat them before they get eaten.
That's interesting . .makes me wonder if there were chicks and ducklings in the clutch if the chicks would try to follow the ducklings into the waterRight as far as I know. We share the same experience.
I have no idea about other birds than chickens. But chickens don’t seem to care about color or size of their ‘offspring’. Must say I never had a complete flock of the same colour and breed.
I had all kind off eggs under my broodies. The broodies hatched larger eggs, got larger chicks, different look and getting a very different pattern a few weeks after hatch. After a few months the Amrocks got much larger in size, but the 2 broodies kept mothering their adopted eggs/chicks/juveniles.
Some people even had broodies who hatched ducks and raised them. Read it somewhere here on BYC. The hen panicked when the ducklings went into the water the first time. She waited nervously at the borderline till the ducklings got out. After this, it became a routine to follow the ducklings to the water and wait patiently until they came back on land.
I wonder what broody hens would do if they hatched reptiles
PS found a video on youtube. It was on the Belgium National news 8 years ago. The man tells: “a hunter found a nest with warm eggs beside the water where a farmer just mowed. There was no mother in sight anywhere. Thought it were pheasant eggs. He asked if I had a broody to hatch them. See how she acts.
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That's a good point. Most documentaries on bird breeding colonies don't cover anything beyond the rearing of chicks. The colonies could break off into family groups or separate unrelated flocks.
