Not sure about density, but birds that aren’t adapted to water don’t produce the oil and don’t have the interlocking feathers to trap air and make them float very well. And you’ll find plenty of rescue videos of birds struggling to get out of water they’ve accidentally ended up in, e.g. owls, pigeons.
Is there a bird too dense to just float?
Like I think penguins even float don’t they?
Maybe dodos
Not sure about density, but birds that aren’t adapted to water don’t produce the oil and don’t have the interlocking feathers to trap air and make them float very well. And you’ll find plenty of rescue videos of birds struggling to get out of water they’ve accidentally ended up in, e.g. owls, pigeons.
Most birds can float because they have hollow bones and waterproof fearhers, making them pretty buoyant