Over the last year or so, I've been observing house sparrows, because they are so prevalent in the northeast US cities. I noticed that a lot of sparrows, even in different cities seem to have very similar body language for communicating. I learned 3 expressions
Here's an example of a sparrow feeding their young. The young bird opens month and flickers its wings in what I can only describe as impatiently.
A sparrow swipes its beak along a surface at its feet - something food related?
A sparrow fluffs its feathers, turning into something like a tennis ball made of feathers.
I'm looking at this video of a sparrow raised in captivity, and it does 2 out of 3 expressions described here.
What interests me is if expressions like these are "local dialects" or universal, thus found across different geographies and times? for example, do sparrows in northeast US use the same expressions as sparrows in Australia? What about sparrows in the United Kingdom in the 1950s?