Don't you get tired of making these stupid and easily refutable lists?
How do birds know how and when to build a nest?
Various cues such as day length and light angle for when, instinct for where (the best nest builders had babies that survived, the worst nest builders' babies died)
How do they choose who to hang with?
A variety of factors, depending on the species. In some species, males with the biggest number of different songs are the sexiest, it shows they're strong birds. Basically there are lots of different ways for birds (and other animals) to demonstrate that they'll be able to take care of the mate and the babies for the duration.
How do they recognize old friends (they all look the same)?
Just like all *insert non-white "race"* look the same right? If they're in close contact with them they recognize their friends, their family, their enemies and rivals.
Why don't we see fat sparrows?
Fat sparrows get eaten because they're slower to escape predators. Fat humans or pets don't have to try to escape predators.
What are they singing about?
It's just a mating call, generally. Or a territory call. Or a mommy come feed me call. Or. . .
Who teaches them music?
There's a sensitive period in which their brain is very open to learning songs of their species. If they're denied access to at least recordings of species specific calls they're "musically" crippled for life.
How come they can all sing on key?
See above.
How do they know that they are sparrows so that they can hang with other sparrows?
They can see, idiot.
Birds of a feather do flock together (how many sparrows do you see flying with seagulls?).
Sometimes birds of different feathers flock together. I helped rescue a fledgling blue jay from a crow, with the help of its parents, a sibling from the prior year, AND a pair of MOCKINGBIRDS.
Are they nervous on their first flight?
Who knows? Nervous as an emotion we can't ask them about. Nervous as a chemical process is hard to test in that situation.
Who warns them about cats?
Other birds, sometimes even of different species! They're capable of learning the warning calls of not only their kind, but other kinds as well :O!
If it's their mom and dad, how do they communicate with their kids?
God, you're an idiot. They have voices you know. They learn what the different calls mean when they're very young. Or they get eaten.
Do they dream?
Who knows? Do birds go into REM sleep? I think other animals do, not sure about birds.
What do they dream about? Cats?
How the hell are we supposed to know? We can't ask them.
If they think, do they think in English or Chirp? Probably Chirp.
Uhm. I can't answer whether or not they think. If they did think, then yes it would be in their own language. They aren't equipped for English. Question for you. If a person is born in China, and s/he's taught Chinese, do you think s/he thinks in English or Chinese?
Are they taught language skills while in the nest or afterwards at some sort of hidden Chirp school?
Again, see above. And read a fucking introductory animal behavior text.
Does the language have a similar structure to human language?
No.
When they all get together for a sing along (we often hear loud tree choirs), do they have a conductor? Is anyone is charge, or is it just a jam session of golden oldies?
A "sing along" is probably a contest among suitors for a female, a territory fight, or similar things important to birds. They're not "singing along" they're trying to outdo each other.
And now to our regularly scheduled presumption of how people you can't possibly know how they think, think:
"As an atheist it must be a little frustrating having no one to thank for all this."
No. I do not feel a need to thank anyone for the world. To be completely honest I'd rather curse whoever put me in it if there was someone bigger responsible (which there's not) for making me so fucked up.
"How can you not stand in awe at the intelligence of the mind that put all this together?"
Forget the intelligence crap. You know what I stand in awe of? The full moon. The sound of a forest in the breeze. The power of a violent storm. The regenerative process of a habitat that's been destroyed by a natural disaster. The instincts and abilities of animals. The love many animals are capable of giving. The hate many human animals are capable of giving. The sheer variety of things living in the world (1200 kinds of bats and 1500 kinds of rodents alone). The power of a well-adapted predator. The ingenuity of many potential prey animals.
Intelligence has nothing to do with it. Why should an intelligently designed predator have to stop pursuing its prey because it's too hot? Why should an intelligently designed predator have to leave its kill for kleptoparasites because it has given up all its fighting abilities for pure speed? Why should an intelligently designed predator chase one particular prey animal single-mindedly while it runs past others of the same species that escape simply by standing still? Why should an intelligently designed predator have to give up climbing ability for speed? Why should an intelligently designed predator have to always use a suffocating throat bite because its canines are miniscule and incapable of severing the spinal cord of all but the smallest animals? Why should an intelligently designed predator have to abandon its young because it only had one or two and the tradeoffs the mother has to make for the young isn't worth it until she bears at least 3?
Don't get me wrong, cheetahs are REALLY awesome animals, but how can you look at them, ALL of them, and honestly tell me there's intelligence behind their many shortcomings? You want me to go through the rest of the cats? How about the extinct sabertooths whose canines would snap if the prey struggled or they hit the wrong spot? Shall I start on other groups of animals? You want me to start into the plants after that?
"I marvel at the genius of God. He sees the meal but never tastes it...because he doesn’t want to. What a tragedy."
I don't have to marvel at something that doesn't exist. It's not a matter of want to either. If I could believe in God it sure would save me a lot of heartache and anxiety, but I just can't.