why do sparrows keep chirping even when alone?
485419
Sparrows chirp when they are alone in the hope of attracting other sparrows. In fact, you will find that once quite a few sparrows have landed at a food source, they quieten down. This is because a single sparrow is a lot more vulnerable than a sparrow in a flock. They chirp out an "I've found food" call, the other sparrows come in and the first sparrow, statistically speaking, is less likely to be eaten by a cat while it is stuffing its beak with food.
155001
Birds of a feather flock together
1162171
there may be some info here\n\nhttp://en.wikipedia.org/wiki/Humming_Birds
837581
Nobody truely knows the exact reason for this but the massive flocks are immigrant Starlings from eastern Europe and Scandinavia. The flocks form as feeding parties converge at dusk to go to a communal roost. The flock then does a communal flight around the roost site before descending (often into a reedbed). The obvious answer would be for protection but a massive flock attracts all the predators within the local area (sparrowhawks, merlins, peregrines etc) so it is possible that the risk actually increases (dependent on flock size). It could be for warmth in the roost as a cold night could kill many birds, something close proximity might avoid.
627633
The noise is a mating/signalling call.  It is meant for other crickets to hear, not humans.  When we shine light on crickets they get scared because we pose a threat.
101572
They are not making sound with their mouth but it is the sound produced by the fast movement of their wings.
479860
This happens frequently with robins during spring mating season. It sees its reflection as an invader in the territory and competition.  They rarely hurt themselves with this behavior, but it may continue for a week or so, and happen year after year.
523944
A few years ago, I did see a crow rob a nest of a young chick. Crows will steal eggs and very young chicks for food. Crows will generally chase hawks and owls out of their territory, especially during nesting season. \n\nIt is also not uncommon to see smaller birds chasing crows, especially during nesting season since the birds know crows will eat eggs and chicks.
172040
My dogs do that alot at night too.  I asked this same question on Yahoo! Answers about 3 weeks ago.  My dogs howl usually when an emergency vehicle goes by (when they hear a police siren, fire truck, ambulace, paramedics).  I think the sound hurts their ears, however, all the other dogs in the neighborhood too, so it could be the "pack instinct".
292689
On extremely cold days many birds will roost to conserve heat. If they take to the air they expose their underwings and bodies, and the short insulating feathers under the flight feathers are exposed to the cold air, so they no longer provide adequate insulation.
424159
Ravens and all birds are considered to be messengers. As I speak there are 4 outside picking up the deer corn. Do I consider this a message. No. But last year one came and sat on the top of the gazebo and wouldn't shut up. Very annoying. About an hour later the phone rang. My daughter had just been rushed into the hospital in premature labor. What's really great about the ravens is they have a plan. About 10 or more get together and each has it's own job. One takes one road and the other ones have thier own road to monitor. When one finds food, they call to the next one, which calls to the next one and pretty soon all of them are there eating. Owls on the other hand are considered messengers of death or soon to be dead. So watch those hooters. Oh, and usually if you see an eagle, a raven is not far away. Well, where I live anyway. I just answered this ? yesterday. Now as i sit here typing, there's a Bald Eagle sitting out on the ice in front of our house. And inching closer. The only thing I can figure is, the ravens were here yesterday eating. If he's bringing a messenger... This has never happened before. Maybe I should go out there. Oh...he's walking this way!! For true.
217523
Sometimes they can't afford to take care of it (they can't bring enough food to allow the chick's survival).  Othertimes they are stressed, or think for some reason the egg is 'bad', ie the chick is not alive any longer.  It's pretty common.  If the mother gets spooked, she will abandon the nest.
1135317
If it's a medium-sized, rather ugly mottled black/brown bird that congregates in the evenings to form a roost community then it may be grackles.  They have no song, just a rather raucous squawking call and when they gather by the hundreds in the trees nearby, they are a nuisance of the first order.  Much worse than pidgeons.  We have them in Texas and I believe that at different times of the year they plague most of the US.
839791
hedge sparrows and Tramps
1038234
Linguistically speaking, "chirp" and "tweet" are descriptor words - words that sound like the way they are pronounced.  With bird sounds, the "chirp" and "tweet" "describe" the sound the bird makes.\n\nHowever, when using a term that is non-descriptive, we use verbs to describe the action that the birds are doling.  In this case the closest verb reference is "sing."
160311
i have same problem i love my chirprator he uses a machine  the true name i don`t know.it`s nicknamed woodpecker or jackhammer.it works by a hand held thingy that sorta thuds inbetween vertabras & gives reading- wonderful!i have a 2disengrating dics keeps me happy had to go every week at first ,now once every 2 mos better than surgry.please check. its very safe.
19027
I think the scientific explanation is that this is a behavior trait that is hard-wired into their brains through the wonders of natural selection.  When animals are born (including people), their brains (and actually their entire physical bodies) are pre-programmed to do certain things.  They eat when they're hungry.  They "feel" hunger when they haven't eaten in a while.  They run when they're scared.  They feel scared when they see, smell, hear, or feel certain types of things.  Their hearts beat.  Their eyes blink.  They sleep when they're tired.  Having these characteristics gave them the ability to survive as a species and be around today to be observed by us.  Animals who had hearts that didn't "know" to beat automatically didn't last long.\n\nSo flying south for the winter is an instinct that allowed birds to survive.  The many birds who lacked that instinct had more difficulty surviving.