Oh brother...shooting birds is the last thing you should consider. In the case of crows they are game animals in most states and shooting them may bring more trouble then they are worth. Remember that most people like birds, even those filthy pigeons, and seing dead birds can be a big PR problem.
I have heard that Alka seltzer thing too, it is an "Urban myth", besides it tastes so bad the birds won't go near it.
There are many repellents on the market, ranging from Polybutene gels (same stuff that makes lipstick go on smoothe) to gels with a mild blistering agent. Birds do not like to stand in Polybutene gel it so putting it on the ledges they sit on will drive them off. Needle strips are used on buildings, kind of like Punji stakes for birds, but they are expensive and difficult to install. Bird nets can be used to keep birds out of areas they fly into or roost, but are expensive and difficult to install properly.
There are traps for birds, but these are difficult and time consuming to use. Helium baloons with holographic eyes will often scare of birds for a few days untill they get used to them. There is a whole line of fake owls, rubber snakes etc that are marginally effective.
The best stuff for the homeowner is the Polybutene gel, it goes on easily and does repel the birds. Downside is that it often runs and must be replaced every six months or so. One trade name is "4 the birds". It is not restricted so should be available from a local pest control company or supplier.
Poisons should not be used, as they are indiscriminate and may kill songbirds instead of the pigeons. Remember that most bird species are protected, except for Pigeons, Starlings and English (House) sparrows which are classed as vermin. Vermin can generally be dispatched without violating any laws as long as it is done humanely.
If you shoot them, get rid of the bodies before the local ladies club sees them!
So much for a short course in bird control, it is a lot more difficult that it seems.
Geoff Ross
[This message has been edited by K80Geoff (edited March 28, 2000).]