bowhunting coyotes in my book is the ultimate challange,it can be done but most likly will be the hardaest thing you have ever done in the hunting woods.as far as a light goes,if its not real intense and its covered with a red or amber lens(red is better)it will not spook them.if your thinking of trying this alone then your problably wasting your time.it is best to do this with a partner,he does the calling and you(the shooter)sits down wind.the only way this might work by yourself is with a remote eclectronic caller.again a tree stand might work good if a caller is up wind and you are not sky lined in any way.not being sky lined up a tree in the winter months is nearly impossible.when a coyote is responding to a distress call his sences are extremly tuned in,he will most likly pick your outline in a tree long before being in range.a ground blind(be it natural or man made)might be the ticket here.this will give you important cover when making a draw.just make sure the blind blends in naturalyone final note,you might want to check your game laws about putting a light on your bow.or even using a bow at night.there maybe restrictions in place.