They just may be closer or more vocal from 1 night to the next,most People don't even realize there are that many Coyotes running together and usually they will howl and bark in the late evening or after dark to find each other and group up again after a long day of running around or splitting up looking for food or even after bedding down away from each other.

Some times they will be further away from where they grouped up one night then You may hear them several nights in a row at the same spot if they haven't been shot at or messed with?It should be breeding time for the Coyotes also so the Females and Males might be more vocal now also!