Greenside,
There very well could be a female invitational howl. I know that a famous western caller put some labels on a few coyote vocalizations and sold em to the public. There have been studies made by educated people who claimed they figured out somewhere between 7 and 12 different coyote vocalizations. Right now I only find three or four coyote vocalizations that interest me and are valuable to those who wish to call coyotes with a howler on regular basis. The most important ones are listed above, and will call many coyotes to those who are willing to give em a serious try. The so called "warning" bark in my own opinion is not to warn other coyotes away. To me it is only a frustrated coyote that wants to come on in, senses something ain't right and stands back at a distance to bark. After you hear it a few times, you will recognize the sound of frustration in the bark. To me, the various coyote barks and howls are only different levels of anxiety or aggression being expressed. My howling technique has changed a little bit over the past few years. As the coyotes teach me more, I try to pass on what I know. The coyote most likely will never reveal ALL of his secrets to us lowly humans. /ubbthreads/images/graemlins/smile.gif