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Coordinator notes: Your picture taken in Montezuma County is an Old World Swallowtail. In the western U.S. including western Colorado there are three different forms of this butterfly. Two are mostly black, one is mostly all yellow (which in this group is Bruce's Swallowtail). The one in your photo is one of the two black forms (obviously), the common name would be either Baird's Swallowtail or the Western Black Swallowtail (not the Eastern Black Swallowtail). It has a spotted abdomen you can clearly see in your photo. The other black form is Holland's Swallowtail. It's abdomen is yellow and black, sometimes with spots also but the bottom and sides of the abdomen must be yellow for it to apply to Holland's (and it is a rarely seen form). The yellow form is always less common southward (such as in southern Colorado). It looks very much like the Anise Swallowtail (Papilio zelicaon) with a very yellow colored abdomen. This is a sighting that is submitted very often so thanks for the observation and time to post it. Mike