On September 7, 2004, two project researchers captured a hatch year male hummingbird that was distinctly different than the hummingbirds commonly seen during the fall. They first thought that they had found a black-chinned hummingbird (Archilochus alexandri), a species present in some parts of western and southern Colorado but previously sighted only once in the park in 1973 . The bird, judging by its size and plumage characteristics, was clearly a member of the genus Archilochus, but it differed in appearance from hatch year black-chinned hummingbirds. Could it be the other member of the genus, the ruby-throated hummingbird (Archilochus colubris)? To allow further study after the bird's release, the researchers quickly took detailed measurements and many pictures of the bird. Technical features of wing and tail feathers of young birds are used to separate species so they were especially careful to “capture” these with their digital camera before banding, feeding and releasing the bird.
Their attention to detail paid off when two nationally-recognized hummingbird experts confirmed the identity of the bird as a ruby-throated hummingbird, a species not previously observed in the park. (Birding records for the area actually extend back to 1903, twelve years before Rocky Mountain NP was established.) Ruby-throateds are very rare visitors to Colorado with only about seven records in the state, although a few recent observations, including this one, are pending review by the Colorado Bird Records Committee.
Since this was a very young hatch year bird, likely fledged two or three weeks earlier, where was its home nest? The nesting area for ruby-throateds is primarily in the eastern US and Canada. However, nesting birds have been documented as far west as Montana, Alberta, and Saskatchewan. These birds are thought to migrate in a southeasterly direction, continuing on to the Gulf Coast, but some of the western birds may take a shorter route to wintering grounds, heading due south to Mexico. It is likely that this bird was one of those.
Perhaps young ruby-throateds wander this way more frequently than the records would indicate. After all, without a bird in the hand, it can be extremely hard to definitively identify young hummingbirds to species.