Recently, the family took a kayaking tour with Michelle’s work, Rainbow Glacier Adventures, as “guinea pigs” for a pair of new guides. On the trip, we talked about the age progression of bald eagles. Eagles take about 5 years to mature to adult, white-tail-and-head bald eagles. Each intervening year, the immature eagle’s plumage patterns provide hints as to which year of development an individual is passing through.
In the stage before full adulthood, an eagle gets very close to adult plumage, but is still in transition, so it looks like an adult bald eagle that’s gotten filthy—which leads to the common term, “dirty tail.”
The day after the tour, a young eagle visited our beach in front of the veranda. It was definitely a “dirty tail.” This one almost seemed to be wearing horn-rimmed glasses as well!
A “dirty tail” immature bald eagle (Photo: Mark A. Zeiger).
Close up . . . (Photo: Mark A. Zeiger).