Determining the Age of an Eagle





Determining the age of an Eagle.
I posted images yesterday of the confrontation of Ma Berry and the Sub-adult Eagle. I received some messages and comments as to how someone can determine the age and sex of an eagle? There are lots of guides out there for determining or closely determining age by the feathers of the birds. The 4 eagles shown in this post are examples of the differences. The first eagles are newly fledged and are drab in color with brown eyes. The second eagle is the 3 year old (actually entering the 3rd year) eagle. The tail feathers have started to turn white and it is starting to show the “terminal band” at the edge of the tail, notice the eyes are turning yellow or almost all the way changed. The third eagle is a 4th year entering its 5th year. The terminal band is pretty much gone and all that remains on the head is a simple band near the eye. Lastly the full grown adult. The completely white head and tail.
Now as for the sex of birds that is more difficult or impossible without a blood test or observing behavior during mating. However, seeing two eagles together can help as well give you a good guess. First, many people assume that smaller birds are babies, which is not the case. Many birds that are just leaving a nest may appear larger than the adults because they haven’t expelled the energy for hunting and maintain some weight. Plus their feathers have grown out and do not show the wear of life. When you see two eagles together the female is typically larger than the male. In the posted images, I won’t even try to guess on the two Juveniles, but the sub-adult is more than likely a male. He was 2/3rds the size of Ma Berry, who is a big girl anyway, but he was tiny near her. The 3rd eagle, the 4th year, was larger than the full grown adult and is probably a female. The full grown adult is more than likely a male. I am speculating that it is a young pair.
The first image was made with the Tamron SP 150-600mm Di VC USD lens on a Canon 7Dii, the next 3 images were made using the Tamron SP 150-600mm Di VC USD G2 lens on a Nikon D-500, Sirui N3204X tripod and PH20 Gimbal head, processed in Lightroom CC, MindShift Gear FirstLight 20L. #WithMyTamron, #TamronImageMasters, #SiruiPro, #SiruiUSA, #MindShiftGear

2 Responses to “Determining the Age of an Eagle”

  1. Sandra E Gresham Says:

    Thank you so much for this info and great illustrations via your terrific photos. At what age do they select a mate and is there a courting season? I have had pet parrots all my life but they are companion birds..I realize wildlife is so totally different// and how little I really know! sg

    • lilybug1960 Says:

      Thank you for the kind words. They typically will select a mate when they reach full maturity, around the 5th year. The two in the post were demonstrating behavior that made me believe they were a bonded pair, possibly not mating, but bonding and preparing to mate. They could do that for the current mating season or for next year. The female with the “eye band” was probably close to being old enough to lay eggs, her terminal band was gone so the facial streak could have just been residual. Mating season will vary from area to area, but typically in the south it is around November and December, as you move farther north it will be a little later, maybe January even February. They will often be laying on eggs while they are covered in snow.

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