Understading Raptor - White-Bellied Sea-Eagle (Part 2)

Aging is Sea Eagle is documented making the common species age gap poorly classified. In this article here we will attempt to show the difference of each age class follow by some picture for further assistance.

The Juvenile 1 year eagle show mainly brown in plumage. Underpart body show clearly a lot of brown. Most importantly the flight feather also show dark brown with buff to brown wing covert. Tail pattern distinctive showing dark terminal and pale sub terminal band a marking crucial in identification of age in later year. Darker marking in breast is distinctive to 1 year bird.

White-Bellied Sea Eagle
(Photo by Terence Ang)

The 2nd year bird show a slightly different in plumage. While remaining a lot of the underpart plumage, flight feather show clearly in moult especially in P2,P3,P4.  Tail marking began to moult. Majority of other plumage remain as in 1st plumage. See this photo below.

White-Bellied Sea Eagle
(Photo by Terence Ang)

White-Bellied Sea-Eagle
(Photo by Terence Ang)

3rd Plumage bird can be differentiate from the tail. See this photo here. The terminal is now replace by broad white band. New feather on P5 plumage. At least 85-90% of bird maintain clear dark breast area. Wing panel visible at least till 4th year.

4th Plumage show almost adult plumage. Majority of times easily mistaken as adult in perch. In flight however the white on inner primaries is visible. Other part as in adult.

White-Bellied Sea-Eagle
(Photo by Terence Ang)

5th plumage onward are the adult plumage. This species in this plumage is unmistakable. Majestic of the air the clear black and white plumage will catch many birder eye without fail.

White-Bellied Sea-Eagle
(Photo by Terence Ang)

White-Bellied Sea-Eagle
(Photo by Terence Ang)

Nevertheless I would like to share this plumage with you all. This bird here show heavy moutling. Clearly the entire inner primaries show moult. Tail pattern show clearly above 3rd year. Worn off feather showed on P6 onwards. This show a more 3rd year charateristic. However in some circumstances the plumage did not coincide to 4th plumage. The bird also show darker trailing edge forming a somewhat dark bar on the edge of the flight feather. Other part of primaries show probably a suspension from 2nd year while underpart and other show clearly in 3rd and some what 4th calender year. This also did not show any new feather between flight feather and covert. This bird in fact has been identified as 3rd/4th calender year. 

White-Bellied Sea-Eagle
(Photo by Terence Ang)

White-Bellied Sea-Eagle
(Photo by Terence Ang)