The most reliable way to distinguish between male and female white-bellied sea eagles is by their size. Females are slightly larger than males, with an average length of 80-90 cm (31-35 in) and a weight of 2.5-4.5 kg (5.5-9.9 lb), while males have an average length of 66-80 cm (26-31 in) and a weight of 1.8-3 kg (4.0-6.6 lb). This size difference may not be easily noticeable when the eagles are seen individually, but becomes more apparent when they are observed together.
Size Differences Between Male and Female White Bellied Sea Eagles
| Characteristic | Male | Female |
|---|---|---|
| Average Length | 66-80 cm (26-31 in) | 80-90 cm (31-35 in) |
| Average Weight | 1.8-3 kg (4.0-6.6 lb) | 2.5-4.5 kg (5.5-9.9 lb) |
Behavioral Differences During Courtship
Image source: bellied sea eagle by shankar s
Another way to differentiate between the sexes is by observing their behavior during courtship. White-bellied sea eagles engage in various aerial displays, including circling, chasing, diving, somersaulting, and cartwheeling with their talons locked. These displays occur throughout the year but become more frequent during the breeding season. Once a mate is found, white-bellied sea eagles typically remain with that mate for life, but if the mate dies, they will find another.
Physical Characteristics of White Bellied Sea Eagles
In terms of physical description, white-bellied sea eagles have a distinctive appearance. They have a white head, rump, and underparts, with a dark or slate-grey back and wings. When viewed from below, the black flight feathers on their wings are easily visible. The large, hooked bill is a leaden blue-grey with a darker tip, and their irides (eyes) are dark brown. The cere (the area between the bill and the head) is also lead grey. Their legs and feet are yellow or grey, with long black talons (claws).
Juvenile Plumage Differences
Juvenile white-bellied sea eagles have a different coloration than adults, with predominantly brown plumage and pale cream-streaked plumage on their head, neck, nape, and rump areas. The plumage becomes more infiltrated with white until it acquires the complete adult plumage by the fourth or fifth year.
In conclusion, the most reliable way to distinguish between male and female white-bellied sea eagles is by their size, with females being slightly larger than males. Their behavior during courtship, physical characteristics, and juvenile plumage can also provide clues to their sex, but size remains the most accurate indicator.
References:
– Wikipedia – White-bellied Sea Eagle
– Animal Diversity Web – Haliaeetus leucogaster
– Birds of the World – White-bellied Sea Eagle
