Size
Male swans are typically larger than females. The average weight of a male swan is between 12 and 15 kilograms (26 and 33 pounds), while the average weight of a female swan is between 8 and 10 kilograms (18 and 22 pounds).
Neck Length
Male swans also have longer necks than females. The average neck length of a male swan is between 1.2 and 1.5 meters (4 and 5 feet), while the average neck length of a female swan is between 1 and 1.2 meters (3.3 and 4 feet).
Head Shape
Male swans have a more rounded head shape than females. Females have a more pointed head shape.
Bill Size
Male swans also have a larger bill than females. The average bill length of a male swan is between 10 and 12 centimeters (4 and 5 inches), while the average bill length of a female swan is between 8 and 10 centimeters (3 and 4 inches).
Color
In most species, male swans are all white, while females have a dark brown or gray body with white wings.
Behavior
Male swans are more aggressive and territorial than females. They will often defend their territory from other swans and animals. Females are more docile and submissive.
Conclusion
By using the above criteria, you can easily tell the difference between male and female swans.