The short answer: Adult gyrfalcons typically weigh between 1.2 and 2.1 kilograms (about 2.6 to 4.6 pounds), with females noticeably larger and heavier than males.
Gyrfalcon weight by type
As the largest falcon, the gyrfalcon shows a clear size gap between the sexes. Here are typical figures.
| Type (example) | Typical weight |
|---|---|
| Adult male | About 0.8 to 1.3 kg (1.8 to 2.9 lb) |
| Adult female | About 1.4 to 2.1 kg (3.1 to 4.6 lb) |
| Large female | Up to roughly 2.3 kg (5 lb) |
| Fledgling | Roughly 0.9 to 1.5 kg (2 to 3.3 lb) |
What affects gyrfalcon weight
- Sex. Females are much heavier than males, a strong difference even among falcons.
- Age. Birds reach near-adult weight after fledging but body condition continues to vary.
- Feeding. A recently fed bird carries extra weight in its crop.
- Season. Body condition shifts with prey availability in the Arctic.
- Population. Birds from different regions and color morphs can differ slightly in size.
How gyrfalcon weight compares
A large female gyrfalcon at around 2 kg weighs about as much as a bag of sugar or a small house cat kitten.
Frequently asked questions
Why are female gyrfalcons heavier than males?
Reversed size difference is common in birds of prey. Female gyrfalcons can weigh roughly 50 percent more than males, which helps with incubation and defending the nest.
Is the gyrfalcon the largest falcon?
Yes. The gyrfalcon is the largest falcon species in the world, both in length and weight.
How much does a gyrfalcon weigh compared to a peregrine?
A gyrfalcon is heavier. A large female gyrfalcon can weigh over 2 kilograms, while a peregrine falcon usually weighs under 1.5 kilograms.
