What bird can be weighed using a gram scale?

The option indicating that all of the listed birds can be weighed using a gram scale is correct because gram scales are versatile instruments capable of measuring small weights accurately, which is essential for monitoring the health and condition of birds like American Kestrels, Peregrine Falcons, and Gyrfalcons.

Each of these species varies in size, with American Kestrels being the smallest among them, generally weighing between 80 to 160 grams, while Peregrine Falcons can weigh from 600 to 1,500 grams, and Gyrfalcons can weigh up to 2,000 grams or more, depending on their subspecies. Accurate weighing is critical in falconry since it allows falconers to assess the health and readiness of the bird for hunting, training, or breeding. Using a gram scale also allows for precise monitoring of weight fluctuations, which can indicate health issues or the need for dietary adjustments.

Thus, the ability to weigh all these birds accurately on a gram scale reinforces their importance in bird care and falconry practices.