What is a common sign of a hawk being underweight?

A hawk that is underweight often exhibits dull or lackluster feathers, which is a sign of poor health and inadequate nutrition. Healthy hawks typically have vibrant and well-maintained feathers, as proper nutrition supports feather quality and overall body condition. When a hawk is not receiving sufficient nutrients, its body prioritizes essential functions over feather maintenance, leading to a lack of luster in its plumage. Observing dull feathers can serve as a critical indicator to handlers about the hawk's nutritional status, prompting a need for dietary adjustments or veterinary evaluation to ensure the bird's health and well-being. Other signs related to behavior, such as how often the bird preens, its performance during hunting, or aggressiveness towards handlers, may not directly indicate underweight status.