What is the recommended type of protection for windows in a raptor's mews when free-lofting?

The recommended type of protection for windows in a raptor's mews when free-lofting is vertical round rods. This type of protection is specifically designed to prevent raptors, such as hawks or falcons, from flying into the windows while allowing for ventilation and visibility. Vertical round rods create a barrier that is effective in keeping the birds safe inside the mews without obstructing their views or causing distress.

Vertical rods spaced appropriately can deter raptors from attempting to fly through the window, minimizing the risk of injury from collisions. This method also ensures that the birds can still interact with their environment, which is essential for their well-being and psychological health.

Other options might not provide as effective a barrier or could restrict the birds' ability to see out, which could lead to frustration or stress. Thus, vertical round rods serve the dual purpose of protection and maintaining a healthy environment for the raptors.