The Sparrow Shield has been successful in deterring invasive House Sparrows from using Eastern Bluebird and Tree Swallow nest boxes when installed on boxes still unclaimed by the sparrows. Our native cavity-nesting songbirds will adapt to the shield and still use the nest box; whereas invasive House Sparrows do not like the movement of the lines or their feathers being brushed by them. House sparrows tend to avoid having to fly between the 4 vertical, weighted lines hanging from the "halo." This passive device has 4 heavy duty, twisted, yellow plastic lines weighted with 0.5-ounce ultra steel and hanging from an aluminum metal ring suspended above the nesting box roof by a cedar bracket. The thick plastic lines are an improvement upon previously used weighted, free-hanging monofilament or fishing line to address concerns about potential bird or predator entanglement. Sparrow Shield Installation Guidelines & Timing: Mount the wooden bracket to the top of the nest box with the two provided screws. Insert the ends of the aluminum metal ring into the two nest holes in the wooden holder. The lines should naturally hang straight down. There should be a clear path to the entry hole of the nest box. For best results, install the Sparrow Shields on bird boxes that have not yet been discovered or claimed by House Sparrows. Once a House Sparrow has located a box, a Shield is much less likely to deter them. Keep in mind, Shields may not always succeed in every situation, as their effectiveness can vary depending on factors like the size of the local population of House Sparrows and the intensity of competition for nest sites in your area. Occasionally, a very persistent male House Sparrow will thwart it. If you're exploring passive House Sparrow control methods, we hope you try the Sparrow Shield! Note: Nest box NOT included. Dimensions: Halo width: 16" Halo depth: 14" Cedar Mounting Bracket: 5.5" W x 8.5" H Weighted Line Length: ~18" Included Screws Length 1.5" Made in the USA.
