Environmental Science: Global Owl Project

           I attended a training on how to construct artificial nestingboxes for Burrowing Owls. The training was led by David Johnson from the Global Owl Project. The first artificial nesting boxes (1977) were just that, plywood boxes with tunnels that had a 90 degree angle in them. They worked, but had issues with water seepage, inability to maneuver easily and no way to see if they worked. Mr. Johnson’s design uses flexible 6” drain line (10’ long), half of a 55 gallon barrel, hardware mesh (3’x4’), a tube of liquid nails, and two Letica 3 ½ gallon buckets. Since the liquid nails needs to be spread on so thick, he recommends leaving it to dry for three to four days. These nests should last 10 years and as long as you do not clean them out, the owls should return again and again.

Two nests should be placed within about 6 feet of each other to allow the owls a choice as to which site they want and also to give an additional escape location for the 4-8 young that might be hatched. Since February and March are the nesting and hatching months, nests should be placed in January. It’s important to watch the slope of the nesting box when placing it. The ground needs to be level and about a foot above the groundwater table but at least two feet deep for insulation. The metal mesh should be placed in the ground first to ward off gopher and pocket tortoises and other burrowing ground critters, and then the floor needs to be layered with three-four inches of softer sand for the owls to dig into for the nest cup itself.

Mr. Johnson suggested adding soil to the top of the blue barrel first, then the lid of the black bucket to secure the nest before filling in the hole carefully and tightly with the displaced soil. The black drain line should rest in a gently upwards curving arch with the mouth on the surface of the ground and the inside of the pipe lightly packed with sand to give the birds something to walk on. The area around the mouth of the pipe should be cleared in a 4’x4’ swatch and rocks or broken concrete should be layered around the first three feet of pipe to keep dogs and coyote from digging it up. He also suggested a perch about 18” or lower for the birds to sit on be placed between the two entrances and that a cattle excluder be built if the nests were to be placed in open pasture (excluder is a welded stand of metal 15-18” high that keeps cows from trampling the tunnel).

Things to remember are that nests need to be in open areas away from buildings or power lines and trees; any place hawks and crows may sit. The nests need to be a minimum of 100 yds. From buildings, 300” from the tree line, and about 150” from each other. Loose colonies of four-six pairs of birds will defend each other from predators and increase the survival of the young. He also said if you install a camera (infrared) to make sure it doesn’t click when the motion sensor goes off because it will drive the birds crazy and they will leave.