Volunteers from the Hungry Owl Project try to visit every occupied box in Marin County to continue our research into the lives of barn owls. We've implemented a new tool: a remote camera and monitor. This allows us to peek into the box, from the ground, to find out if the box is indeed occupied, and if so, if it is safe to go into the box. If a parent owl is on eggs, or the owlets are still very small, we do not go into the box at that time. Usually the mother owl is not roosting in the box once the owlets get to a certain age and size.
Once we have determined there are young in the box, a "hole stopper" is placed in the entrance hole of the box. This is to make sure none of the owls make an unplanned exit from the box. We gently place a ladder on the tree or building where the box is installed.
A HOP volunteer climbs the ladder to look inside the box and determine how many owlets and whether they are old enough to be banded. Each owlet is carefully brought down.
The owlets are weighed, measured and then banded. Alex Godbe and Anne Ardillo of The Hungry Owl Project are permitted to band owls under the supervision of Buzz Hull, Research Director of the Golden Gate Raptor Observatory. The handling and banding of native birds is regulated and permitted by local and federal agencies, such as California Fish & Game. A correctly sized band is selected and placed on the owlet's leg. The placing of the band does not cause any harm to the owl. Each band has a unique identifying number which we log along with the weights and measurements, the location of the box and other data. If a banded owlet is ever found, whether alive or dead, there is a national clearinghouse that the band data should be reported to either by phone at 1-800-327-BAND (2263) or electronically via a website.
Although the owls are very young and look cute and fuzzy, they can be dangerous. Not only do they bite to show their displeasure at being disturbed, but their feet are almost the size of an adult owl and they have formidable talons. Control of the legs and feet must be maintained at all times, and watch out for that beak too! Some owls are quiet and passive during the banding process, while others raise Cain screaming and hissing and biting at the volunteers. Heavy gloves are worn when removing the owlets from the box. Gloves are removed during the banding process as it is delicate work to get the band on the bird's leg.
The banding and measuring is done as quickly as possible and then the owl is placed in a pillow case, which calms it down, and laid gently in the shade while the other owlets are processed. All owls are then returned to their box one at time. The box is closed and the volunteers retreat. Many of the boxes are not easy to reach and ladders and equipment have to be carried to the box location. Some properties have multiple boxes and each will be checked.
Signs that we look for to determine occupancy of a box are owl pellets on the ground near the box, "white wash" (owl defecation) in the area, and blockage of the drain holes on the bottom of the box. We also look for scratch marks on the outside of the box created by the owl's talons when it enters the box. After the owlets fledge (the period when a bird is able to fly out of the nest), they will return to roost in the box for a period of time. As the owl enters and leaves the box a white ring forms around the entrance hole as the downy feathers of the young are powdery - almost like talcum powder. Barn owls do not build nests in the boxes. They move in to an empty box and expel their pellets inside the box. Owl pellets consist of the undigested bones and fur of prey and are regurgitated daily. Over time, these furry pellets create a kind of carpet in the bottom of the box - a soft warm rug to lay eggs upon.
Volunteers from the Hungry Owl Project try to visit every occupied box in Marin County to continue our research into the lives of barn owls. We've implemented a new tool: a remote camera and monitor. This allows us to peek into the box, from the ground, to find out if the box is indeed occupied, and if so, if it is safe to go into the box. If a parent owl is on eggs, or the owlets are still very small, we do not go into the box at that time. Usually the mother owl is not roosting in the box once the owlets get to a certain age and size.
Once we have determined there are young in the box, a "hole stopper" is placed in the entrance hole of the box. This is to make sure none of the owls make an unplanned exit from the box. We gently place a ladder on the tree or building where the box is installed.
A HOP volunteer climbs the ladder to look inside the box and determine how many owlets and whether they are old enough to be banded. Each owlet is carefully brought down.
The owlets are weighed, measured and then banded. Alex Godbe and Anne Ardillo of The Hungry Owl Project are permitted to band owls under the supervision of Buzz Hull, Research Director of the Golden Gate Raptor Observatory. The handling and banding of native birds is regulated and permitted by local and federal agencies, such as California Fish & Game. A correctly sized band is selected and placed on the owlet's leg. The placing of the band does not cause any harm to the owl. Each band has a unique identifying number which we log along with the weights and measurements, the location of the box and other data. If a banded owlet is ever found, whether alive or dead, there is a national clearinghouse that the band data should be reported to either by phone at 1-800-327-BAND (2263) or 
The banding and measuring is done as quickly as possible and then the owl is placed in a pillow case, which calms it down, and laid gently in the shade while the other owlets are processed. All owls are then returned to their box one at time. The box is closed and the volunteers retreat. Many of the boxes are not easy to reach and ladders and equipment have to be carried to the box location. Some properties have multiple boxes and each will be checked.
Signs that we look for to determine occupancy of a box are owl pellets on the ground near the box, "white wash" (owl defecation) in the area, and blockage of the drain holes on the bottom of the box. We also look for scratch marks on the outside of the box created by the owl's talons when it enters the box. After the owlets fledge (the period when a bird is able to fly out of the nest), they will return to roost in the box for a period of time. As the owl enters and leaves the box a white ring forms around the entrance hole as the downy feathers of the young are powdery - almost like talcum powder. Barn owls do not build nests in the boxes. They move in to an empty box and expel their pellets inside the box. Owl pellets consist of the undigested bones and fur of prey and are regurgitated daily. Over time, these furry pellets create a kind of carpet in the bottom of the box - a soft warm rug to lay eggs upon.