Results of 2012 Bluebird Box Usage

Tree Swallow perched on Bluebird box

Female Bluebird
Photo by Bob Stanowski












In the beginning of August all Bluebird boxes on White Memorial property were opened, inspected, and cleaned out. Unfortunately Bluebirds had a difficult breeding season, resulting in a 41% success rate. Weather was mostly to blame for this low percentage. Bluebirds start to lay their eggs in mid-April; and as some recall in the beginning of May this year we had lots of rain with unseasonably cold weather. This combination of cold air with damp conditions proved to be too overwhelming for the eggs and chicks; this became evident when we discovered many dead chicks and abandoned eggs. However Tree Swallows, who also use the boxes for nesting, had a positive season, with an 81% success rate, occupying most of the boxes. There were also twelve House Wren nests, half of which were constructed on top of Bluebird or Tree Swallow nests. Male House Wrens are aggressive and will destroy the eggs and young of other birds in order to use the nesting area. House Sparrows will also evict any nesting bird to take over the site, although only three House Sparrow nests were found in the boxes. House Sparrows are less tolerated around Bluebird boxes than House Wrens because House Sparrows are invasive species. First released in Brooklyn in 1851 from Europe, House Sparrows have become one of the most abundant and widespread songbirds in North America. Other unwelcome wildlife includes paper wasps found in five boxes and a White-footed Mouse in one box. In conclusion, 72 out of the 76 Bluebird boxes were active; meaning that a bird at least attempted to build a nest there, and of these 72, 70 were actually used to raise chicks.     

House Wren nest with six chicks inside stacked on top of a Bluebird nest

Bluebird Nest Box Spring Inspections

Adult male Tree Swallow photo by

Bob Stanowski

Adult female Eastern Bluebird photo by

Bob Stanowski

Photo by Dave Rosgen of WMCC volunteer

Jim Kandefer opening a bluebird nest box

for inspection in the Bantam R. Field

The Connecticut Bluebird Restoration Project currently maintains 78 bluebird nest boxes on White Memorial Foundation property in Litchfield and Morris. We monitor them regularly from mid-March through mid-October, with the first and last inspections of each year focusing on addressing maintenance needs and performing vegetation management. Fortunately for us and the birds, most of the nest boxes are less than 5 years old, and, thus, don't require much maintenance work. Just like anything else, as the boxes age, they require more maintenance. Eventually, it gets to a point where it is no longer practical to continue repairing an old box, and it is replaced with a new one. This usually happens when a box is between 12 and 15 years old. We are able to achieve such long life spans by using high quality white pine lumber for all of the component parts of the nest boxes, fastening the parts together with 1 5/8" drywall or deck screws (never nails!), and by caulking the seams between the back and sides and top and sides. This technique has proven to be very effective in keeping moisture out of the boxes, which, in turns, keeps them from rotting prematurely. All of the poles are fitted with hardware cloth or aluminum flashing mouse guards as a cap over the PVC pipe predator guard (which is essential!) that encircles the pole on which the box is mounted. Mice can ruin a nest box in one season, so it is extremely important to keep them out. Ice and snow can take more of a toll on nest boxes than rain, so it is really important to check them in March in order to repair winter-caused damage. So far this spring we've been lucky. Out of 24 boxes inspected in the past week, only 2 needed to have component parts replaced. In both cases, the front door was split; probably from moisture entering cracks and then freezing. We also found one old wooden pole to be rotted. That will be replaced very soon with a new metal pole. Over the past few years we've been transitioning away from wooden poles to metal ones because the metal ones last so much longer. We also found one pole at a 45 degree angle, and straightened it back up. This might have been caused by a buck White-tailed Deer sparring with it last fall. While checking the boxes we were pleased to see a pair of Eastern Bluebirds back on territory in each of the fields, and a group of 8 newly-arrived Tree Swallows in the Alain White Rd. field. These maintenance inspections will probably continue for another 2 weeks, until all of the boxes have been visited, and until any problems that are encountered are corrected.