The tufted titmouse (Baeolophus bicolor) is a small, crested songbird found across the deciduous forests and wooded suburban areas of eastern North America. These birds are secondary cavity nesters, meaning they do not excavate their own holes but rely on existing natural or artificial structures. Their specific nest location and construction provide a safe, insulated environment for raising their young.
Specific Nesting Site Preferences
Tufted titmice primarily use existing tree cavities for their nesting sites, as they cannot create them themselves. These natural holes are often abandoned sites of woodpeckers (such as the Downy, Hairy, or Red-bellied woodpecker) or naturally rotted-out sections of dead trees or fence posts. They also readily accept human-made nest boxes, which helps mitigate the shortage of natural sites caused by the removal of dead trees from wooded areas.
The height of the chosen cavity can vary significantly, ranging from a few feet to over 90 feet above the ground. However, the most commonly recorded height range is between 5 and 15 feet. The entrance hole is small, ideally around 1 1/4 inches in diameter, which helps exclude larger competitors and predators.
Natural cavities titmice select are often deep, measuring about 8.6 to 11 inches, with an entrance hole roughly 1.8 to 2.2 inches across. When using a nest box, titmice prefer a location under heavy tree canopy and may avoid open spaces. They sometimes place the box near a food source like a bird feeder. They adapt to the space’s dimensions, filling deeper or wider cavities with substantial nesting material to create a suitable cup.
Nest Materials and Construction
Once a suitable cavity is selected, the female tufted titmouse constructs a cup-shaped nest over a period that typically lasts about four days but can extend up to 11 days. The foundation is built from coarser materials, including damp leaves, green moss, dried grasses, and strips of bark. This voluminous base fills the cavity and provides the structure for the nest cup.
The smaller inner cup is lined with soft, insulating materials to cushion and warm the eggs and hatchlings. This lining often includes fine fibers, plant down, wool, and animal hair. Titmice are known for their bold behavior of sometimes plucking hair directly from live mammals. Nests have been found to contain hair from a wide range of animals, including rabbits, squirrels, dogs, and even humans.
A particularly distinctive material sometimes incorporated into the lining is shed snake skin. The function of including snake skin is not entirely clear, but it is a unique characteristic of the titmouse nest. The female may continue to add lining material, especially fur, even after egg-laying has begun, which helps keep the eggs hidden and insulated.
The Tufted Titmouse Nesting Cycle
The nesting season generally begins in early spring, with pairs inspecting potential sites as early as March. Nest construction can start in late February, and egg-laying typically commences by early to mid-April across their range. The female lays one egg per day, usually in the early morning, until the clutch is complete.
A typical clutch size ranges from five to eight eggs, though clutches from three to nine eggs have been recorded. The eggs are small, creamy white, and covered with fine reddish-purple speckles. The female alone incubates the eggs, a process that lasts between 12 and 14 days, usually beginning when the next-to-last egg is laid.
After hatching, the young remain in the nest for about 15 to 16 days until they are ready to fledge. Both the male and female parents actively participate in feeding the nestlings. Titmice typically raise one brood per season in the northern parts of their range, though a second brood is possible elsewhere.