This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the brown creeper.
Tucked within the bark crevices of mature conifers and cottonwoods are life forms concealed from our eyes, but not from those of the brown creeper. Either dormant in winter or active in summer, insects and spiders are hiding in bark in stages of development from egg to adult.
In this environment, the methodical and thorough searches of the brown creeper uncover food missed by more active birds. On short legs with long, curved claws, the small creeper hops in spirals up the trunks of trees. Using its long stiff tail as a brace, it stops to peer into the bark and uses its long, thin, curved bill to extract the food it finds. The creeper lives in an upward pursuit of bark-dwelling invertebrates.
In our area, the brown creeper is a year-round resident of mature forests with large trees having deeply furrowed bark. Those birds that live at higher altitudes may move downslope in winter and show up at bird feeders on trees to eat suet or seeds.
This creeper needs both live trees for foraging and dead or dying ones for nesting. The female builds a hammock nest built of twigs and bark shreds held together by spiderweb silk. The hard-to-find nest is tucked behind a loose flap of bark on a dead tree. After logging, the presence or absence of brown creepers may be used to gauge the health of the forest left behind. Dead and dying trees are essential for this bird and for many cavity-nesting species.
The cryptic plumage streaked in brown and buff that the brown creeper wears on its back provides amazingly effective camouflage. Its white belly is typically pressed against the bark. When threatened, the brown creeper spreads its wings against the tree, remains motionless and disappears against the bark.
Although the high-pitched, soft songs and calls of the brown creeper are beyond the hearing range of many people, sound identification cellphone apps can help in locating this common but often hard-to-see bird.
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