When I was looking out the window recently, a little bird climbing on the burr oak caught my eye. A Brown Creeper! Although not rare in this region, neither are Brown Creepers (Certhia americana) common birds and I was pleased to spot this individual. As their name suggests, these wee birds creep up the trunks of trees, typically starting at the bottom and working their way up the trunk before flying on to the next tree and starting at the base again.
Creepers prefer mature forest habitat with trees of large diameter, so are not at their most abundant in the agricultural lands of southern Ontario. The population hot spots are Algonquin Provincial Park and Quetico Provincial Park and forested regions to the north. Trees with strongly furrowed bark are preferred for foraging. They probe the crevices for insects and spiders and other tasty, nutritious morsels. The cryptic colouring of creepers helps them to blend right in with the tree bark. In fact, they use their camouflage pattern when pursued, landing on a tree trunk and flattening themselves against the tree, wings spread and motionless.
In breeding season, the female builds her hammock-like cup nest in a gap between the trunk and a flap of loose bark on a dead tree. The male feeds the incubating female. The young can creep up trees from the time they are mobile. Fledglings will roost together in a tight circle, heads to the center. In Ontario, the Brown Creeper population appears to have been stable in recent decades as recorded in the Atlas of the Breeding Birds of Ontario.
Willow House Chronicles 
I had a brown creeper on the maple outside my office window yesterday while I was on the phone. The naturalist in me wanted to interrupt the guy on the phone with “oh – there’s a brown creeper!” but the professional in me knew that that really wasn’t the thing to do, so it remained my little secret. Neat little birds.
Well, brightened up your conversation, even if your telephone partner didnt realize it.
Nice shot of the decurved bill, which isn’t always apparent in the birds’ constant climbing.
I didn’t know that about the chicks; I would love to come upon a knot of roosting fledglings!
A kindly friend of mine once told me about how he had walked quietly up to a Creeper and actually touched it before it flew away. His theory is that Creepers may be a little too confident in their camouflage abilities.