Remsen, J.V. 1975 House Wren Troglodytes aedon May 8 Barr Lake area, Adams Co., Colo.: one bird carrying nesting material to a hole on the underside of a horizontal cotton wood limb about 8' above the ground. on the east side of Barr Lake. Later a pair of Black-capped Chickadees were seen vigorously pursuing a House Wren at another stand of cottonwoods - aggressive competition between hole-nesters? Earlier in the day, a male Red- winged Blackbird was seen to dive at a House Wren which was at the edge of the marsh below the telephone wire from which he was singing.