After the young have left the nest, remove it. Wrens won't re-nest on the old one.
Not in one where the bluebirds already are nesting, but wrens are cavity nesters, and will nest in unoccupied bluebird houses.
Wrens will typically nest 2 times per their nesting season, which is April through July. The male wren actually builds the nest of twigs and sticks, and the wren will either accept it reject it. If rejected, the male will have to build another nest.
Cactus wrens usually nest in the cholla cactus. This very spiny cactus provides protection for their eggs and young from predators such as snakes.
Bluebirds sometimes build more than one nest, as a diversion to predators.
It is very common for House Wrens to remove baby birds of other species from their nest before they get too heavy for them to pick up. Usually after about 4-7 days of development, the babies are safe from a House Wren due to their weight. House Wrens will often Take out the babies and drop them to the ground, and then either build their own nest or simply disappear. House Wrens however are a protected species and therefore they and their eggs/babies cannot legally be harmed.
House sparrows and wrens often compete with bluebirds for the same nesting house. Often time sparrows will break bluebird eggs or make another nest over the current bluebird nest.
North American Wrens which there are 9 types, are secretive. They (House Wren, Carolina Wren, Rock Wren, Canyon Wren) will nest in holes, trees and birdhouses. The Marsh Wren makes a globe-shaped nest which are attached to plants just above the water. Cacus Wren builds a nest shaped like a football in cacti.
wrens warble
Wrens are naturally completely insectivorous.
Wrens are a type of bird. Wrens can also refer to members of the former Women's Royal Navy Service. It is also a surname.
A group of wrens is called a flock or herd