Starlings can be excluded from entering nestboxes boxes by using the correct size entrance hole, but will out-compete bluebirds for woodpecker holes and other natural nesting cavities.During the summer, bluebirds feed mainly on insects. In the winter, they depend on wild berries.
1. (Geological Science) (of sedimentary rock, etc) composed of fragments of pre-existing rock that have been transported some distance from their points of origin. 2. (Biology) biology dividing into parts: a clastic cell. 3. (Medicine) able to be dismantled for study or observation: a clastic model of the brain.
The most common clastic sedimentary rocks are breccia and conglomerate (formed from gravel), sandstone (from sand), siltstone (from silt), and shale (from clay). B. CHEMICAL SEDIMENTARY ROCKS. Chemical sedimentary rocks are crystalline, that is made of crystals interlocked with each other.ediment is a general term that indicates loose grains (such as the sand at the beach) and chemical precipitates (such as crystals of salt). Sedimentary rocks can be subdivided in three categories: clastic, chemical, and biochemical sedimentary rocks.