_Accipiter cooperii_[C] _Coccyzus americanus_[C] _Centurus carolinus_ _Melanerpes erythrocephalus_ _Tyrannus tyrannus_ _Myiarchus crinitus_ _Contopus virens_ _Sayornis phoebe_ _Cyanocitta cristata_ _Dumetella carolinensis_ _Toxostoma rufum_ _Sialia sialis_ _Vireo olivaceus_ _Icterus spurius_[C] _Icterus galbula_ _Quiscula quiscalus_ _Piranga rubra_[A] _Passerina cyanea_ _Richmondena cardinalis_ _Pipilo erythrophthalmus_[C] _Spizella passerina_[C] [C] Breeds farther west in North America in other types of vegetation. _Influence of Riparian Woodland_ Although the largest single element of the Kansan avifauna that reaches distributional limits in Kansas is made up of birds of the eastern deciduous forest, several species of the eastern woodlands are present in Kansas along the east-west river drainages in riparian woodland; the species are listed in Table 8. Twenty-one kinds are involved if we include the Cooper Hawk, Yellow-billed Cuckoo, Orchard Oriole, Summer Tanager, Rufous-sided Towhee, and Chipping Sparrow, all of which breed farther to the west but are present in western Kansas only along river drainages. This leaves 15 species of eastern deciduous woodlands that occur west in Kansas along riparian woodland (_versus_ 30 species that drop out chiefly where eastern woodland drops out). These 15 species are about one-third of all woodland birds in western Kansas. Riparian woodland does not seem to afford first-rate habitat for most of the eastern woodland species that do occur; breeding density seems to be much lower than in well-situated eastern woodland. The importance of these linear woodlands as avenues for gene-flow between eastern and western populations, especially of species-pairs (grosbeaks, flickers, orioles, and buntings), is obviously great. Likewise significant is the existence of these alleys for dispersal from the west of certain species (for instance, the Black-billed Magpie and the Scrub Jay) into new but potentially suitable areas. BREEDING SEASONS Introduction An examination of breeding seasons or schedules is properly undertaken at several levels. The fundamental description of variation in breeding schedules must itself be detailed in several ways and beyond this there are causal factors needing examination. The material below is a summary of the information on breeding schedules of birds in Kansas, treated descriptively and analytically in ways now thought to be of use. Almost any event in actual reproductive activity has been used in the following report; nestbuilding, egg-laying, incubation, brooding of young, feeding of young out of the nest are considered to be of equal status. To any such event days are added or subtracted from the date of observation so as to yield the date when the clutch under consideration was completed.