=Pied-billed Grebe=: _Podilymbus podiceps podiceps_ (Linnaeus).--This is a common but local summer resident, in and on ponds, marshes, streams, ditches, and lakes. The species can be seen in the State at any time, but usually arrives in the period March 1 to April 13 (the median is March 21), and departs southward in the period October 13 to November 18 (the median is October 24). _Breeding schedule._--Nineteen records of breeding span the period May 1 to June 30; the modal date for egg-laying is May 15. _Number of eggs._--Clutch-size is 4 to 10 eggs. Nests are floating masses of marsh vegetation (cattail, smartweed, duckweed, filamentous green algae, and the like), kept green on top by addition of fresh material, in or at the edge of emergent marsh vegetation. =Double-crested Cormorant=: _Phalacrocorax auritus auritus_ (Lesson).--This is a transient, but has been found nesting on one occasion in Barton County (Tordoff, 1956:311). _Breeding schedule._--Eggs were laid in July and August in the one known nesting effort. _Number of eggs._--Clutch-size is 2 to 4 eggs (Davie, 1898). =Great Blue Heron=: _Ardea herodias_ Linnaeus.--This common summer resident nests in tall trees along rivers, streams, and marshes. The sector of greatest abundance is the Flint Hills. _A. h. herodias_ Linnaeus occurs in extreme northeastern Kansas, _A. h. wardi_ Ridgway breeds in southeastern Kansas, and _A. h. treganzai_ Court breeds in western Kansas; specimens showing intermediate morphology have been taken from the central part of the State. Occurrence in time, exclusive of the few that overwinter in Kansas, is shown in Table 10. _Breeding schedule._--Seventy-seven records of breeding span the period March 1 to April 30 (Fig. 3); the modal date of egg-laying is April 5. _Number of eggs._--Clutch-size is 4 eggs (4.4, 3-6; 36). Nests are placed in crotches of sycamore, cottonwood, elm, hackberry, oak, and walnut, from 30 to 60 feet high; the average height is about 40 feet. TABLE 10.--OCCURRENCE IN TIME OF SUMMER RESIDENT HERONS IN KANSAS