From August 4 to 10, 1939, Chester C. Lamb collected birds at a locality three miles north of Tzitzio, eastern Michoacin, Mexico. From July 13 to 30, 1951, Mr. Lamb and his assistant, and my wife, Dr. Betty S. Davis, and I, made a second collection at this locality. We camped within a hundred yards of Mr. Lamb's 1939 campsite. The two collections total 310 specimens, all of which are now in the Moore Collection, Occidental College. Eighty-three species were recorded, of which seventy were collected. Eighteen miles by road east of Morelia, Michoacan, at a military outpost known as El Temescal, a road leaves the main highway to Mexico City and leads south to Huetamo, on the Michoacan-Guerrero boundary. The town of Tzitzio (Sitzio on some maps) is situated on this road, about ten miles by road south of the main highway to Mexico City. Our camp was located at the settlement of San Juan de los Llanos, on the Huetamo road, an estimated three miles airline north of Tzitzio. The altitude at San Juan was 6500 feet as registered on our altimeter. Many of the slopes and ridges in this area are covered with a second growth pine-oak forest, the pines being predominant. Much of this forest has been cleared away to make space for cultivated fields and grassy pastures. Isolated stands of pines and oaks scattered throughout the grassland indicate that the pine-oak forest was once continuous in this area. There has also been a heavy upward invasion of the leguminous thorn scrub vegetation of lower elevations. This scrub forms impenetrable thickets bordering roads and trails and breaking up the continuity of the grassland areas. Thickets of thorn scrub often occur in conjunction with small stands of oaks, leading to the formation of an association best referred to as oak-thorn scrub. The partial clearing of the original pine-oak forest, together with the invasion of thorn scrub from below, has led to an intermingling of vegetational associations in the vicinity of San Juan. The composition of the avifauna reflects this interdigitation of associations, and high and low altitude species of birds are found together in this region. Our collecting activities were carried out in the immediate vicinity of San Juan, and all the vegetational associations were investigated. Much time was spent on a steep, pineoak forested ridge running east and west about 300 yards south of camp. The ridge was an estimated three hundred feet high and ended in a steep escarpment at the western end, below which lay the road to Huetamo. In the following species accounts July records pertain to 1951 and August records to 1939. Coragyps atratus. Black Vulture. These vultures were seen nearly every day. They were only slightly less common than Turkey Vultures. Cathartes aura. Turkey Vulture. These were seen every day. On most occasions they appeared in greater numbers than the Black Vultures but on at least one occasion they were outnumbered by them.