5 mi. N Tehuacan', 1676m. May 27 Airophila mystacalis - seen May 26; Phainopeble - not common on hillside ; Vermillion flycatcher -common around big trees ; Oxide sp? -common ; Kiskadee flycatcher - around big trees ; grosbeak - big trees; Centuries - common in cortes ; Dendrocosps scabros? - in big trees ; white-winged dove ; mourning dove ? Cotae ground dove - common, Turdos migratorius -big tree ; black-headed grosheat -big tree. Picture : Roll 28 - 1,2,3,4- Bonnie took these of wrens building nest in yucca line near the car . 5&6 - slope across the road showing typical desert vegetation where I found a group of wrens. 7 - trees where I shot group of 3 as they came to rest May 26 ; 8 -big tree habitat near marshy area . 9 - another shot of same area ; 10 - nest tree where I flushed 3 birds last evening, showing small mesquite in background where nest containing eggs was located. - The fact that joceros is not limited to scrubby desert vegetation convinces me that it may be possible to find a contact between this form and gularis since that from has a rather wide ecological range to judge from reports in literature and my observations of last year when we found it in ribaucan vegetation and frequently tall walnut trees in a desert area in Hidalgo.