Occurrence of Slaty and Dwarf Vireos in Jalisco, Mexico
Occurence of Slaty and Dwarf Vireos in Jalisco, Mexico.-In the course of field work in theSierra de Autlan, 12 miles south of Authm, southwestern Jalisco, Mexico, in April of 1959, one of my Mexican assistants, Nazario Chavez, had the good fortune to collect specimens of both the Slaty Vireo (Neockloe brevipennis) and the Dwarf Vireo (Vireo nanus). These represent considerable extensions of the known ranges of these species.
According to the Mexican Check-list (1957), Neochloe brevipennis was known previously from Oaxaca, Veracruz, and Guerrero [also occurs in Morelos, see p. 88 of this issue.-editorl Vireo nanus was previously known from Oaxaca, Guanajuato (5 mi. NE Irapuato) , and Michoacan.
Our camp, in the Sierra de Autlln, was at an estimated elevation of 8COO feet in humid pine-oak forest. The vegetation zone name used here follows Leopold (Ecol., 31, 1950:507-518), but the zone itself, in the Sierra de Autlbn, is not typical of Leopold’s pine-oak forest. The oaks at this locality were very tall (60 to 90 feet) and were festooned with mosses, liverworts, and other epiphytes. There was a dense understory of rank herbaceous plants. Both of these vireos were called in to the vicinity of the collector by use of a combination of “squeaking” and “pigmy owling,” using in the latter case the bell-like notes of Glaucidium gnoma, which is also present in this range.
Other species of interest, found in association with the two vireos at this locality, included the Chestnut-sided Shrike-vireo (Vireolanilcs melitophrys) , the Scaled Antpitta (GraUaria guatimalensis) , the Olivaceous Woodcreeper (Sittasomw griseicatilus) , the Aztec Thrush (Ridgwayiu pi&cola), and the Cazique Hummingbird (Lampornis amethyst&us), and a single Flammulated Owl (Otus /lammeohs) which was caught in a nylon “mist” net placed across a small, heavily wooded arroyo. This last specimen also represents an extension of the known range of this species.
Grateful acknowledgment is made to the Western Foundation of Vertebrate Zoology at Los Angeles, for financial aid to complete my field studies, and also for much moral support and encouragement. All specimens mentioned above are deposited in the collections of the Foundation. The specimen of the Slaty Vireo has been compared with the type of Neochloe brevipeennis browni at the Museum of Vertebrate Zoology and proves to be referable to the nominate race N. b. brevi- pennis.-W. J. SCHALDACH, JR., Colima, Mexico, September 22, 1959.