Specimens examined.—(13) MÉXICO, Nayarit: 4.8 km. NW Tepic, 840 m., UMMZ 115451 (holotype). Sinaloa: Santa Lucía, 1090 m., KU 75263-72; 1 km. NE Santa Lucía, 1156 m., KU 78257; 2.2 km. NE Santa Lucía, 1156 m., KU 78258.
Discussion
There are relatively few clear-cut morphological differences among the fourteen species now assigned to Syrrhophus. The majority of the species are allopatric and differ primarily in color patterns. Sympatric occurrence serves as an indicator of specific distinctness and is one of the more practical tests of species validity when cross-breeding experiments are not possible. Two cases of sympatric occurrence are known for the species of Syrrhophus in western México: modestus and nivocolimae are sympatric in southern Jalisco and pipilans nebulosus and rubrimaculatus are sympatric in southeastern Chiapas. In eastern México, longipes and verrucipes are sympatric in southern Hidalgo, and longipes is sympatric with cystignathoides, dennisi, and guttilatus in southern Tamaulipas. Syrrhophus cystignathoides and leprus are apparently sympatric in central Veracruz.
Subspecific assignments have been made only when there is evidence of intergradation. The sympatric occurrence of morphologically similar species in this genus has led me to adopt a conservative approach to the degree of difference philosophy. I have therefore recognized all morphologically distinct allopatric populations as species.
Fig. 21: Generic distributions of Syrrhophus (stipple) and Tomodactylus (hatching). Black areas are zones of intergeneric sympatry.
