Stenocercus festae (Peracca)

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 115-117

Stenocercus festae (Peracca)

( Fig. 14 )

Liocephalus festae Peracca, 1897:6 . Neotype: QCAZ 4059 , an adult male from ‘‘ Sevilla de Oro (02 ° 48'S, 78 ° 39'W), 2630 m, Provincia Azuay, Ecuador ̕̕ designated by Torres-Carvajal (2000).

Leiocephalus ornatus ornatus Burt and Burt (part), 1931:271.

Ophryoessoides festae Etheridge, 1966:88 ; Peters, 1967:28; Etheridge, in Peters and Donoso-Barros, 1970:213.

Stenocercus festae Fritts, 1974:49 ; Torres-Carvajal, 2000:15.

Diagnosis.— Stenocercus festae differs from all other species of Stenocercus except S. angel , S. chota , S. guentheri , and S. nigromaculatus by having imbricate scales on posterior surface of thighs, smooth ventrals, a posthumeral mite pocket consisting of a shallow depression with a wide opening (more distinct in adult specimens), small scales on occipitoparietal region, and supraoculars of similar size. Of these species, S. nigromaculatus is unique in having an antehumeral fold. S. festae differs from S. angel and S. chota in adult males having a distinct, black transverse band on ventral surface of neck (polymorphic). In general, S. festae has larger scales than S. guentheri , which is reflected in relatively lower numbers for most scales counts ( Table 2 ). Juveniles of S. festae have distinctly keeled ventrals, which are smooth or weakly keeled in juveniles of S. guentheri . In addition, S. festae differs from S. guentheri in that adult males have a black antehumeral patch, although not always distinct, as well as in having higher frequencies of a dark patch on the ventral surface of the neck (93%), and a dark longitudinal midventral mark (93%; 50% and 66% in S. guentheri , respectively).

Description.—(1) Maximum SVL in males 102 mm (n = 36); (2) maximum SVL in females 79 mm (n = 44); (3) vertebrals 39–55; (4) paravertebrals 46–81; (5) scales around midbody 47–66; (6) supraoculars 4–6; (7) internasals 2–4; (8) postrostrals 3–6; (9) loreals 2–4; (10) gulars 16–29; (11) subdigitals on Finger IV 14–22; (12) subdigitals on Toe IV 21–33; (13) posthumeral mite pocket present as a shallow depression with a wide opening; (14) postfemoral mite pocket distinct with slit-like opening; (15) parietal eye visible through interparietal cornea in 79% of specimens; (16) scales on occipitoparietal region small, keeled or multicarinate, juxtaposed or subimbricate; (17) projecting angulate temporals absent; (18) row of enlarged supraoculars occupying most of supraocular region absent; (19) scales on frontonasal region weakly imbricate anteriorly; (20) preauricular fringe present; (21) neck folds absent; (22) lateral and dorsal nuchals similar in size; (23) posterior gulars rhomboidal, smooth or slightly keeled, imbricate, not notched; (24) lateral and dorsal body scales similar in size; (25) vertebrals larger than adjacent paravertebrals; (26) dorsolateral crest absent; (27) ventrals in adult specimens smooth, imbricate; (28) scales on posterior surfaces of thighs keeled, imbricate; (29) inguinal granular pocket absent; (30) inguinal groove absent; (31) preanals not projected; (32) tail not strongly compressed laterally in adult males; (33) tail length 61–69% of total length; (34) caudal whorls per autotomic segment three; (35) caudals not spinose; (36) dark brown stripe extending anterodorsally from subocular region to supraciliaries absent; (37) dark patch extensively covering gular region of females absent; (38) dark patch extensively covering gular region in 7% of adult males; (39) black patch on ventral surface of neck in 93% of adult males; (40) dark midventral longitudinal mark such as faint line, conspicuous stripe, or extensive patch in 93% of adult males; (41) dark patches on ventral surface of thighs in adult males absent; (42) postxiphisternal inscriptional ribs not in contact midventrally, Pattern 2B.

Color in life.—Dorsum grayish tan, grayish brown, pale olive brown, or brown, with or without short, transverse bands arranged longitudinally over vertebral line; flanks with or without scattered green or yellow flecks and blotches in adult males; females and juveniles with or without a pale gray, beige, or cream dorsolateral stripe; antehumeral region with large black mark in some males; supralabials and infralabials black in some males; gular region yellow, yellowish green, or orange in adult males and yellow or pale gray in females and juveniles; black patch on ventral surface of neck in most adult males; in some males venter entirely black, or yellowish-green to pale yellow with a black midventral stripe; venter pinkish white, pale yellow, or pale gray in females and juveniles, sometimes with scattered dark flecks; ventral aspect of pelvic region, base of tail, and thighs yellow in some males ( Torres-Carvajal, 2000).

Natural History.—This species is usually found at or near the base of Agave plants and small shrubs.

Distribution.— Stenocercus festae occurs in the northern Andes and inhabits the upper valleys of Río Paute (Atlantic drainage) and Río Jubones (Pacific drainage) in southern Ecuador (4 ° S–2 ° 20'S). This species is known from elevations between 1050–3200 m in Provincias Azuay, Cañar, El Oro, Loja, and Zamora-Chinchipe ( Fig. 17 ). S. festae is sympatric with S. simonsii in the upper valley of Río Jubones ( Fritts, 1974), and S. limitaris in Salvias, Provincia El Oro. Additionally, S. festae possibly occurs in sympatry with S. rhodomelas in the Saraguro Basin ( Torres-Carvajal, 2000).

Figures

FIG. 14.—Eight species of Stenocercus. (A) S. chota (LAC); (B) S. chrŋsopŋgus (MLU); (C) S. crassicaudatus (WED); (D) S. cupreus (MLU); (E) S. doellojuradoi (JAS); (F) S. dumerilii (TAP); (G) S. empetrus (RON); (H) S. festae (OTC).

FIG. 17.—Distribution of four species of Stenocercus in Ecuador and Peru.