Western Hooknose Snake
Gyalopion canum
Summary 7
Gyalopion canum, commonly known as the Western hooknose snake, is a species of small colubrid snake endemic to the United States and Mexico. It is sometimes referred to as the Chihuahuan hook-nosed snake because it is commonly found in the Chihuahuan Desert.
Taxon biology 8
G. canum are small, stout snakes with average adult lengths of about 7-11 in (18-28 cm), with a record length of 15 inches (38.4 cm) observed (Degenhardt et al. 1996). They have an upturned rostral scale (snout) that comes to a point in the air, and lies flat or concave and wide on the head. G. canum may present a tan, yellow-brown or gray ground color, with a white, pale or slight salmon hued underside. The body contains a minimum of 25(30) dark brown or black horizontal jagged splotches that may become increasingly more pronounced on the head; 8- 12 on tail. This brown mask crosses the top of the head and covers the eyes on most specimens (Brennan 2006). They have round pupils and smooth dorsal scales; mid-body scale rows usually total 17. There are seven upper and seven lower labials, and the rostral scute splits the internasals but reaches back only as far as the prefrontal scales. Their anal plate is divided, although Degenhardt et al. (1996) reports that it may be single or divided. (Behler and King 1979; Degenhardt et al. 1996; Stebbins 2003; Brennan 2006; Brennan and Holycross 2006; BISON-M 2007).
They can be found from western Texas, throughout much of central and southern New Mexico, into the southeast portion of Arizona, south to northeast Sonora, Nayarit, Zacatecas, San Luis Potosí, and Michoacán, Mexico.
Typically nocturnal or crepuscular, G. canum prefers to spend the majority of its time underground in burrows or within rocks at the base of canyons or in grassy foothills. Their blunt rostrum suggests that they are skilled burrowers and the semi-fossorial character of these snakes makes sighting difficult. Surface rock and loose soils for burrowing are used for cover. Most surface encounters occur after rain or during mild or cloudy days. Although not well studied, G. canum’s active periods probably occur from April into the mid-fall when they undergo hibernation during winter. The somewhat unique anti-predator behavior these snakes display may include cloacal popping and closed mouth striking, though they have not been known to actually bite. They are also likely to whip their tails around when touched and smear musk on a pursuer. (Brennan 2006; Degenhardt et al. 1996; NatureServe 2006).
The preferred diet of G. canum is spiders, scorpions, centipedes and other arthropods; however, they may also feed on small snakes and lizards, and reptile eggs. (Degenhardt et al. 1996; Brennan & Holycross 2006).
Fuentes y créditos
- (c) A. Jaszlics, algunos derechos reservados (CC BY-NC), http://www.flickr.com/photos/8786969@N02/4974510439
- (c) 2011 Todd Pierson, algunos derechos reservados (CC BY-NC), http://calphotos.berkeley.edu/cgi/img_query?seq_num=390186&one=T
- (c) Diana-Terry Hibbitts, algunos derechos reservados (CC BY-NC), subido por Diana-Terry Hibbitts
- (c) Travis Dimler, algunos derechos reservados (CC BY-NC), subido por Travis Dimler
- (c) Chris McMartin, algunos derechos reservados (CC BY-NC), subido por Chris McMartin
- (c) Mallory L. Fontenot, algunos derechos reservados (CC BY-NC), subido por Mallory L. Fontenot
- (c) Wikipedia, algunos derechos reservados (CC BY-SA), http://en.wikipedia.org/wiki/Gyalopion_canum
- (c) Desconocido, algunos derechos reservados (CC BY-SA), http://eol.org/data_objects/17572811
