striped plateau lizard
Sceloporus virgatus
General description 4
Sceloporus virgatus, the Striped Plateau Lizard, is found in highlands and mountainous areas of Southwestern North America, in Arizona, New Mexico, and Northern Mexico (Brennan 2008). This species is non-migratory (Hammerson et al 2007). It inhabits Madrean Evergreen Woodland, Petran Montane Conifer Forest, and Petran Subalpine Conifer Forest communities (Brennan 2008), 1,500-2,900 m elevational range. They are a 10-18 cm lizard with a reddish-brown color, sides have dark striped interspersed with light ones. Breeding females have two red-orange patches either side of the throat (Weiss et al 2009).
S. virgatus are diurnal and eat primarily grasshoppers and other insects, but will also eat centipedes (Brennan 2008). The species is generally terrestrial, but can climb well and will do so to avoid predators. They currently are not listed as threatened by IUCN and have no current pressing threats to existing populations (Hammerson et al 2007).
The size and chroma of the two orange spots which females of S. virgatus display on their throat during the breeding season is indicative a female breeding quality in terms of body size, mite load, and overall reproductive health. This making this species one of relatively few which shows sexual selection leading to female secondary sexual ornamentation, in which the males select females for mating based upon secondary sexual characteristics (Weiss et al 2009). Mating takes place in April and May, and results in a clutch of 5-15 eggs. Eggs are laid in June or July in an underground nest in moist soils. Hatching takes place in August (Brennan 2008). Within a clutch, occasional multiple paternity indicates that a female will mate with many males during each breeding season (Abell 1997).
An interesting aspect of the biology of these lizards is the sex-specific asymmetry which characterizes their cloacal microbiota. The presence of commensal, coevolved bacteria in the gut of vertebrates is crucial to the breakdown of many foods, and is likely a result of a complex coevolution between microbes and their vertebrate hosts. Cloacal sampling should be an appropriate indicator of symbiotic bacteria aiding in fermentation in the gut of birds and reptiles (Lucas 2005, White 2011, Stewart 2000). In S. virgatus, however, it was observed that surgically removed eggs had a lower hatching rate than those which were laid naturally, and from this observation it was postulated that some sort of interaction between the surface of eggs and the cloaca through which they pass in natural laying was influencing the observed difference in hatching rate (S.Weiss, unpublished observation). After subsequent investigation of the bacterial communities populating the cloaca of these lizards, the discovery was made that the cloacal microbiota of female striped plateau lizards is significantly less diverse than that of males of the species which may lead to them becoming an organism of greater focus in understanding how gut microbiota is managed, physiologically or otherwise, in vertebrates (Martin et al 2010).
Fuentes y créditos
- (c) matt knoth, algunos derechos reservados (CC BY-NC-ND), http://www.flickr.com/photos/18158503@N00/2598760479
- (c) Kenneth Bader, algunos derechos reservados (CC BY-NC), subido por Kenneth Bader
- (c) John Sullivan, algunos derechos reservados (CC BY-NC), subido por John Sullivan
- (c) Madison Cox, algunos derechos reservados (CC BY), http://eol.org/data_objects/27353620
