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Holbrookia maculata ruthveni
Bleached Earless Lizard spotted in the White Sands National Monument, New Mexico. This white lizard is a subspecies of the common lesser earless lizard. The bleached earless lizard is only found in the White Sands area, while the common lesser earless can be found throughout the central and southwestern United States, including most of New Mexico.
The bleached earless lizard is only found in the White Sands area. Adaptations over the last several thousand years allow the bleached earless lizard to thrive in the white sands dunes, but not in other darker environments.
One of the most notable adaptation that sets the bleached earless lizard apart from other common earless lizard populations is its color. The gypsum dunefield is fairly young in geological terms, only about 7,000 years old. Yet the bleached earless lizard has evolved within this short time span to gain a white coloration necessary for survival in this new environment. Against an all-white background, dark lizards can be seen relatively easily by predators like roadrunners or hawks. As predators targeted darker individuals, lighter individuals survived to reproduce. Over many generations this natural selection resulted in the bleached earless lizard’s unique white coloration. Bleached earless lizards have two black spots on each side of their abdomens. The lizards are typically around four inches (10.16 cm) long and are believed to live an average of four to five years in the wild. Their bodies and tails are both fairly flat. The term “earless” refers to the lack of external ear openings on the lizards. Despite not having these external openings, the bleached earless lizard does have the ability to hear. The bleached earless lizards eat a wide variety of insects including ants, beetles, bees, wasps, and grasshoppers.This species is the most active from midspring through early fall. Though they live across the dunefield, these lizards are most often seen by guests at the Interdune Boardwalk area in the mornings. In the heat of the day and late at night, the bleached earless lizards bury themselves in the loose soil for protection and temperature regulation. These lizards use head bobbing, leg stretching, and body compression as displays when other lizards encroach on their territory or to attract mates during the mating season. The mating season for the bleached earless lizard is from May to July. During this season, the lizards gain slight coloration that signals whether they are receptive to advances or that they have already become gravid. Experiments have shown that males can identify the different colorations and will display to those females who would be most responsive to their attention. Females lay one or two clutches per year. The clutch can be anywhere from one to twelve eggs, but is usually between four to six eggs.
17 Comments
Thanks for the SOTW recognition, and all of the great comments, much appreciated... glad everyone enjoyed see it on Project Noah as much as we did in real life!
Incredible! Congratulations!
Superb shot - great info - thank you
Congratulations!!! Nice spotting!!
Nice! Congrats!
Congratulations SargonR and such an interesting read. Thank you.
Congratulations to you and the lizard -Well done !
awesome capture SargonR,great notes too,congrats on the welldeserved SOTW and thanks for sharing
Congratulations SargonR, your Bleached Earless Lizard has been voted Spotting of the Week! This fascinating example of adaptation by natural selection won you the vote.
"You could easily miss it! Our Spotting of the Week, a Bleached Earless Lizard (Holbrookia maculata ruthveni), is a remarkable example of rapid color adaptation to environment.
Learn more about the notable animals which inhabit the white gypsum dunes of White Sands National Monument in New Mexico, USA: https://buff.ly/2JdTsJF "
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Interesting information about the evolution of camouflage in the species. Thanks for sharing this brilliant find SargonR.
Excellent info! Thank you for sharing and congrats on the SOTW.
Interesting spotting!
Great info.
Your spotting has been nominated for the Spotting of the Week. The winner will be chosen by the Project Noah Rangers based on a combination of factors including: uniqueness of the shot, status of the organism (for example, rare or endangered), quality of the information provided in the habitat and description sections. There is a subjective element, of course; the spotting with the highest number of Ranger votes is chosen. Congratulations on being nominated!
If you made the spotting and took the photo, I still like it.
Thanks Jim Nelson, but in the spirit of "full disclosure" I must admit the summary for this spotting (and the Little Whip Tail) were both taken from the National Parks Service webpage for White Sands National Monument (listed in the reference).
Great summary and photo, Sargon. The gypsum sands of White Sands are like nowhere else, very unique.