Chameleon - Change of Color

Some chameleon species are able to change their skin coloration. Different chameleon species are able to vary their colouration and pattern through combinations of pink, blue, red, orange, green, black, brown, light blue, yellow, turquoise, and purple.

Color change in chameleons has functions in social signaling and in reactions to temperature and other conditions, as well as in camouflage. The relative importance of these functions varies with the circumstances, as well as the species. Color change signals a chameleon's physiological condition and intentions to other chameleons. Chameleons tend to show darker colors when angered, or attempting to scare or intimidate others, while males show lighter, multicolored patterns when courting females.

Some species, such as Smith's dwarf chameleon, adjust their colors for camouflage in accordance with the vision of the specific predator species (bird or snake) by which they are being threatened.

The desert-dwelling Namaqua chameleon also uses color change as an aid to thermoregulation, becoming black in the cooler morning to absorb heat more efficiently, then a lighter grey color to reflect light during the heat of the day. It may show both colors at the same time, neatly separated left from right by the spine

Chameleon - Classification

The Chamaeleonidae family was divided into two subfamilies, Brookesiinae and Chamaeleoninae, by Klaver and Böhme in 1986. Under this classification, Brookesiinae included the genera Brookesia and Rhampholeon, as well as the genera later split off from them (Palleon and Rieppeleon), while Chamaeleoninae included the genera Bradypodion, Calumma, Chamaeleo, Furcifer and Trioceros, as well as the genera later split off from them (Archaius, Nadzikambia and Kinyongia). Since that time, however, the validity of this subfamily designation has been the subject of much debate, although most phylogenetic studies support the notion that the pygmy chameleons of the subfamily Brookesiinae are not a monophyletic group. While some authorities have previously preferred to use this subfamilial classification on the basis of the absence of evidence principle, these authorities later abandoned this subfamilial division, no longer recognizing any subfamilies with the family Chamaeleonidae. In 2015, however, Glaw reworked the subfamilial division by placing only the genera Brookesia and Palleon within the Brookesiinae subfamily, with all other genera being placed in Chamaeleoninae

Chameleon - Etymology

The English word chameleon is a simplified spelling of Latin chamaeleōn, a borrowing of the Greek χαμαιλέων (khamailéōn), a compound of χαμαί (khamaí) "on the ground" and λέων (léōn) "lion". The Greek word is a calque translating the Akkadian nēš qaqqari, literally "lion of the ground".

Chameleon

Chameleons or chamaeleons (family Chamaeleonidae) are a distinctive and highly specialized clade of old world lizards with 202 species described as of June 2015. These species come in a range of colours, and many species have the ability to change colours. Chameleons are distinguished by their zygodactylous feet; their very long, highly modified, rapidly extrudable tongues; their swaying gait; and crests or horns on their distinctively shaped heads. Most species, the larger ones in particular, also have a prehensile tail. Chameleons' eyes are independently mobile, but in aiming at a prey item, they focus forward in coordination, affording the animal stereoscopic vision. Chameleons are adapted for climbing and visual hunting. They are found in warm habitats that range from rain forest to desert conditions, various species occurring in Africa, Madagascar, southern Europe, and across southern Asia as far as Sri Lanka. They also have been introduced to Hawaii, California, and Florida, and often are kept as household pets.

Crotalus Atrox Reproduction

Rattlesnakes, including C. atrox, are viviparous. Gestation lasts six or seven months, and broods average about a dozen young. However, the young only stay with the mother for a few hours before they set off on their own to hunt and find cover, thus the mortality rate is very high. Mating occurs in the fall, and the females give birth to as many as 25 young, which may be as long as 30 cm (12 in). The young are fully capable of delivering a venomous bite from the moment they are born.

Crotalus Atrox Venom

Like most other American pit vipers, the venom contains proteolytic enzymes. Proteolytic venoms are concentrated secretions that destroy tissues as a result of catabolism of structural and other proteins, which help in disabling prey. The venom of C. atrox is primarily hemotoxic, affecting mainly the blood vessels, blood cells and the heart. The venom contains hemorrhagic components called zinc metalloproteinases. The venom also contains cytotoxins and myotoxins which destroy cells and muscles that add to the failure of the cardiovascular system. In addition to hemorrhage, venom metalloproteinases induce myonecrosis (skeletal muscle damage), which seems to be secondary to the ischemia that ensues in muscle tissue as a consequence of bleeding and reduced perfusion. Microvascular disruption by metalloproteinases also impairs skeletal muscle regeneration, being therefore responsible for fibrosis and permanent tissue loss after bites from this species. General local effects include pain, heavy internal bleeding, severe swelling, severe muscle damage, bruising, blistering, and necrosis; systemic effects are variable and not specific, but may include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, and convulsions. Hemorrhagins causing bleeding is a major clinical effect. This species has LD50 values of 2.72 mg/kg intravenous, 20 mg/kg intramuscular and 18.5 mg/kg subcutaneous, which is far less toxic than many other rattlesnakes. However, because of its large venom glands and specialized fangs, the western diamondback rattlesnake can deliver a significant amount of venom in a single bite. The average venom yield per bite is usually between 250 and 350 mg, with a maximum of 700–800 mg. Severe envenomation is rare, but possible, and can be lethal. Mortality rate of untreated bites is between 10 and 20%.

Crotalus Atrox Prey

A comprehensive study by Beavers (1976) on the prey of C. atrox in Texas showed, by weight, 94.8% of their prey consisted of small mammals. According to Pisani and Stephenson (1991), who conducted a study of the stomach contents of C. atrox in the fall and spring of Oklahoma, mammalian prey included prairie dogs (Cynomys ludovicianus), kangaroo rats (Dipodomys ordii), pocket gophers (Geomys bursarius and Cratogeomys castanops), voles (Microtus ochrogaster), woodrats (Neotoma floridana), pocket mice (Perognathus hispidus and P. flavescens), white-footed mice (Peromyscus leucopus and P. maniculatus), Old World rats and mice (Rattus norvegicus and Mus ssp.), harvest mice (Reithrodontomys megalotis), fox squirrels (Sciurus niger), cotton rats (Sigmodon hispidus), ground squirrels (Spermophilus spilosoma), rabbits (Sylvilagus floridanus), jackrabbits (Lepus californicus), and an unidentified mole species. Klauber (1972) mentioned large specimens are capable of swallowing adult cottontail rabbits and even adult jackrabbits, although he figured the latter required confirmation. Birds, lizards, and mice are also preyed upon, with lizards mostly being eaten by young snakes. Avian prey include mockingbirds (Mimidae), quail, a nearly full-grown Gambel's quail, a burrowing owl (Athene cunicularia), a fledgling horned lark (Eremophila alpestris) a black-throated sparrow (Amphispiza bilineata), and an eastern meadowlark (Sturnella magna). Lizard prey include a whiptail lizard (Cnemidophorus), spiny lizards (Sceloporus), a Texas banded gecko (Coleonyx brevis), and a side-blotched lizard (Uta palmeri). One case reported by Vorhies (1948) involved a juvenile specimen that had attempted to eat a horned lizard (Phrynosoma solare), but died after the lizard's horns had punctured its esophagus, leaving the lizard stuck there. Hermann (1950) reported C. atrox also feeds on lubber grasshoppers (Brachystola magna). Klauber (1972) once found a single specimen in which the stomach contents included grasshoppers, beetles, and ants. However, mammal hairs and an iguanid lizard were also found in the same stomach, which made it more likely that the insects had first been eaten by the mammal or the lizard before they had been eaten by the snake. They hunt (or ambush prey) at night or in the early morning. These snakes can go for up to two years without food in the wild. A 5½-month starvation study showed the snakes reduced energy expenditures by an average of 80% over the length of the study. The snakes also feed from within on energy-rich lipid stores. The most interesting finding was the snakes grew during the study, indicating while the snake's mass was shrinking, it was putting its resources into skeletal muscles and bone. A key participant in the food chain, it is an important predator of many small rodents, rabbits, and birds. In turn, it is preyed upon by a variety of larger mammals and birds, such as coyotes, foxes, hawks, and owls. Crotalus atrox can be active at any time of the day or night when conditions are favorable. It is primarily diurnal and crepuscular in spring and fall and becomes primarily nocturnal and crepuscular during the hot summer months.

Crotalus Atrox Behavior

Crotalus Atrox are solitary except during the mating season. Usually inactive between late October and early March, occasionally these ectotherms may be seen basking in the sun on warm winter days. In the winter, they hibernate or brumate in caves or burrows, sometimes with many other species of snakes. Life expectancy is more than 20 years.[citation needed] They are poor climbers. Natural predators include raptors such as hawks, eagles, roadrunners, and other snakes. When threatened, they usually coil and rattle to warn aggressors. They are one of the mor

Crotalus Atrox Habitat

Its habitats range from flat coastal plains to steep rocky canyons and hillsides; it is associated with many different vegetation types, including desert, sandy creosote areas, mesquite grassland, desert scrub, and pine-oak forests. Towards the southern

Crotalus Atrox Geographic range

It is found in the United States from central Arkansas to southeastern and Central California, south into Mexico as far as northern Sinaloa, Hidalgo and northern Veracruz. Disjunct populations exist in southern Veracruz and southeastern Oaxaca. The type locality given is "Indianola" (Indianola, Calhoun County, Texas, USA). In the United States, it occurs in central and western Arkansas, Oklahoma excluding the northeast, north-central region and the panhandle, Texas excluding the northern panhandle and the east, southern and central New Mexico and Arizona, extreme southern Nevada, southwestern Idaho, and in southeastern California on either side of the Chocolate Mountains. Records from extreme southern Kansas (Cowley and Sumner Counties) may be based on a natural occurrence of the species, while multiple records from near Kanopolis Reservoir in Ellsworth County seem to indicate a viable (although isolated) population. In Mexico, it occurs in Nuevo León, Coahuila, Chihuahua, Sonora, extreme northeastern Baja California, northern Sinaloa, northeastern Durango, Zacatecas, most of San Luis Potosí, northern Veracruz, Hidalgo, and Querétaro. Specimens have been collected in the mountains northwest of Tehuantepec, Oaxaca, on numerous occasions, but have not been reported there since the 1940s. This species has also been reported on a number of islands in the Gulf of California, including San Pedro Mártir, Santa María (Sinaloa), Tíburon and the Turner Islands.

Crotalus Atrox Common Names

Crotalus Atrox Snake

Crotalus atrox, the western diamondback rattlesnake, is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second-greatest number in the USA after C. adamanteus. No subspecies is currently recognized.

Crotalus Atrox

Crotalus atrox, the western diamondback rattlesnake, is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second-greatest number in the USA after C. adamanteus. No subspecies is currently recognized

Adults commonly grow to 120 cm (4 ft) in length. Specimens over 150 cm (5 ft) are infrequently encountered, while those over 180 cm (6 ft) are very rare. The maximum reported length considered to be reliable is 213 cm (7 ft). Males become much larger than females, although this difference in size does not occur until after they have reached sexual maturity. Rattlesnakes of this species considered medium-sized weighed 1.8 to 2.7 kg (4 to 6 lb), while very large specimens can reportedly weigh up to 6.7 kg (15 lb)

The color pattern generally consists of a dusty-looking gray-brown ground color, but it may also be pinkish-brown, brick red, yellowish, pinkish, or chalky white. This ground color is overlaid dorsally with a series of 24-25 dorsal body blotches that are dark gray-brown to brown in color. The first of these may be a pair of short stripes that extend backwards to eventually merge. Some of the first few blotches may be somewhat rectangular, but then become more hexagonal and eventually take on a distinctive diamond shape. The tail has two to eight (usually four to six) black bands separated by ash white or pale gray interspaces; this led to the nickname of "coon tail", though other species (e.g., Mojave rattlesnake) have similarly banded tails. Its postocular stripe is smoky gray or dark gray-brown and extends diagonally from the lower edge of the eye across the side of the head. This stripe is usually bordered below by a white stripe running from the upper preocular scale down to the supralabial scales just below and behind the eye. Its off-white belly is usually unmarked, its anal scale is undivided, and its dorsal scales are extremely keeled, often in rows of 25 to 27 near the midbody.

The wide range of this species overlaps, or is close to, that of many others. It may be confused with them, but differences exist. The Mohave rattlesnake, C. scutulatus, also has tail rings, but the black rings are narrow relative to the pale ones. The timber rattlesnake, C. horridus, has no tail rings. In the western rattlesnake, C. oreganus, the pale tail rings are the same color as the ground. The tail of the black-tailed rattlesnake, C. molossus, is a uniform black, or has indistinct tail rings. The Mexican west coast rattlesnake, C. basiliscus, also has a mostly dark tail with obscure or absent rings. The tiger rattlesnake, C. tigris, has a relatively small head and large rattle along with a dorsal pattern consisting more of crossbands. The Middle American rattlesnake, C. simus, has a generally uniform gray tail without any rings, as well as a pair of distinctive paravertebral stripes running down the neck. Members of the genus Sistrurus lack tail rings and have enlarged head plates.

Common names for this species include: western diamondback rattlesnake, western diamond-backed rattlesnake, adobe snake, Arizona diamond rattlesnake, coon tail, desert diamond-back, desert diamond rattlesnake, fierce rattlesnake, spitting rattlesnake, Texan rattlesnake, and Texas diamond-back, and Texas Rattler

Its habitats range from flat coastal plains to steep rocky canyons and hillsides; it is associated with many different vegetation types, including desert, sandy creosote areas, mesquite grassland, desert scrub, and pine-oak forests. Towards the southern

Black King Snake

The Mexican black kingsnake (Lampropeltis getula nigrita) is part of the larger colubrid family of snakes, and a subspecies of the common kingsnake, which is debated by herpetologists to contain as many as 10 unique varieties. This species occupy rocky areas and places lush with vegetation in various regions of the Sonora Desert, Northwestern Sinaloa, Mexico, and small parts of Arizona. In captivity, they can remain in excellent health through a strict diet of mice and generally require a temperature gradient between 70 and 85 degrees Fahrenheit.