Ornate tree lizard
Urosaurus ornatus, commonly known as the ornate tree lizard, is a species of lizard in the family Phrynosomatidae. The species is native to the southwestern United States and northwestern Mexico. The species, which was formerly called simply the "tree lizard", has been used to study physiological changes during the fight-or-flight response as related to stress and aggressive competition. Its life history and costs of reproduction have been documented in field populations in New Mexico and Arizona. This species has been fairly well studied because of its interesting variation in throat color in males (within a population) that can correlate with different reproductive strategies,
Di
DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
Ca
CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
In
InsectivoresAn insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of e...
Ar
ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
Sc
ScansorialScansorial animals are those that are adapted to or specialized for climbing. Many animals climb not only in tress but also in other habitats, such...
Te
TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Te
TerritorialA territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
Po
PolygynyPolygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male.
Po
PolygamyPolygamy is the practice of breeding with multiple partners. When a male breeds with more than one female at the same time – it is called polygyny....
Do
Dominance hierarchyA dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social gr...
So
SocialHi
HibernatingHibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy charac...
No
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
U
starts withThe ornate tree lizard may grow to a snout-to-vent length (SVL) of up to 59 millimetres (2.3 in). As adults, all males have paired turquoise patches of skin on the abdomen; females lack this abdominal coloration. Male ornate tree lizards are found in a variety of colors. While not all populations contain more than one or two colors, 9 color types have been documented within U. ornatus. A population documented in Verde River, Arizona, has two types of coloration patterns among male tree lizards that account for 45% of all males. The first is characterized by a blue spot in the center of a larger orange patch on the throat fan ("dewlap"). The second has a solid orange throat fan ("dewlap"). The orange-blue males are more aggressive and defend territories that can include up to four females. The orange males have longer, leaner body types and are much less aggressive. Orange males can be nomadic during dry years, and during rainy years tend to occupy small territories.
The size of each lizard is closely related to their age and the seasonal state of their environment. During winter months (January through March), 75% of adults and 25% of juveniles are active and 13% of juveniles are active in the spring season. Additionally, at the beginning of April, 87% of the ornate tree lizards are in a reproductive state. This is because the beginning of April marks the beginning of their breeding season. By the month of May, however, all the lizards have reproductive potential.
Urosaurus ornatus is one of the most widespread and abundant of North American lizards. It inhabits a wide range of states throughout the United States, including California, Nevada, Utah, Colorado, Wyoming, Arizona, New Mexico, and Texas. It is arboreal, semi arboreal, or saxicolous throughout its wide living range and habitats. It can also be found in areas in Mexico including states such as Sonora, Sinaloa, Chihuahua, and Coahuila.
There are large temperature ranges throughout the southwestern United States and these lizards adapt to the different climates that they live in. Their mean body temperatures also change depending on where they are located. If the male lizard was in a montane habitat or a desert habitat their body temperature would be 35 degrees Celsius, but if the male lizard was in a desert riparian habitat its body temperature would be around 38 degrees Celsius. Their changes in body temperatures reflect the climates they live in. These temperature differences also occur between male and female lizards. On average the body temperature of a female is lower than the males body temperature. There is a possibility that this difference in body temperature could be related to the presence or absence of sexual differences between males and females and could also affect the health of the clutch and the size of the clutch.
These lizards tend to be active during every month except December. Both male and female ornate tree lizards emerge only on the warmest days in November and January, however, they engage in extended period of activity in February. When the lizards are active, they tend to occupy open locations in small or large boulders.
Male Usosaurus ornatus lizards express chemical and behavioral responses to predators. Chemical responses of the males when encountering a predator can include changes in their levels of testosterone and corticosterone while behavioral responses shown tend to be hiding and flight initiation distance (FID, the distance between the animal and the predator before escape is attempted). Levels of expression in both chemical and behavioral responses can differ depending on color variation of the throat. Chemical levels in both O and OB males can change significantly when predators are spotted. When encountered with a predator, the lizard's corticosterone levels in both O and OB males spike, but both types of males have the same hormone levels. When looking at testosterone levels in both O and OB males when encountering a predator, both males testosterone levels spiked, but the O males had higher testosterone levels than the OB males. When looking at behavioral responses there is also a difference in hiding time and flight distance. When encountering a predator O males have a larger flight distance compared to OB males, meaning that O males will escape when a predator is farther away when compared to an OB male, which will let the predator get closer before escaping. Hiding time differed between O males and OB males, where O males had significantly longer hiding periods after the encounter with the predator when compared to OB males. Overall OB males express lower chemical levels, shorter flight distances, and shorter hiding periods when encountered with a predator compared to O males.
The differences in anti-predator behavior can be attributed to the binding capacity of plasma binding globulins. Binding globulins regulate steroid hormone impacts on behavior and physiology in the body can cause differences in hormone levels which can affect changes in behavior. When bound to a corticosteroid-binding globulin (CBG), plasma corticosterone may not diffuse into target cells, and thus, sensitivity of individuals to circulating corticosterone can depend on binding capacity and level of CBG. The binding affinity of the androgen-glucocorticoid-binding globulin (AGBG) in tree lizards is similar between the territorial OB and nonterritorial O males, but AGBG has a greater binding capacity in OB males. Nonterritorial O males have higher levels of free corticosterone than do territorial OB males during stressful events due to the differences in binding capacity and levels of CBG. This free corticosterone difference could contribute to the higher behavioral reactivity - greater flight initiation distances and longer hiding duration - of O males compared to OB males in response to predation risk.
Territoriality is an important part of reproduction for many males in this species. Males often defend territories by aggressively excluding other males. This aggression can, in part, be enhanced with higher levels of the steroid hormones testosterone and progesterone. Females have home ranges but they do not defend territories. When the number of females on a male's territory is experimentally reduced by removing the females, the male is more likely to abandon his territory.
The ornate tree lizard feeds on mostly insects and their larvae, but have also been known to eat plants and vegetables as well as inanimate objects thinking they were food. These lizards also have diet patterns that change throughout the seasons changing what they eat and the quantity of it. In the winter/spring time their main food sources and largest quantity of food eaten were from the insect families Homoptera, Formicidae, Hemiptera, and Lepidopterous larvae but in the summer their diet changed to their main food sources mostly consisting of the insect families Coleoptera and Formicidae. For the ornate tree lizard, their food intake is variable. Multiple studies have provided evidence that the diet of the Urosaurus ornatus is seasonally variable—the diet changes according to changes in the seasons. Because they are abundant in areas where there are more trees, they depend on the food available in that niche. When the seasons undergo change or the prey migrate, it induces changes in the abundance of the lizards food and its availability.
A group of U. ornatus, consisting of one male and one or more females, typically inhabits an area containing one or more large trees, shrubs, or boulders. The male copulates with each female, and the females retain eggs about two weeks after mating. In many parts of its range, females may lay more than one clutch of eggs a year.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...