лягушка пишет:
| цитата: |
JOrnitho
I think it is good idea.
We can call it simply "oryx's mesquite" or "acacia mesquite". Also, don't forget about existence of true "acacias" (Vachelia sp.) in America - they also may be sood ancestors.
|
|
I think that oryx's mesquite is a good name.
Also, I finished the description of the Rheomys for the chapter about the Panama Peninsula:
Lutrine mouse (Lutreomys amphibius)
Order: Rodentia
Family: Cricetidae
Habitat: Freshwater reservoirs of tropical lowland and cloud forests of the Panama Peninsula
The transition of the Holocene to the Neocene gave opportunities for species to evolve into new forms. The Goldman's water mouse (Rheomys raptor) was one of these species. It had survived the anthropogenic onslaught, leaving the lutrine mouse as its descendant. This small rodent is a fully aquatic mammal that inhabits the freshwater reservoirs of tropical lowland and cloud forests of the Panama Peninsula.
The lutrine mouse has a body length of 20 cm, with a thick and slightly flattened tail that has a length of 18 cm. They have interdigital webbing between their fingers, while their hind feet are larger. Their fur is dark chestnut brown dorsally, while ventrally it’s light buff. They also have absent pinnae covered by a tuft of white fur. They have strong masseter muscles and the incisive teeth are strong and sharp.
This rodent is a predominantly carnivorous species, feeding on a variety of aquatic animals including fish, crustaceans, shellfish, small birds, eggs, mammals, frogs, and reptiles. They swim actively after prey, using their strong masseter muscles to deliver powerful bites while they hold the food with their forepaws. They are active during both night and day.
They are solitary, with both male and female lutrine mice maintaining a territory and avoiding each other. Males will frequently visit various female territories, seeking receptive females.
There is no breeding, reproduction occurs during the entire year and much of the courtship takes place in the water. It either uses pre-existing burrows or digs its own. The nesting chamber is lined with moss, dry grass and leaves. Litters of four to eight or more young are born after a twenty-four-day gestation period. The young are tiny and helpless at birth. Their eyes open at fifteen to eighteen days and they are fully weaned at about seven weeks. Females can produce two or three litters a year. The juveniles disperse after weaning, setting up their own territories. They are sexually mature at six to eight months and their life expectancy is about three years.
I also finished the description for the oryx:
Humped oryx (Americoryx gibbosus)
Order: Artiodactyla
Family: Bovidae
Habitat: Deserts and xeric shrublands of North America, from Northern Chihuahua Desert to the Death Valley in the Mojave Desert.
The humans were the greatest agents of environmental change during the Holocene. Species were extirpated from their habitats, while others were introduced in new places. In the United States, humans had introduced the scimitar oryx (Oryx dammah) to the state of Texas. While this species was extinct in its ancestral territories in the Sahara and Sahel, it had reached numbers of 12,000 animals living in American lands.
With the disappearance of humans, these antelopes were able to run free through the deserts and semi-arids of their “adoptive” land. However, they weren’t alone. In the same regions that they were introduced, gemsbok (Oryx gazelle) and addax (Addax nasomaculatus) were also left there.
With the advent of the Ice Age, the semi-arid of North America became dryer, with only resilient animals being able to survive. The gemsbok died out, with it went the addax, which had a small population. The only survivor was the scimitar oryx, an animal capable of spending months without water. However, the other two Hippotraginae antelopes left genetic material as part of the scimitar antelope’s gene pool. It happened due to the facility that these species had to hybridize with each other and the capability of having fertile hybrids.
The long term result of this hybridization was the humped oryx, the last Hippotraginae antelope in the world. Inhabiting deserts and xeric shrublands of North America, this animal is well adapted for this environment. They have a metabolism that functions at the high temperatures prevalent in their habitats, needing less water for evaporation to help conduct heat away from the body, enabling them to go for long periods without water. Most of the moisture that it consumes comes from its food and dew that condenses on plants. It also produces highly concentrated urine to conserve water. These adaptations combined allow this bovid to spend 10 months to one year without drinking. Another adaptation for this lifestyle is a hump located at their shoulders. In a case of convergent evolution with the camels, this hump stores fat, which the animal can break down into energy to meet its needs when resources are scarce, also helping dissipate body heat.
They can tolerate high temperatures that would be lethal to most mammals, such as 57 °C that can reach in certain areas of their range in the Mojave Desert. They have a network of fine blood vessels that carries blood from the heart to the brain, passing close to the nasal passage, thus allowing the blood to cool by up to 5 °C before reaching the brain, which is one of the more heat-sensitive organs of the body.
Sharing these arid lands with Arsinohippus, deermaras and Rapidocervus, the rhumped oryx avoid competition with them by feeding in different sources of food such as tall branches of desert trees, tall cactuses, dry and bitter grasses, and by preferring to forage during the night and crepuscular hours. Even with their adaptations to high temperatures, these animals prefer to be active during these more fresh hours. During the hottest hours of the day, it digs shallow depressions in the soft ground under shrubs or trees for resting.
However, its resting is brief. The humped oryx is nomadic, always moving in search of food. They can detect rainfall and move towards it, meaning they have huge ranges. While moving, humped oryx’s herds are followed by Rapidocervus, deermaras and other desert animals that know that these animals can offer protection and most importantly, find where the rains are falling.
The humped oryx is a large antelope. The males have 219 and 291 cm in head-and-body length and stand approximately 200 to 230 cm at the shoulder. Females are smaller, with a head-and-body length of 200 to 220 cm and a shoulder height of 195 to 210 cm. With their height, these animals can reach food in places that other animals can’t. Its coat is white with a reddish-brown throat and black markings on the forehead and down the length of the nose. The coat reflects the sun's rays, while the black portions and the tip of the tongue provide protection against sunburn. The white coat helps to reflect the heat of the desert. Their legs are light gray, while the tail is pure white, with only a black tip. The horns are like that of the oryxes of the Holocene. In males, they are 95 cm long, thick with large bases. In females, the horns are 80 cm and are thinner. Both sexes use their horns to defend against predators, while the males use it in intraspecific disputes. They have thick skin in the lips and inside the mouth that allow them to eat cactuses and plants full of spikes. Their characteristic hump is located at their shoulder.
While they are usually grazers, humped oryxes will change to browsing when the number of food is low. In the end, they can eat any plant material. Foliage, grass, flowers, herbs, shrubs, succulent plants, legumes, juicy roots, buds, cactuses and desert fruits. Seeds are an important part of their diet. If necessary, they will dig after anything edible. They have a food retention time long in their stomachs and water retention, adaptations for life in deserts.
These animals live in herds of about 10–40 animals, which consist of a dominant male, a few nondominant males, and females. These herds are constantly moving, most of the time being followed by other desert herbivores. The humped oryx is polygynous, with the resident male mating with the receptive females in the herd. The male secures exclusive mating access to the females by attempting to herd mixed or nursery herds onto his territory. Breeding occurs throughout the year, but it peaks during winter and early spring. The young in a given herd tend to be of a similar age due to reproductive synchrony between females. Pregnant females leave the herd before giving birth. The gestation period lasts 270 days and mothers give birth to 1 calf. A postpartum estrus occurs after two or three days. The calf remains hidden 6 weeks after birth, after which mother and calf rejoin the herd. The calf is weaned at 3 months, becomes independent at 4 months, and achieves sexual maturity at 3 years in both sexes. Humped oryxes have a lifespan of 25 years.
- участник сейчас на форуме
- участник вне форума