Black-tailed deer, Cedros Island Mule deer, Cedros Island Black-tailed deer
The Mule deer (Odocoileus hemionus) is one of the most iconic and beloved wildlife in the American West. It is so-named because of its large ears that look like a mule's ears.
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CrepuscularCrepuscular animals are those that are active primarily during twilight (that is, the periods of dawn and dusk). This is distinguished from diurnal...
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FolivoreIn zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less ...
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HerbivoreA herbivore is an animal anatomically and physiologically adapted to eating plant material, for example, foliage, for the main component of its die...
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GraminivoreIn zoology, a graminivore (not to be confused with a granivore) is an herbivorous animal that feeds primarily on grass. Graminivory is a form of g...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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CursorialA cursorial organism is one that is adapted specifically to run. An animal can be considered cursorial if it has the ability to run fast (e.g. chee...
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BrowsingBrowsing is a type of herbivory in which an herbivore (or, more narrowly defined, a folivore) feeds on leaves, soft shoots, or fruits of high-growi...
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ViviparousAmong animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
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GrazingGrazing is a method of feeding in which a herbivore feeds on plants such as grasses, or other multicellular organisms such as algae. In agriculture...
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PolygynyPolygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male.
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HerdingA herd is a social grouping of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with...
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MigratingAnimal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migrati...
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Altitudinal MigrantAltitudinal migration is a short-distance animal migration from lower altitudes to higher altitudes and back. Altitudinal migrants change their ele...
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starts withDuring summer, Mule deer are a tannish-brown color and in winter they are brownish-gray. There is a white patch on their rump and they have a small white tail tipped with black. The fawns have a spotted coat. The males have forked antlers, which are shed in mid-February. Their next set of antlers then starts to grow immediately. Antlers have a covering of velvety skin until they are fully formed, at which point the buck scrapes off this layer. Females do not have antlers.
Mule deer inhabit most of the western area of North America, from the Alaskan coastal islands, down to southern Baja Mexico. They also occur from the northern border of the state of Zacatecas in Mexico and northwards through the Great Plains to Canada, in the provinces of Saskatchewan, British Columbia, Alberta, and the south of Yukon Territory. Mule deer migrate from low-elevation winter ranges to high elevations summer ranges. Although not all individuals in populations migrate, some will travel long distances between summer and winter ranges. These animals inhabit forests, grasslands, shrubland, fields, desert, and semi-desert depending on the season, preferring arid, open regions and rocky hillsides.
Mule deer are a social species and typically stay in groups of multi-generational families of related females with their offspring. Bucks that are older than yearlings will often group together, otherwise, they remain solitary. In the late summer and autumn, mixed family groups join together to form larger groups for protection during the winter. The largest males, having the biggest antlers, are the dominant ones, and they breed most often during the season of mating. Mule deer are primarily active during the morning, evening, and moonlit nights. In the middle of the day, the mule deer will rest in a cool, secluded area. Males prefer to bed down on rocky ridges, while females and fawns prefer open areas. Seasonal movements involve migrations from the summer ranges in higher elevations to lower winter ranges and are associated with lowering temperatures, severe snowstorms, and deep snow, which reduce food supply and mobility.
Mule deer are herbivorous (folivorous, graminivorous) animals that eat a wide variety of vegetable matter, such as fresh green leaves, lower branches of trees, twigs, and various types of grass. They particularly like blackberry and raspberry vines, mistletoe, grapes, mushrooms, and ferns. They are able to eat so carefully that they can even eat the fruit of cacti.
Mule deer are polygynous, with courtship and mating occurring within the group. From November to February, bucks evenly matched in strength and size compete in battles for access to mate with females. Gestation lasts 6 to 7 months and one or two fawns are born in early summer. There are often twin births after the first pregnancy. Nursing fawns stay hidden during the day in the underbrush while their mothers are away. They begin to accompany their mothers within a few weeks. The weaning process begins when the fawns are around 5 weeks old and it is usually completed by the time they are 16 weeks old. They usually stay with their mothers for their first full year. Does are sexually mature at about 18 months old but young bucks are not permitted to mate until the age of 3 or 4 years.
Today the most serious threat to wild Mule deer is the prevalence of Chronic Wasting Disease (CWD). This has been diagnosed in deer in the United States Rocky Mountains region, as well as other mid-western states. Further threats include great numbers of predator populations (e.g. feral dogs), competition for grazing with livestock, habitat loss, and other actions by humans. Their habitat in many regions is being lost, and in others dramatically fragmented, due to the human population growth, development, and natural events. Road construction, urban expansion, catastrophic wildfires, and the spread of invasive plant species also have led to habitat loss.
The total number of the Mule deer population is unknown today, but according to the Gohunt resource, specific populations were estimated in these regions: Colorado - 408,000 deers; Nevada - 106,000 deers; Utah - 80,600 deers. Overall mule deer numbers are stable today and they are classified as least concern (LC) on the IUCN Red List.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...