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Mule Deer Vs. Black-tailed Deer (8 Differences)

Mule deer and black-tailed deer are two species native to North America. Black-tailed deer are a smaller subspecies to the mule deer, but their differences are more than just in size. Mule deer and black-tailed deer may look similar at a distance, but they have distinct features that set them apart from one another.

This article compares the mule deer vs. black-tailed deer and discusses 8 key differences between them so that you can easily identify them.


Mule Deer vs. Black-tailed Deer – 8 Key Differences

These two North American deer are similar in many ways, but they also have many characteristics that set them apart. Continue reading to learn more about mule deer vs. black-tailed deer.

1. Mule Deer Are Larger Than Black-tailed Deer

Mule Deer
Mule Deer in Washoe Valley, Nevada | image by Ken Lund via Flickr | CC BY-SA 2.0

One of the most noticeable differences between mule deer and black-tailed deer is their size. The mule deer is larger than the black-tailed deer.

Mule deer measure from 4 feet up to 7 feet in length from nose to tail. Adult bucks weigh anywhere from 120 to over 300 pounds but usually average around 200 pounds. Adult mule deer does typically weigh between 100 to 200 pounds and average 150 pounds.

Black-tailed bucks, on the other hand, weigh around 150 to 200 pounds and does weigh less than 130 pounds. They’re smaller in appearance compared to the mule deer and only measure just over 3 feet in length.

Mule deer tend to be more muscular than black-tailed deer and have a somewhat stockier body shape, with large neck and shoulder muscles. Their head is much larger than that of a black-tailed deer and has larger ears.

2. Color Differences

While their color may often appear to be similar, more often than not, black-tailed deer tend to be darker colored than mule deer. Mule deer are reddish or grayish-tan-brown colored, depending on their habitat and time of year.

Black-tailed deer are gray to dark gray in color. Some may appear to be almost black-colored if they live in heavily wooded areas with dark forests. Mule deer tend to be more in open areas with grass and brush.

3. Tail And Rump Differences

black-tailed deer

The rump of mule deer is lighter in color than the black-tailed deer. Both have black on their tails, but the black-tailed deer’s tail is noticeably darker, with more black than a mule deer’s.

Additionally, black-tailed deer have broader and wider tails than mule deer. Mule deer have a more fuzzy white appearance on the underside of their tail.

4. Mule Deer Have Larger Antlers Than Black-tailed Deer

Mule Deer
Mule Deer at the Malheur National Wildlife Refuge in Oregon | image by USFWS via Flickr | CC BY 2.0

Antler size in deer is determined by their age, habitat, and diet. Mule deer and black-tailed deer antlers vary in size depending on a number of factors.

A typical mule deer buck will have a main beam that is at least 50% longer than a black-tailed buck of the same age. Mule deer antlers are much broader in spread and have a wider base.

Mule deer often have more prongs and points than black-tailed deer. Black-tailed deer antlers tend to be shorter and narrower.

The larger size of mule deer antlers is thought to be an evolutionary adaptation to help bucks compete for mates. In areas where both species occur, mule deer bucks typically outnumber black-tail bucks by 2-to-1 or more.

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5. Dietary Differences

The diet of the two deer is different based on their habitat and range. Both forage and feed on vegetation.

Since mule deer are usually in desert areas, they eat more grasses, weeds, and shrubs. Black-tailed deer feed on lichens and moss, fruits, and forest shrubs and grasses.

Both deer eat a similar diet, but it is different depending on where they live and what food sources are available.

6. Ranges And Habitat: Mule Deer Have A Larger Range

The mule deer is most common in the western regions of the United States, as well as Canada. Their range extends into the Rocky Mountains and south into northern Mexico and Baja California.

Black-tailed deer are in a smaller range of the western US in states like California, Oregon, and Washington. They live in the Pacific coastal areas of North America that extend as far north as British Columbia.

Black-tailed deer tend to stay closer to sea level than mule deer. They prefer forested habitats such as thickly wooded areas and coastal rainforests.

Deer hunters note that mule deer are easier to hunt than reclusive black-tailed deer because of their habitat. Black-tailed deer are much harder to spot in their densely wooded habitat.

Mule deer, on the other hand, prefer open areas, making them easier to see when hunting. They aren’t as reclusive as the black-tailed deer.

7. Herding And Social Behavior Differences

Family of black tailed deer
Family of black-tailed deer | image by Allan Hack via Flickr | CC BY-SA 2.0

Mule deer and black-tailed deer have different social behaviors. Black-tailed deer generally do not stay in large groups and don’t usually herd together unless gathered in a feeding area.

Black-tailed deer might be observed in large groups foraging and feeding together, but they only remain in groups of 3 or 4 deer when moving around, and they’re usually family groups.

Mule deer are much more social animals and tend to stay in larger herds. They move in and out of larger herds during mating season and certain times of the year.

Mule deer mothers will often allow other does to help care for their fawns. Black-tailed deer mothers are more protective of their young and will chase away any does that come too close.

Overall, mule deer tend to stay in large herds of families. The young bucks leave once they reach sexual maturity.

Bucks in both species will compete for dominance through ritualized fighting during the rutting season. Mule deer tend to be more out in the open when sparring.

8. Lifespans

Black-tailed deer enjoy an average lifespan of up to 9 years in the wild. The oldest black-tailed doe recorded in the wild was around 20 years old. In captivity, they live even longer, on average between 17 and 20 years.

Mule deer lifespan in the wild is usually around 11 years. They can also live up to 20 years in captivity, like the black-tailed deer.