# Deer — Facts, Threats & Conservation

*Cervidae*

> Deer are antlered, hoofed ruminant mammals of the family Cervidae, comprising about 50 species worldwide; most are Least Concern, but several, including Père David's deer (Extinct in the Wild) and the hog deer, are threatened.

**IUCN status:** Varies by species (Least Concern to Extinct in the Wild)  ·  **WARN range:** Worldwide

## Quick facts
| Fact | Value |
| --- | --- |
| Lifespan | Commonly 6–14 years in the wild; up to about 20 years in captivity (varies by species) |
| Weight | From ~9 kg (Southern pudu) to over 600 kg (moose) |
| Size | Shoulder height roughly 35 cm (pudu) to 2 m (moose) |
| Diet | Herbivore; browses and grazes on leaves, shoots, grasses, fruit and bark |
| Gestation | About 200 days in white-tailed deer; roughly 6.5–9.5 months across species |
| Young | Usually 1–2 per birth (twins common in well-fed does) |
| Baby name | Fawn (or calf in larger species) |
| Group name | Herd |
| Top speed | Around 30 mph (≈48 km/h) in many species |
| CITES | Several species listed (e.g. Père David's deer and hog deer); most are not |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Cervidae
- **Subfamilies:** Cervinae and Capreolinae

## Conservation status
- **Status:** Varies by species (Least Concern to Extinct in the Wild)
- **Population:** No single figure; abundant species number in the millions, while Père David's deer survives only in managed and reintroduced herds
- **Trend:** Mixed — stable or increasing for many common species, declining for several threatened ones
- **Assessed:** 2016
- **CITES:** Listed for several species (e.g. Père David's deer, hog deer); most cervids are not CITES-listed
- Cervidae is a large family, so conservation status must be read at the species level rather than for the group as a whole.

## Key facts: Deer
- Deer form the family Cervidae, with roughly 50 living species found across the Americas, Europe, Asia and North Africa, plus introduced populations elsewhere.
- Antlers are the family's signature trait: grown by males of almost all species (and by female reindeer), shed every year, then regrown, unlike the permanent horns of cattle or antelope.
- The Chinese water deer is the notable exception, growing tusk-like canine teeth instead of antlers.
- Deer are ruminants with a four-chambered stomach, browsing and grazing on leaves, shoots, grasses, fruit and bark.
- Conservation status varies widely: many deer are Least Concern, but Père David's deer is Extinct in the Wild and species such as the hog deer are Endangered.
- Sizes span an enormous range, from the cat-sized pudu to the moose, the largest living deer.

## What makes a deer a deer?
All deer belong to the family Cervidae within the order of even-toed ungulates (Artiodactyla), the same broad group as cattle, antelope and giraffes. The trait that sets cervids apart is the antler: a fast-growing bony structure that develops on the heads of males in nearly all species, is covered in a living skin called velvet while it grows, and is then shed and regrown on an annual cycle. This contrasts with the permanent, unbranched horns of bovids. Female reindeer (caribou) are unusual in growing antlers too, while the Chinese water deer grows none at all and instead bears protruding canine tusks. Deer are ruminants, digesting fibrous plant matter in a four-chambered stomach, and most have long legs built for running and leaping to escape predators.

## Diversity and where deer live
With about 50 species, deer are remarkably varied. The family is usually divided into two main groups: the Old World deer (such as red deer, sika, fallow and the muntjacs) and the New World deer (such as white-tailed deer, mule deer, brocket deer and the tiny pudus), along with reindeer and moose. Naturally they occur across North and South America, Europe, Asia and parts of North Africa, occupying forests, grasslands, wetlands, mountains and tundra. Humans have introduced several species, including red deer and fallow deer, to regions such as Australia and New Zealand where deer are not native. This wide distribution and adaptability is one reason deer are among the most recognised wild mammals on Earth.

## Conservation: a family of contrasts
Because the deer family is so large, no single conservation label fits it. Many species are assessed by the IUCN as Least Concern and are widespread or even locally overabundant, with the white-tailed deer being a prime example. At the other end, Père David's deer is classified as Extinct in the Wild and survives only because captive herds, later reintroduced in China, prevented its total loss. The hog deer is listed as Endangered, and other cervids fall into Vulnerable or Near Threatened categories, while several remain Data Deficient. The main pressures are habitat loss, hunting and competition with livestock. Reading any claim about 'deer' therefore requires knowing which species is meant.

## Antlers vs. horns: how deer differ from horned animals
| Feature | Deer (antlers) | Cattle and antelope (horns) |
| --- | --- | --- |
| Structure | Solid bone | Bony core covered in keratin sheath |
| Branching | Often branched | Usually unbranched |
| Shed each year? | Yes, shed and regrown annually | No, permanent and grow for life |
| Who grows them | Males of almost all species (and female reindeer) | Often both sexes, depending on species |
| Animal family | Cervidae | Bovidae |

## What WARN does
This guide is educational reference content created by the World Animal Rescue Network to support our broader mission of wildlife awareness and habitat protection. Deer are a globally distributed group, and at our current launch stage WARN does not fund dedicated deer programmes in any country; our funded field work is concentrated in five priority nations (Pakistan, Indonesia, Malaysia, Brazil and Colombia). We share this page to answer common questions accurately and to connect readers with the conservation themes, especially habitat protection, that underpin the survival of deer and the wildlife that depends on the same landscapes.

Healthy forests, wetlands and grasslands are what keep deer and countless other animals alive. By supporting WARN's habitat protection work, you help safeguard the wild landscapes that wildlife depends on. Note that at our current launch stage WARN funds field projects in Pakistan, Indonesia, Malaysia, Brazil and Colombia rather than dedicated deer programmes.

## Frequently asked questions: Deer
### How many species of deer are there?
There are roughly 50 living species in the deer family, Cervidae. Exact counts vary between about 47 and 55 depending on the taxonomic source and ongoing genetic research, but around 50 is the figure most commonly cited.

### Do deer really shed their antlers every year?
Yes. In almost all deer species the males grow a fresh set of antlers each year, carry them through the breeding season, then shed them and grow a new set the following year. Female reindeer also grow antlers, while the Chinese water deer grows none.

### What is a baby deer called?
A baby deer is usually called a fawn, especially in smaller species such as white-tailed and red deer. In larger species like moose, elk and reindeer, the young are often called calves.

### What is a group of deer called?
A group of deer is most commonly called a herd. Other collective nouns used historically include a 'mob' or, for some species, a 'bevy' or 'drove'.

### What do deer eat?
Deer are herbivores and ruminants. They browse and graze on leaves, twigs, shoots, grasses, herbs, fruit, nuts and bark, digesting this fibrous material in a four-chambered stomach. The exact diet depends on the species and season.

### Are deer endangered?
It depends on the species. Many deer, such as the white-tailed deer, are assessed as Least Concern and are abundant. However, several are threatened: Père David's deer is Extinct in the Wild, the hog deer is Endangered, and others are Vulnerable or Near Threatened.

## Sources
- [Wikipedia: Deer](https://en.wikipedia.org/wiki/Deer)
- [IUCN Red List: White-tailed Deer (Odocoileus virginianus)](https://www.iucnredlist.org/species/42394/22162580)
- [Wikipedia: Père David's deer](https://en.wikipedia.org/wiki/P%C3%A8re_David%27s_deer)
- [Animal Diversity Web: Cervidae](https://animaldiversity.org/accounts/Cervidae/)
- [Wikipedia: List of cervids](https://en.wikipedia.org/wiki/List_of_cervids)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/deer