Camelus dromedarius Linnaeus, 1758

Common Name and Species Ranking

Camelus dromedarius, commonly called the dromedary, is the tallest of the three living camel species.

Shoulder Height

Adult males stand 1.8 to 2.4 m (5.9 to 7.9 ft) tall at the shoulder, while adult females stand 1.7 to 1.9 m (5 ft 7 in to 6 ft 3 in) tall.

Weight

Males typically weigh 400 to 690 kg (880 to 1,520 lb), and females weigh 300 to 540 kg (660 to 1,190 lb).

Distinctive Morphological Features

Its distinctive features include a long curved neck, narrow chest, single hump (Bactrian camels have two), thick double-layered eyelashes, and bushy eyebrows.

Sensory Capabilities

Dromedaries have sharp vision and a good sense of smell.

Male Dulaa Structure

Males have a nearly 18 cm (7.1 in) long soft palate called a dulaa in Arabic, which they inflate to form a dangling deep pink sac that often mistaken for a tongue.

Dulaa Function

This structure is used to attract females during the mating season.

Base Coat Coloration

The dromedary's coat is generally brown, but can range from black to nearly white.

Piebald Dromedary Records

Leese reported piebald dromedaries in Kordofan and Darfur, Sudan.

Piebald Coloration Genetics

Piebald coloration in some camels is thought to be caused by the KITW1 allele of the KIT gene, though at least one other mutation likely also causes white spotting.

Hair Distribution

The dromedary's hair is long and concentrated on the throat, shoulders, and hump.

Head Features

Its large eyes are protected by prominent supraorbital ridges, and its ears are small and rounded.

Hump Height

The dromedary's hump is at least 20 cm (7.9 in) high.

Leg and Foot Structure

It has long powerful legs, with two toes on each foot that form flat, leathery pads.

Locomotion Pattern

Like giraffes, dromedaries move both legs on the same side of their body at the same time.

Comparison to Bactrian Camels

Compared to the Bactrian camel, the dromedary has a lighter build, longer limbs, shorter hairs, a harder palate, and an insignificant or absent ethmoidal fissure.

Comparison to Lama Species

Unlike camelids in the genus Lama, the dromedary has a hump; it also has a longer tail, smaller ears, squarer feet, and greater shoulder height than Lama species, and has four teats instead of the two found in Lama species.

Historical Native Range

Historically, the dromedary's native range covered hot, arid regions of northern Africa, Ethiopia, the Near East, and western and central Asia.

Habitat Preference

It typically thrives in areas with a long dry season and a short wet season, and is sensitive to cold and humidity, though some breeds can survive in humid conditions.

Initial Domestication

The dromedary was first domesticated in the southern Arabian Peninsula around 4000–3000 BC.

Near East Widespread Presence

It became widespread in the Near East in the 9th or 10th century BC.

First Camel Introduction to Egypt

The Persian invasion of Egypt under Cambyses in 525 BC brought domesticated camels to the region, but these Persian camels were not well-suited for trade or travel across the Sahara, where desert journeys were previously made with horse-drawn chariots.

Subsequent Egypt Introduction

Dromedaries were later introduced to Egypt from south-western Asia (Arabia and Persia).

North African Spread Post-Islamic Conquest

Their popularity increased after the Islamic conquest of North Africa: while the conquest itself was done primarily on horseback, new trade links to the Middle East allowed mass importation of camels.

Trans-Saharan Trade Role

These camels were well-suited for long desert journeys and could carry large amounts of cargo, enabling substantial trans-Saharan trade for the first time.

Uses in Libya

In Libya, dromedaries were used for transport, and their milk and meat formed a core part of the local diet.

Global Introduction Regions

Dromedaries were also shipped from south-western Asia to Spain, Italy, Turkey, France, the Canary Islands, the Americas, and Australia.

European Introduction Dates

They were introduced to Spain in 1020 AD and to Sicily in 1059 AD.

Canary Islands Introduction

Camels were exported to the Canary Islands in 1405 during European colonization of the area, and still exist there today, especially in Lanzarote and southern Fuerteventura.

Failed or Small Introduction Attempts

Attempts to introduce dromedaries to the Caribbean, Colombia, Peru, Bolivia, and Brazil were made between the 17th and 19th centuries; some were imported to the western United States in the 1850s and some to Namibia in the early 1900s, but today they exist in small numbers or are absent from these areas.

First Australian Camel Introduction

In 1840, around six camels were shipped from Tenerife to Adelaide, Australia, but only one male named Harry survived the journey, arriving on 12 October that year.

First Australian Camel Expedition Use

Harry was owned by explorer John Ainsworth Horrocks; he was ill-tempered, but was included in an expedition the following year because he could carry heavy loads.

Later Australian Imports

The next major group of camels was imported into Australia in 1860, and between 1860 and 1907 10 to 12 thousand dromedaries were imported, used mainly for riding and transport.

21st Century Domesticated Range

In the early 21st century, domesticated dromedaries are found in semi-arid to arid regions of the Old World.

Activity Pattern

Dromedaries are diurnal, meaning they are active mainly during the day.

Daily Activity Schedule

Free-ranging herds feed and roam throughout the day, though they rest during the hottest midday hours, and spend most of the night resting.

Herd Structure

Dromedaries form cohesive groups of around 20 individuals, made up of several females led by a dominant male; females may also take turns leading.

Male Social Groupings

Some males form bachelor groups or roam alone.

Disaster Aggregation Behavior

During migrations caused by natural disasters, herds may gather to form associations of hundreds of camels.

Dominant Male Herd Defense

Herd males prevent their females from interacting with bachelor males by standing or walking between them, and sometimes drive the bachelors away.

Australian Feral Home Range

In Australia, feral dromedaries have short-term home ranges of 50 to 150 km2 (19 to 58 sq mi), while their annual home ranges can cover several thousand square kilometres.

Common Displays of Displeasure

Special common behaviors of the dromedary include snapping at other individuals without biting, and stamping feet to show displeasure.

General Aggression Level

They are generally non-aggressive, except for rutting males.

Home Range Memory

They appear to remember their home ranges; in particular, females remember the places where they first gave birth or suckled their offspring.

Mating Season Male Behavior

Males become aggressive during the mating season, and sometimes wrestle.

Androgen Influence on Behavior

A 1980 study found that androgen levels in males influence their behavior.

Rutting Season Male Traits

Between January and April, when androgen levels are high during rut, males become difficult to manage, extrude their inflatable palate from the mouth, vocalize, and splash urine over their backs.

Grooming Behaviors

Camels scratch parts of their bodies with their legs or lower incisors, and may also rub against tree bark and roll in sand.

Natural Predators

Free-ranging dromedaries are preyed on by large predators native to their ranges, including wolves, lions, and tigers.

Sexual Maturity Rate

Dromedaries have a slow growth rate and reach sexual maturity more slowly than sheep or goats.

Maturity Variation Factors

The age of sexual maturity and the reproductive period vary geographically and between individuals.

Maturity Age Range

Both sexes can reach maturity by three to five years of age, though successful breeding may take longer.

Breeding Season Sperm Production

Dromedaries are considered atypical seasonal breeders: they produce sperm throughout the entire year, though sperm production decreases during the nonbreeding season compared to the breeding season, per Zayed et al., 1995.

Egyptian Breeding Season Timing

In Egypt, the breeding season occurs during spring.

Mating Frequency and Peak

Mating happens once a year, and peaks in the rainy season.

Breeding Season Duration

The mating season lasts three to five months, but may last a full year for older animals.

Reproductive Season Male Scent Marking

During the reproductive season, males splash urine on their tails and lower bodies.

Male Courtship Palate Display

To attract females, they extrude their inflatable soft palate, a trait unique to the dromedary.

Male Courtship Saliva Display

As the male gurgles, large amounts of saliva become foam and cover his mouth.

Male Dominance Displays

Males compete for dominance over females by trying to stand taller than one another, making low noises, and performing a series of head movements including lowering, lifting, and bending their necks backward.

Male-Male Combat Behavior

Males attempt to defeat rivals by biting the opponent's legs and holding the opponent's head between their jaws.

Copulation Foreplay

Copulation begins with foreplay: the male smells the female's genitalia and often bites that area or the area around her hump.

Copulation Mounting

The male forces the female to sit, then grasps her with his forelegs.

Copulation Penetration

Camel handlers often help the male insert his penis into the female's vulva; the male dromedary's ability to complete penetration on his own is disputed, though feral populations in Australia reproduce naturally.

Copulation Duration and Ejaculation

Copulation lasts 7 to 35 minutes, averaging 11 to 15 minutes, and normally includes three to four ejaculations.

Semen Characteristics

The semen of a Bikaneri dromedary is white and viscous, with a pH of around 7.8.

Gestation and Birth

A single calf is born after a 15-month gestation period.

Newborn Calf Mobility

Calves can move freely by the end of their first day.

Maternal Care Duration

Nursing and maternal care continue for one to two years.

Milk Substitute Feeding Study

In one study testing whether young camels could survive on milk substitutes, two one-month-old male camels were separated from their mothers and fed commercial milk substitutes made for lambs, and grew to normal weights for male calves after 30 days.

Lactation Yield Factors

Lactation yield varies by species, breed, individual, region, diet, management conditions, and lactation stage; the largest amount of milk is produced during the early period of lactation.

Lactation Period Length

The lactation period can last between nine and eighteen months.

Ovulation Type

Dromedaries are induced ovulators.

Oestrus Triggers

Oestrus may be triggered by the camel's nutritional status and day length.

Follicle Regression

If mating does not occur, the follicle that grows during oestrus usually regresses within a few days.

Oestrous Cycle Length

In one study, 35 complete oestrous cycles were observed in five nonpregnant females over 15 months.

Oestrous Cycle Follicle Timeline

The cycles were about 28 days long; follicles matured in six days, maintained their size for 13 days, and returned to their original size in eight days.

Optimal Follicle Size for Ovulation

Another study found that ovulation is most reliably induced when the follicle reaches 0.9–1.9 cm (0.35–0.75 in) in size.

Pregnancy Detection

In another study, pregnancy in females could be detected as early as 40 to 45 days of gestation by the swelling of the left uterine horn, where 99.5% of all dromedary pregnancies are located.