The Enduring Equine: A Comprehensive Exploration of Donkeys (Equus asinus) 🐴
Introduction: More Than Just Beasts of Burden
The donkey (Equus asinus), often overshadowed by its equine cousin the horse, possesses a unique blend of resilience, intelligence, and quiet dignity that has cemented its partnership with humans for millennia. Far from being mere "stubborn" beasts of burden, donkeys are remarkably adapted animals with fascinating biology, diverse breeds, and significant ecological and economic roles worldwide. This in-depth article delves into the world of donkeys, exploring their origins, intricate biology, diverse types, dietary needs, global habitats, complex reproductive strategies, and their profound importance to human societies, all underpinned by global research and scientific understanding. 🌍
I. Evolutionary Origins and Domestication: A Journey from Africa
The story of the modern donkey begins in the harsh landscapes of northeastern Africa.
Wild Ancestors: The African Wild Ass (Equus africanus) is the sole progenitor of the domestic donkey. Two recognized subspecies exist:
Nubian Wild Ass (E. africanus africanus): Historically ranged in Sudan, Eritrea, and Ethiopia. Critically Endangered (CR) with tiny, fragmented populations. (IUCN Red List)
Somali Wild Ass (E. africanus somaliensis): Found in the Horn of Africa (Eritrea, Ethiopia, Somalia). Also Critically Endangered (CR), with perhaps fewer than 200 mature individuals remaining. (Moehlman et al., 2008 - Equids: Zebras, Asses, and Horses. Status Survey and Conservation Action Plan)
Domestication Timeline: Archaeological and genetic evidence points to domestication occurring in Egypt or the Near East around 5000-6000 BCE, possibly earlier than the horse. (Beja-Pereira et al., 2004 - Science). This process was driven by the need for reliable pack animals capable of thriving in arid environments where horses struggled.
Spread: Domesticated donkeys spread rapidly across the ancient world, reaching Mesopotamia, Asia Minor, Europe, and eventually the Americas via European colonizers. Their adaptability was key to their global dispersal.
II. Understanding Donkey Biology: Built for Toughness 🏜️
Donkeys exhibit distinct physiological and behavioral adaptations honed for survival in resource-scarce environments:
Physiology:
Thermoregulation: Highly efficient at conserving water and tolerating heat. They sweat less profusely than horses but more effectively, have a lower metabolic rate, and can reabsorb more water from their large intestine. (Smith & Pearson, 2005 - Equine Veterinary Journal).
Digestion: Possess a highly efficient digestive system, extracting maximum nutrients from coarse, fibrous, low-quality forage. Their large cecum acts as a fermentation vat.
Hooves: Smaller, tougher, and more upright than horse hooves, well-suited for rocky, uneven terrain but potentially more prone to certain pathologies if kept on soft, wet ground. (The Donkey Sanctuary - Hoof Care Guidelines).
Coat & Ears: Typically a short, coarse coat in shades of gray, brown, black, or roan. Large ears enhance hearing and act as radiators for heat dissipation.
Behavior and Intelligence:
"Stubbornness" Debunked: Often misinterpreted as stubbornness, donkey behavior is better understood as a strong instinct for self-preservation and a thoughtful, cautious approach to perceived danger. They assess situations carefully before acting. (Proops et al., 2009 - Animal Behaviour).
Social Structure: Naturally form strong, long-lasting pair bonds and stable social groups in free-ranging conditions. They are highly social animals. (McDonnell, 2003 - The Domestic Donkey).
Intelligence & Memory: Possess excellent long-term memory and problem-solving abilities. They learn quickly and respond well to patient, consistent, positive training methods. (Matsuzawa, 2010 - The Cognitive Abilities of Animals).
III. The Diverse Tapestry: Types and Breeds of Donkeys 🐎
Donkeys are categorized primarily by size, though distinct breeds exist globally. The Food and Agriculture Organization (FAO) recognizes over 180 distinct donkey breeds or populations.
Miniature Donkeys: Height < 36 inches (91 cm) at the withers. Originating primarily from the Mediterranean islands of Sicily and Sardinia. Prized as companions and pets (e.g., American Miniature Mediterranean Donkey). 🐾
Standard Donkeys: Height between 36.01 inches (91.5 cm) and 48 inches (122 cm) at the withers. This is the most common size globally, encompassing numerous breeds. Examples include the widespread "Common Donkey" and the French Baudet du Poitou (though Poitous are often larger). 🐴
Large Standard Donkeys: Height between 48.01 inches (122 cm) and 54 inches (137 cm) for females and 56 inches (142 cm) for males (jacks). Breeds like the American Mammoth Jackstock fall into this category. 🐴
Mammoth Donkeys: Height > 54 inches (137 cm) for females (jennets) and > 56 inches (142 cm) for males (jacks). Bred primarily in the USA for mule production. The American Mammoth Jackstock is the key breed. Known for their impressive stature and strength. 💪
Prominent International Breeds (Examples):
Poitou (Baudet du Poitou) - France: Famous for its distinctive long, shaggy coat (called a "cadanette") and large size. Historically crucial for breeding large mules. Critically endangered. (FAO - DAD-IS).
Andalusian (Cordobés) - Spain: A large, sturdy breed known for its elegance and historically used for mule breeding and agriculture.
Catalonian - Spain: Another large Spanish breed, robust and adaptable.
Martina Franca - Italy: A large Italian breed known for its strength and dark coat.
Ragusan - Italy (Sicily): A large, robust breed from Sicily.
Provence - France: Medium-sized, known for its hardiness.
Anatolian - Turkey: Various types, typically hardy and well-adapted to mountainous terrain. Crucial for rural transport and agriculture.
Indian Wild Ass (Subspecies): While technically a different subspecies (Equus hemionus khur), it inhabits India and is an important conservation focus. (IUCN).
Factors Influencing Breed Development: Climate, terrain, primary use (pack, draft, milk, meat, mule production), and local cultural preferences have shaped the diversity of donkey breeds.
Table 1: Representative Donkey Breeds by Size and Region
Size Category Breed Name Origin Key Characteristics Primary Traditional Use
Mammoth American Mammoth Jackstock USA Very large (54-56+ inches), powerful, refined head Mule breeding, show, driving
Large Standard Baudet du Poitou France Very large, distinctive long shaggy coat, large ears Breeding large mules (historically)
Large Standard Andalusian (Cordobés) Spain Large, sturdy, elegant build, often dark coat Mule breeding, agriculture, driving
Large Standard Martina Franca Italy Large, powerful, usually black or dark brown Agriculture, transport
Standard Common Mediterranean Widespread Variable, typically 40-48 inches, hardy Pack, light draft, companion
Standard Provence France Medium-sized (44-50 inches), very hardy, light build Pack, light draft
Miniature American Miniature USA (Sicily/Sardinia roots) < 36 inches, small, refined, friendly Companion, show, pet therapy
Miniature Sicilian Italy (Sicily) < 36 inches, ancient lineage, very hardy Companion, historically pack
IV. Fueling the Engine: The Donkey's Diet 🥬
Donkeys are hindgut fermenters, superbly adapted to utilize low-quality, high-fiber vegetation.
Natural Diet (Wild Relatives & Pastured Donkeys):
Primary: Coarse grasses, shrubs, bushes, bark, leaves, and other fibrous, often thorny, vegetation. They are highly selective browsers and grazers.
Water Needs: While adapted to conserve water, they still require regular access to clean, fresh water. Their ability to tolerate dehydration is remarkable but should never be exploited. (Maltz & Shkolnik, 1980 - Physiological Zoology).
Domestic Diet Management:
Foundation: High-quality grass hay (Timothy, Meadow hay) should form the bulk (approx. 1.5-2% of body weight daily). Straw (oat or barley) can be used as low-calorie bulk for overweight donkeys but lacks nutrients. Avoid moldy forage!
Limited Pasture: Donkeys are prone to obesity and metabolic disorders like laminitis and hyperlipaemia. Lush, rich pasture is often unsuitable. Dry lots with controlled hay access are frequently better. (The Donkey Sanctuary - Feeding Guidelines).
Concentrates (Feeds): Generally unnecessary unless the donkey is working very hard, pregnant/lactating, geriatric, or underweight. If needed, choose low-sugar, low-starch, high-fiber feeds specifically formulated for donkeys or mules. Avoid cereal/grain-based feeds common for horses. (Burden & Thiemann, 2015 - Veterinary Clinics: Equine Practice).
Mineral Supplementation: Access to a salt lick (sodium chloride) is essential. A balanced donkey-specific mineral/vitamin supplement is often crucial, especially if forage quality is poor or soil is deficient. Selenium deficiency is a known issue in some regions. (FAO - Donkey Nutrition).
Water: Constant access to clean, fresh water is non-negotiable. Automatic waterers or buckets checked and refreshed multiple times daily are essential.
Digestive Physiology: Their digestive system is slower than a horse's, allowing for more thorough fermentation of fiber. Sudden changes in diet can easily disrupt the microbial balance, leading to colic. Any dietary changes must be made extremely gradually over 10-14 days.
Obesity Crisis: Overfeeding, particularly with concentrates and rich pasture, is a major welfare issue in domestic donkeys in developed countries, leading to laminitis, hyperlipaemia (a potentially fatal condition where the body mobilizes fat too rapidly), and joint problems. (Curtis et al., 2011 - Veterinary Record).
V. Habitats and Distribution: Masters of Adaptation 🌄
Donkeys are renowned for their ability to thrive in environments where other livestock falter.
Native and Adapted Climates:
Arid and Semi-Arid Regions: Their evolutionary home. Excel in deserts, scrublands, and savannas (e.g., Sahel region, Horn of Africa, Middle East, parts of India, Mexico, Andes). Their water conservation and ability to utilize sparse vegetation are key.
Mountainous Terrain: Sure-footed and strong, they are invaluable in steep, rocky areas worldwide (e.g., Himalayas, Andes, Alps, Atlas Mountains, Greek islands).
Temperate Regions: Adapt well to cooler, wetter climates if provided with adequate shelter from rain and wind (donkeys lack a waterproof coat like some horses) and managed carefully to prevent obesity and hoof issues (e.g., UK, Ireland, parts of Europe, North America).
Shelter Requirements: While hardy, domestic donkeys require access to shelter:
Protection: From extreme weather – driving rain, cold winds, snow, and intense sun/heat. A simple three-sided shed is often sufficient.
Dry Ground: Crucial for preventing hoof problems like thrush and abscesses. Shelter provides a place to stand off wet, muddy ground.
Global Population: Estimated at around 53 million donkeys globally (FAO STAT, 2023). Major populations exist in:
Africa: Ethiopia (~8.5 million), Egypt (~5.5 million), Niger (~3.5 million), Burkina Faso (~2.5 million) – vital for rural livelihoods.
Asia: China (~5.5 million), Pakistan (~5.3 million), India (~1.5 million official, likely higher), Afghanistan (~1.7 million).
Americas: Mexico (~1.3 million), Bolivia (~0.8 million), Peru (~0.7 million), USA (~0.04 million – primarily pets/companions).
Europe: Smaller populations, often in more specialized roles or as companions (e.g., Spain, Italy, Greece, UK, Ireland).
VI. The Cycle of Life: Reproduction in Donkeys ♻️
Donkey reproduction shares similarities with horses but has distinct characteristics and challenges.
Sexual Maturity:
Jennets (Females): Typically reach puberty between 12-15 months, but best not bred until at least 3 years old to allow full physical maturity. (Gastal, 2001 - Reproduction in Donkeys).
Jacks (Males): Can be fertile by 1 year, but full sexual maturity and reliable sperm quality are usually achieved by 3 years. Early use can lead to behavioral problems.
Estrus Cycle:
Seasonality: Donkeys are generally considered seasonally polyestrous, cycling more reliably during longer daylight periods (spring/summer), especially in temperate zones. In tropical regions, they may cycle year-round. (Carluccio et al., 2007 - Theriogenology).
Cycle Length: Average 23-24 days (range 18-28 days).
Estrus (Heat): Lasts 5-9 days, characterized by receptivity to the jack. Ovulation usually occurs in the last 24-48 hours of estrus. Signs can be subtle: increased urination, winking vulva, seeking the jack.
Breeding:
Natural Covering: Requires careful management due to the jack's potentially aggressive behavior towards the jennet. Experienced handlers are essential. Jacks have a strong libido.
Artificial Insemination (AI): Increasingly used, especially for valuable breeds or biosecurity. Requires specialized techniques and often fresh or chilled semen; frozen donkey semen has lower fertility rates than horse semen. (Contri et al., 2010 - Animal Reproduction Science).
Gestation: Notably longer than horses. Averages 12 months (365-375 days), but can range from 11 to 14 months. Accurate due date prediction is challenging. (Camillo et al., 2000 - Journal of Reproduction and Fertility).
Parturition (Foaling): Usually rapid (30-60 minutes for the main stages). Most foals are born at night or early morning. Dystocia (birthing difficulties) is less common than in horses but can occur. Colostrum intake within the first few hours is critical for foal immunity.
Foal Development:
Nursing: Foals (often called "foals" or "jack foals"/"jenny foals") stand and nurse within the first 1-2 hours.
Weaning: Typically occurs between 6-9 months of age. Should be done gradually to minimize stress for both jennet and foal.
Growth: Reach mature height around 3-4 years old, though full body maturity may take longer.
Reproductive Challenges:
Lower Fertility: Donkeys generally have lower conception rates per cycle compared to horses, especially with AI using frozen semen.
Hybridization: Donkeys can interbreed with horses:
Jack + Mare = Mule (Almost always sterile)
Stallion + Jennet = Hinny (Almost always sterile)
Mules and hinnies inherit hybrid vigor but sterility due to uneven chromosome pairing.
Conservation Breeding: For rare breeds like the Poitou, overcoming low fertility and managing small gene pools are significant challenges requiring advanced reproductive technologies and careful genetic planning. (FAO - Management of Small Populations at Risk).
Table 2: Key Reproductive Parameters in Donkeys vs. Horses
Parameter Donkey (Equus asinus) Horse (Equus caballus)
Age at Puberty Jennets: 12-15 mo (Breed at 3+ yrs) Fillies: 12-18 mo (Breed at 3+ yrs)
Jacks: Fertile ~1 yr (Mature at 3 yrs) Stallions: Fertile ~1 yr (Mature 3+)
Estrus Cycle Length Avg. 23-24 days (18-28 days) Avg. 21 days (19-22 days)
Estrus Duration 5-9 days 5-7 days
Ovulation Timing Last 24-48 hrs of estrus Last 24-48 hrs of estrus
Gestation Length Avg. 365-375 days (11-14 mo) Avg. 335-342 days (11 mo)
Primary Offspring Foal (Jack foal, Jenny foal) Foal (Colt, Filly)
Hybrid Offspring Jack x Mare = Mule (Sterile) Stallion x Jennet = Hinny (Sterile)
Fertility (AI Frozen) Lower success rate Higher success rate
VII. The Indispensable Donkey: Roles in Human Society 👨🌾
The partnership between humans and donkeys is ancient and multifaceted:
Transportation & Pack Animals: Remain the backbone of rural economies in developing nations, transporting water, firewood, crops, goods, and people across challenging terrain where vehicles are impractical or unaffordable. A study in Ethiopia estimated donkeys save women and children up to 5 hours per day in water/fuel collection time. (Starkey & Starkey, 2000 - Tropical Animal Health and Production).
Agriculture: Used for plowing, tilling, weeding, threshing grain, and powering irrigation systems (e.g., noria wheels). Vital for smallholder farmers.
Guard Animals: Increasingly recognized for their effectiveness in protecting sheep, goats, and even cattle from predators like coyotes, dogs, and foxes. Their innate alertness, territoriality, and powerful kick deter attackers. (Green & Woodruff, 1988 - Sheep & Goat Research Journal).
Milk Production: Donkey milk is remarkably similar to human breast milk in composition (high lactose, low fat, high lysozyme). It's used:
Nutrition: For infants with cow's milk protein allergy (under medical supervision).
Cosmetics: High-value ingredient in soaps, creams, and lotions for its purported anti-aging and skin-nourishing properties. (Vincenzetti et al., 2008 - Current Pharmaceutical Design).
Health: Historically and in some regions currently used for its purported benefits for respiratory and gastrointestinal ailments. Research into bioactive compounds is ongoing. (Tesse et al., 2009 - Journal of Medicinal Food).
Meat and Hide: While controversial in many cultures, donkey meat is consumed in some regions (e.g., parts of China, Italy - salame d'asino, Mexico). The hide trade, particularly supplying the demand for ejiao (a Traditional Chinese Medicine gelatin), is a major welfare concern driving unsustainable slaughter, often involving theft and long-distance transport under horrific conditions. (The Donkey Sanctuary - Under the Skin Reports).
Companionship and Therapy: Growing popularity as affectionate, intelligent companions and therapy animals due to their calm demeanor. Miniature donkeys are particularly suited. ❤️
VIII. Conservation and Welfare: Facing Modern Challenges 🛡️
Despite their hardiness, donkeys face significant threats:
Threats to Wild Asses: Habitat loss, fragmentation, competition with livestock, hunting, and hybridisation with domestic donkeys push the Somali and Nubian Wild Asses to the brink of extinction. Intensive conservation efforts are critical. (Moehlman et al., 2016 - IUCN SSC Equid Specialist Group).
Domestic Donkey Welfare Challenges:
Overwork and Neglect: Common in areas of extreme poverty, leading to exhaustion, wounds, lameness, and untreated diseases.
Inadequate Nutrition/Hydration: Lack of sufficient food, poor-quality forage, or water deprivation.
Lack of Veterinary Care: Preventable diseases and injuries go untreated.
The Hide Trade: The massive, often unregulated demand for donkey skins for ejiao is causing catastrophic population declines in source countries (e.g., Kenya, Brazil, Botswana), devastating communities reliant on them, and involving extreme suffering during capture, transport, and slaughter. (FAO - The Donkey Skin Trade, 2019; The Donkey Sanctuary Reports).
Abandonment: In some developed countries, donkeys may be abandoned when no longer wanted or due to financial hardship.
Conservation Efforts:
In-situ Conservation: Protecting wild populations and their habitats in Africa through national parks and community initiatives.
Ex-situ Conservation: Breeding programs for critically endangered breeds like the Poitou donkey in Europe and North America.
Welfare Organizations: Global NGOs like The Donkey Sanctuary (UK/international), Brooke, SPANA, and many local groups work tirelessly on veterinary care, education for owners, advocacy against the hide trade, and providing sanctuaries.
Sustainable Use Advocacy: Promoting humane treatment, proper management, and recognizing the economic and social value of live donkeys to communities.
IX. Global Research Spotlight: Expanding Our Understanding 🔬
Scientific research continues to deepen our knowledge:
Behavior & Cognition: Studies confirming their complex social intelligence, long-term memory, and ability to solve problems, challenging outdated stereotypes. (Lampe & Andre, 2012 - Animal Cognition).
Thermoregulation & Physiology: Research into their remarkable adaptations for water conservation and heat tolerance, with potential insights for other species and even materials science. (McCutcheon & Geor, 2008 - Equine Veterinary Journal).
Nutrition & Metabolic Health: Ongoing research refines dietary recommendations to combat obesity and related disorders like hyperlipaemia and laminitis. (Burden et al., 2011 - Veterinary Journal).
Reproductive Technologies: Improving the success rates of AI, particularly with frozen semen, and advancing embryo transfer techniques for conservation breeding. (Camillo et al., 2019 - Animals).
Donkey Milk Science: Detailed analysis of its composition, bioactive proteins (lysozyme, lactoferrin), fatty acid profile, and potential health benefits (antimicrobial, immunomodulatory, anti-inflammatory properties). (Salimei & Fantuz, 2012 - Journal of Dairy Science).
Genomics: Mapping the donkey genome provides insights into their evolutionary history, breed relationships, genetic diseases, and potential for selective breeding. (Huang et al., 2015 - Nature Communications).
Conclusion: Honoring a Resilient Partner 🤝
The donkey, often underestimated, is a creature of profound resilience, intelligence, and quiet strength. From its origins in the African deserts to its indispensable role in global agriculture, transport, and even emerging industries like dairy and therapy, the donkey has proven its worth time and again. Understanding their unique biology, diverse breeds, specific dietary needs, adaptable habitats, and complex reproduction is crucial not only for their proper care but also for appreciating their true contribution. As they face modern challenges, particularly the devastating impact of the hide trade and the threats to wild ancestors, a global commitment to their welfare and conservation is imperative. By valuing the live donkey for its myriad contributions and ensuring its humane treatment, we honor a partnership that has shaped human history and continues to sustain millions of livelihoods worldwide. The future of this enduring equine depends on our respect, compassion, and action. 🌈🐾
Glossary
AI (Artificial Insemination): The deliberate introduction of semen into a female's reproductive tract.
Colostrum: The first milk produced after birth, rich in antibodies essential for foal immunity.
Dystocia: Difficult or abnormal birth.
Ejiao: A gelatin produced from donkey hides, used in Traditional Chinese Medicine.
Estrus: The period of sexual receptivity in the female reproductive cycle ("heat").
Hyperlipaemia: A potentially fatal metabolic disorder involving excessive mobilization of fat into the bloodstream, common in overweight or stressed donkeys.
Hindgut Fermenter: An animal that digests fibrous plant material primarily through microbial fermentation in the large intestine (cecum and colon).
Jack: Intact adult male donkey.
Jennet (or Jenny): Adult female donkey.
Laminitis: A painful and debilitating inflammation of the laminae within the hoof, often linked to diet or metabolic issues.
Mule: Hybrid offspring of a male donkey (jack) and a female horse (mare).
Hinny: Hybrid offspring of a male horse (stallion) and a female donkey (jennet).
Withers: The highest point of the back, at the base of the neck, used to measure height.
Frequently Asked Questions (FAQ)
Q: Are donkeys really stubborn?
A: No. Their behavior is cautious and self-preserving. They stop and assess situations they perceive as dangerous, which humans often misinterpret as stubbornness. Patience and understanding their nature are key.
Q: How long do donkeys live?
A: With good care, domestic donkeys regularly live 25-35 years, and some reach over 40 years. This is significantly longer than often assumed.
Q: Can I keep a donkey with my horse?
A: Yes, often very successfully! Donkeys and horses can form strong bonds. However, introduce them gradually and carefully under supervision. Ensure the donkey isn't bullied regarding food access.
Q: Why is the donkey hide trade a problem?
A: It drives unsustainable slaughter, often involving stolen donkeys, horrific long-distance transport conditions, inhumane slaughter methods, and devastates communities who rely on live donkeys for their livelihoods. It also threatens global donkey populations.
Q: Is donkey milk good for you?
A: Research shows it has a composition close to human milk (high lactose, low fat, rich in antimicrobial proteins). It's used for infants with cow milk allergies (under medical guidance) and in high-end cosmetics. More research is ongoing into its health benefits.
Q: Do donkeys need shoes like horses?
A: Generally, less frequently than horses. Their tough hooves are adapted to dry, hard ground. However, donkeys working extensively on abrasive surfaces, carrying heavy loads, or with specific hoof pathologies may need shoes or boots. Regular trimming by a qualified farrier is essential regardless.
References (Examples of Global Sources):
The Donkey Sanctuary: (https://www.thedonkeysanctuary.org.uk/) - Extensive welfare resources, research reports (e.g., "Under the Skin" series on the hide trade), husbandry guides.
Food and Agriculture Organization of the United Nations (FAO):
DAD-IS (Domestic Animal Diversity Information System): Breed databases.
STAT: Global livestock population data.
Reports: The Donkey Skin Trade: Implications for Livestock Policy and Sector Development (2019).
Donkey Utilization and Management in Ethiopia.
Brooke: (https://www.thebrooke.org/) - International animal welfare charity focusing on working horses, donkeys, and mules. Research and field programs.
International Union for Conservation of Nature (IUCN) Red List: Assessments for Equus africanus (African Wild Ass).
Peer-Reviewed Journals: Journal of Equine Veterinary Science, Theriogenology, Animal Reproduction Science, Equine Veterinary Journal, Veterinary Record, Animal Behaviour, Journal of Dairy Science, PLOS ONE, Nature Communications, Science.
Key Research Papers (Examples):
Beja-Pereira, A., et al. (2004). Science - Donkey domestication origins.
Burden, F., & Thiemann, A. (2015). Veterinary Clinics: Equine Practice - Donkey nutrition and metabolic disorders.
Camillo, F., et al. (2000). Journal of Reproduction and Fertility - Donkey gestation length.
Carluccio, A., et al. (2007). Theriogenology - Donkey estrus cycle.
Contri, A., et al. (2010). Animal Reproduction Science - Donkey AI.
Curtis, G.C., et al. (2011). Veterinary Record - Hyperlipaemia in donkeys.
Gastal, M.O. (2001). Chapter in Reproduction in Donkeys.
Huang, J., et al. (2015). Nature Communications - Donkey genome.
Moehlman, P.D., et al. (2008). Equids: Zebras, Asses, and Horses. Status Survey and Conservation Action Plan. IUCN/SSC Equid Specialist Group.
Proops, L., et al. (2009). Animal Behaviour - Donkey cognition.
Salimei, E., & Fantuz, F. (2012). Journal of Dairy Science - Donkey milk.
Smith, D.G., & Pearson, R.A. (2005). Equine Veterinary Journal - Thermoregulation.
Starkey, P., & Starkey, M. (2000). Tropical Animal Health and Production - Role of donkeys in transport.
Vincenzetti, S., et al. (2008). Current Pharmaceutical Design - Donkey milk proteins.
