Introduction
Giraffes (genus *Giraffa*) are large even-toed ungulate mammals native to Africa. They are the tallest living land animals and the largest ruminants on Earth. Giraffes are classified in the family Giraffidae, along with their closest living relative, the okapi. Traditionally, giraffes were considered a single species, *Giraffa camelopardalis*, with nine subspecies. However, recent research suggests dividing them into four living species with seven subspecies, distinguishable morphologically by their coat patterns. Six fossil species from the genus *Giraffa* are also known.
Etymology
The name "giraffe" comes from the Arabic word *zirāfah*, which may have originated from a Sub-Saharan African language. The old English name "camelopard" comes from the Greek *kamēlopárdalis*, a combination of "kamel" (camel) and "pardalis" (leopard), referring to their camel-like shape and leopard-like coloration.
Taxonomy and Evolution
Giraffes and okapis are the only surviving members of the family Giraffidae within the order Artiodactyla. They are ruminants in the clade Pecora. A 2019 genome study placed Giraffidae as a sister taxon to Antilocapridae, with an estimated divergence over 20 million years ago.
The family Giraffidae was once more widespread, with more than 10 fossil genera described. Neck elongation began early in the giraffe lineage, with vertebrae near the skull elongating first, followed by lower vertebrae. Early ancestors such as *Canthumeryx* lived 25–20 million years ago and resembled antelopes. *Giraffokeryx* appeared 15–12 million years ago in the Indian subcontinent, resembling either okapis or small giraffes. *Samotherium* was an important transitional fossil with a cervical vertebra length between modern giraffes and okapis. *Bohlinia*, which appeared in Southeast Europe 9–7 million years ago, is the direct ancestor of *Giraffa*. Climate change caused the extinction of Asian giraffes, while African giraffes survived and evolved into new species. Modern giraffes appeared around 1 million years ago in East Africa during the Pleistocene.
Species and Subspecies
Carl Linnaeus originally classified giraffes as a single species in 1758. A 2007 genetic study using mitochondrial DNA suggested at least six lineages that could be recognized as species. A 2011 study using morphological analysis and the phylogenetic species concept explained eight living giraffe species. A 2016 study suggested four species that did not exchange genetic information for one to two million years. A 2021 study using whole-genome sequencing supported the existence of four species and seven subspecies. The four widely accepted species are:
* Northern giraffe (*Giraffa camelopardalis*): Includes the Kordofan, Nubian, and West African subspecies.
* Reticulated giraffe (*Giraffa reticulata*): Known for its distinct red-brown polygonal pattern.
* Masai giraffe (*Giraffa tippelskirchi*): Includes the Masai and Thornicroft subspecies.
* Southern giraffe (*Giraffa giraffa*): Includes the Angolan and South African subspecies.
Anatomy
Adult giraffes stand 4.3–5.7 meters tall, with males taller than females. The average weight is 1,192 kg for adult males and 828 kg for females. Although they have long necks and legs, their bodies are relatively short. Their skin is mostly gray or chestnut and can reach a thickness of 20 mm. Their tail is 80–100 cm long, ending in a dark tuft of hair and used for defense against insects.
The spot pattern on their fur is unique to each giraffe and functions as camouflage in the savanna. Spots can be orange, brown, or nearly black, surrounded by bright hairs. Males become darker as they age. Spots may also play a role in thermoregulation because the skin beneath them has a complex network of blood vessels and large sweat glands.
Head
Both sexes have structures called ossicones, which can reach 13.5 cm. Ossicones are formed from cartilage that hardens, covered with skin, and fused with the skull bones. Adult male ossicones are usually bald and knobbed at the end, while females and young have tufts of hair. Giraffes have good color vision, sharp hearing, and a sensitive sense of smell. Their tongues are 45 cm long, black in color to protect from sun exposure, and can efficiently grasp leaves.
Neck
Giraffes have very long necks, reaching up to 2.4 meters, resulting from uneven elongation of cervical vertebrae, not an increase in the number of vertebrae. The neck is typically at a 50–60-degree angle. Although long, the giraffe's neck only has seven cervical vertebrae, like other mammals. The giraffe's cardiovascular system has adapted to pump blood to the high brain, with twice the blood pressure of ordinary mammals.
Behavior and Ecology
Giraffes usually inhabit savannas and woodland areas. Their main diet consists of leaves, fruits, and flowers of woody plants, especially acacia species, which they reach at heights inaccessible to other terrestrial herbivores. Lions, leopards, hyenas, and African wild dogs may prey on giraffes.
Giraffes live in female-related groups and their young, or in bachelor groups of unrelated adult males. They are social and can gather in large groups. Males establish social hierarchies through "necking," a contest using the neck as a weapon. Dominant males gain access to females, who are solely responsible for raising their young.
Conservation
Giraffes have gone extinct in many parts of their former range. They are still found in many national parks and protected areas. An estimate from 2016 showed there were approximately 97,500 wild giraffes. More than 1,600 were kept in zoos in 2010. The overall conservation status of giraffes is Vulnerable (Vulnerable) according to the IUCN, although some subspecies such as the West African giraffe are classified as Critically Endangered.
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*Original source: [en.wikipedia.org](https://en.wikipedia.org/wiki/Giraffe)*