About one million years ago, multiple ungulate species, including at least three Giraffe species, spread over the African continent along with the emerging savanna/woodland biome (Mitchell and Skinner 2003, Robinson 2011). But between 600,000 and 800,000 years ago, only a single species, Giraffa camelopardalis, is found in the fossil record. The adaptive radiation of Giraffes across Africa occurred during a period of environmental instability, climate change, and geological upheavals that produced distinctive lineages living in mostly disconnected areas of Africa (Bock et al. 2014, Fennessy et al. 2013, Groves and Grubb 2011, Brown et al. 2007, Hassanin et al. 2007). Continued natural, as well as human-induced, changes in habitat have yielded a suture zone in Eastern Africa, as well as possibly Northern and Southern Africa, that impedes our ability to mark specific boundaries between the various kinds of Giraffes. Hence, Giraffes evolved an ability to adapt to a variety of ecosystems and, as they did so, lineages emerged in different regions where they evolved distinctive characteristics, but whether these traits are significant enough to consider the differences as species or subspecies is unclear at the moment.

Giraffes are most often found in savanna/woodland habitats, but range widely throughout Africa. They are browsers that subsist on a variable diet that includes leaves, stems, flowers, and fruits. They do not need to drink on a daily basis. Across the continent, detailed records of Giraffe feeding ecology have noted that each population has a very diverse diet of up to 93 different species, but that usually a half dozen plant species comprise at least 75% of the diet. Acacia is fed on in high proportions wherever Giraffes are found, but during the dry season, the preferred plant species varies by location. Faidherbia, Boscia, Grewia, and Kigelia have all been identified as the most common plant species in the diet of giraffes in the dry season in different locations. Some populations have seasonal shifts in home ranges.

This species is the world's tallest land mammal and remains widespread across southern and eastern Africa, with smaller isolated populations in west and central Africa. Giraffes inhabit eighteen African countries and have been reintroduced to three others (Malawi, Rwanda, and Swaziland). Giraffes from South Africa have been introduced to Senegal. Giraffes appear to have gone extinct in at least seven countries (Burkina Faso, Eritrea, Guinea, Mali, Mauritania, Nigeria and Senegal). Giraffes have adapted to a variety of habitats, ranging from desert landscapes to woodland/savanna environments, but live in non-continuous, fragmented populations across sub-Saharan Africa.

Table 1 in the Supplementary Material summarizes the current conservation status of the nine subspecies. West African Giraffes (Giraffa c. peralta) are limited to an isolated population in the south-western corner of Niger and in 2008 this subspecies was categorized as Endangered on The IUCN Red List (Fennessy and Brown 2008). In Central Africa, G. c. antiquorum inhabit Cameroon, Central African Republic, Chad, Democratic Republic of Congo and South Sudan. East Africa is home to four subspecies of Giraffes, with three of them living in Kenya. G. c. camelopardalis occurs in both South Sudan and Ethiopia, although information regarding the area of occupancy of this population of Giraffes is limited. Giraffes living in north-eastern Kenya, and across the borders in south-eastern Ethiopia and south-western Somalia, are G. c. reticulata, those living in Uganda and introduced to central and southwest Kenya are categorized as G. c. rothschildi – and in 2010 this subspecies was categorized by the IUCN Red List as Endangered (Fennessy and Brenneman 2010), and those in southern Kenya, along with large tracts of Tanzania, are considered to be G. c. tippelsckirchi. In Southern Africa, the population living in the Luangwa Valley, Zambia, is G. c. thornicrofti. Angola, southern and northern Botswana, Mozambique, northeast Namibia, South Africa, and southwest Zambia are home to G. c. giraffa, whilst G. c. angolensis occurs in central Botswana and Namibia. Confusion still exists as to whether the giraffes in northern Botswana, north-eastern Namibia, south-western Zambia and north-western Zimbabwe are G. c. angolensis or G. c. giraffa, and for purposes of establishing the total population counts and trends here are lumped into G. c. angolensis.

Given that some Giraffe populations are increasing, some are decreasing, and one seems to be stable, the conservation actions most useful and appropriate for Giraffes will differ as a function of Giraffe population dynamics, ecological stability, national policies, and legislation. Giraffes are subject to various degrees of legal protection in their range states. Large populations occur in national protected areas and on private farms, but many populations also exist in unprotected and communal areas. The main threats to the conservation of Giraffe populations are habitat loss, encroachment and conversion, and poaching.
 
Conservation measures typically include habitat management and protection through law enforcement and community based conservation initiatives. Successful protection of habitat and cessation of habitat encroachment with the use of fences and border protection can result in large herds building up within an area. The continued growth of these populations however is limited by the ability of that ecosystem to support a particular number of Giraffes due to space, water and forage availability (i.e., limited carrying capacity).

In Niger, conservation projects and targeted community education and awareness programs have facilitated the re-bounding of the Giraffe population from a low of 49 individuals in the absence of official protected areas. However, habitat loss and drought remain as significant threats in this area. Importantly, the government was the first and remains the only range state to have developed a National Giraffe Conservation Strategy, and through this the conservation of the species has increased nearly eightfold in twenty years.

Kenya is finalising a National Giraffe Conservation Strategy which seeks to identify and implement a number of conservation interventions to conserve the three Giraffe subspecies (Giraffa reticulata, G. rothschildi, G. tippelskirchi) in the country. Rothschild’s Giraffes are accorded full protection under the Kenyan Wildlife (Conservation and Management) Act (Chapter 376) and in the Republic of Uganda Giraffe are protected under the Game (Preservation and Control) Act of 1959 (Chapter 198) and listed under Part A of the First Schedule of the Act as animals that may not be hunted or captured.

Throughout Eastern and Southern Africa, an increasing number of Giraffe translocations have repopulated former habitats with Giraffes, fostering wildlife enterprises including tourism and consumptive use, and maintaining genetic diversity given small, enclosed and fragmented populations.

Although one of the smallest populations in Africa lives in the Luangwa Valley, Zambia, the population has been stable for a number of years, so intervention as a conservation action is probably not warranted. Instead, continued monitoring of the population, combined with efforts to limit and control mineral extraction and land conversion, would be useful.

In Southern Africa, private ownership of Giraffes sometimes facilitates the gene flow between populations as animals are bought, sold and traded between farms. Perhaps a more controlled and systematic pattern of Giraffe translocations would help in the conservation of Giraffes.