Two subspecies have been traditionally accepted: T. g. gelada and T. g. obscurus (Grubb et al. 2003; Groves 2005). According to a preliminary review by Gippoliti (2010), the nominal form is limited to north of Lake Tana and west of the Takkazzé River, i.e. around the Simien Massif. Theropithecus gelada obscurus is found south of Lake Tana and east of the Takkazzé River. East of the Rift Valley in eastern Arsi, a genetically distinct and probably new taxon (T. gelada ssp. nov.) was discovered in 1990 (Belay and Mori 2006, Shotake et al. 2016). The Arsi Gelada has brighter and more golden-coloured hair than T. g. gelada and T. g. obscurus (Mori and Belay 1990, Gippoliti 2010, A. Mekonnen pers. obs. 2011). The Arsi Gelada also inhabits a drier habitat and occurs at lower altitudes (1,800–2,400 m asl) (Mori and Belay 1990, Abu et al. 2018) than Geladas elsewhere (Dunbar 1998, Beehner et al. 2007, Fashing et al. 2014).

Although Theropithecus gelada has a large geographic range, its numbers are suspected to be declining. Major threats to Geladas include the conversion of their habitat into farmland, grazing land and human settlements, as well as the climate change impacts (Dunbar 1998, Beehner et al. 2007). However, in the absence of more detailed data regarding current geographic range and demographic trends, the species remains listed as Least Concern.

Theropithecus gelada is restricted to Afroalpine grasslands adjacent to deep gorges and cliffs in the Provinces of Tigray, Begemdir (Gondar), Wollo, Shoa and Arsi at altitudes between 1,800 and 4,400 m asl (Jablonski 2005, Gippoliti 2010). The Blue Nile Gorge and the upper Wabe Shebelle Valley (east of the Bale Massif) mark the western and southeastern boundaries of the range, respectively.

Two subspecies T. g. gelada and T. g. obscurus occur in Begemdir, Tigray, Wollo and Shoa Provinces, west of the Rift Valley, while a possible third undescribed subspecies, T. gelada ssp. nov., is found along the Wabi-Shebeli River in Arsi Province, east of the Rift Valley. T. g. gelada is found north of Lake Tana and west of the Takkazzé River, while T. g. obscurus is found south of Lake Tana and east of the Takkazzé River.

Geladas are widespread throughout much of their present range, although they are probably not as abundant as they were in the 1970s, when an aerial survey of the central Ethiopian Highlands yielded a population estimate of 440,000 individuals (Dunbar 1977). A concurrent alternative estimate based on known ground densities from a small proportion of the Gelada’s geographic range and the total area of gorge face on the plateau yielded a figure of 884,000 (Dunbar 1977). Detailed ground surveys at five sites yielded overall densities varying between 15 and 69 animals/km², although densities of animals within their home ranges typically reached 70–80/km² (Dunbar 1977). A recent estimate for what is believed to be the largest remaining population of Geladas, in and around Simien Mountains National Park, was ~4,300 individuals, down from ~10,000 individuals in the 1970s (Beehner et al. 2007, Bergman and Beehner 2013).

While recent habitat conversion to farming and grazing lands has undoubtedly adversely affected the Afroalpine grassland habitats of Geladas (Fashing and Nguyen 2016), only further comprehensive surveys will reveal the extent to which Gelada populations across the highlands have changed since the 1970s.

Geladas are associated with Afroalpine grasslands and adjacent rocky gorges and precipices (Bergman and Beehner 2013). This species feeds mainly on the flat margins of high grass plateaus, known locally as high Wurch or Puna grassland steppe, with Agrostis and Festuca grasses and giant Lobelia groves. Gelada bands consist of 30–289 animals, subdivided into 5–26 one-male units (Bergman and Beehner 2013, Abu et al. 2018). Bands keep within 2 km of the escarpment edges, where they retreat at night to sleep or if alarmed (Fashing & Nguyen 2016). Typical annual home-range size for Geladas is 9–12 km² (Hunter 2001, Moua 2015). Geladas are poor tree-climbers and are almost entirely terrestrial, partly a consequence of their unusual dietary specialization as a grazer (Dunbar 1983).

Geladas feed primarily on the leaves of graminoids (grasses and sedges) and also forbs (Fashing et al. 2014, Abu et al. 2018, Jarvey et al. 2018). They also excavate and consume subterranean foods including roots, corms, tubers and rhizomes (Fashing et al. 2014, Abu et al. 2018, Jarvey et al. 2018), especially during the dry season when green vegetation is less abundant (Fashing et al. 2014, Jarvey et al. 2018). Invertebrates are eaten opportunistically (Fashing et al. 2010, 2014), and cereal crops may be taken where agriculture encroaches onto the Geladas' habitat (Abu et al. 2018, Jarvey et al. 2018).

The overall range of the Gelada is being eroded by agricultural expansion resulting from rapid human population growth in the Ethiopian highlands. Conversion of Gelada habitat to farmland and livestock grazing is common (Bergman and Beehner 2013) and soil erosion is a serious problem throughout the region (Nyssen et al. 2015). Grazing pressure is intense, and competition from domestic livestock has forced the Gelada to remain on the less productive gorge slopes in some areas (e. g. eastern Arsi) (Abu et al. 2018). Gelada densities are considerably lower in heavily populated areas than in undisturbed habitats (R. Burke, pers. obs.).

Geladas are also harassed, shot or hunted with dogs as crop pests (R. Burke, pers. obs.) and occasionally sold locally as pets (Bergman and Beehner 2013). In the past, Geladas were trapped for zoos though this practice no longer occurs. Also, in the past, adult male numbers were reduced as a result of selective shooting for their capes of hair, which were made into ceremonial costumes used by the Oromo people (Dunbar 1977). The extent of this practice today is unknown. There are also historic records of Gelada capes being made into fur hats for tourists (Dunbar 1977).

Government-sanctioned trophy hunting of Geladas by tourists is currently allowed in controlled hunting areas, although the extent and impact of this practice are unknown.

Parasitic swellings caused by tapeworms (Taenia serialis) are a major cause of death in some Gelada populations (Nguyen et al. 2015, Schneider-Crease et al. 2017).

Climate change poses a long-term threat to Geladas, especially for populations inhabiting higher elevations, where agriculture has previously been impossible or uncommon (Dunbar 1998).

Limited information is available on the extent of general use and trade in Geladas.
Hunting of Geladas has been forbidden in Ethiopia’s protected areas since the 1960s. However, hunting of Geladas is permitted in designated controlled hunting areas, although the extent and impact of this practice are unknown.

Furthermore, in Shoa, adult T. g. obscurus males have traditionally been hunted by Oromo men and their skins worn as headdresses and capes worn during ceremonies (Dunbar 1977, 1993). The extent and impacts of this practice today warrant investigation.

Both the Orthodox Christian and Muslim faiths practiced widely in Ethiopia forbid the consumption of primates.

This species is listed on Appendix II of CITES and as Class A under the African Convention.

Approximately 4,300 Geladas inhabit Simien Mountains National Park (a UNESCO World Heritage Site) in Begemdir, representing what is believed to be the largest remaining population (Beehner et al. 2007). Geladas are also formally protected in the recently established Borena Sayint National Park, South Wollo, and they receive local protection in several community conservation areas (e.g., Guassa, North Shoa and Abune Yosef, North Wollo).

It is recommended that formal protection be given to the Wabi Shebelle and Robe Gorges which are occupied by the unique Geladas that occur east of the Rift Valley. There is also an urgent need for further research to resolve the intraspecific taxonomy of Geladas, determine the remaining population numbers and distributions of the different subspecies, and identify the most important locations for Gelada conservation.