A Tale of Two Antelope: how different approaches to conservation can save a species

In December 2023, two conservation stories made headlines only a couple of days apart. They appeared remarkably similar in that both announced major recovery in the wild populations of rare antelope. The first was a dramatic increase in the population of scimitar-horned oryx (Oryx dammah) reintroduced to the dry grasslands of Chad. Perhaps the most iconic antelope of the Sahara, the species was declared extinct in the wild by the IUCN in 2000, with all remaining individuals making up the captive breeding population in zoos and private reserves. In between 2016 and 2022, 285 oryx derived from this breeding programme were released into a fully wild setting in Chad, and have bred prolifically. As such, the IUCN tentatively downgraded their conservation status to endangered.

Breaking just a couple of days later was the news that saiga (Saiga tatarica) had also dramatically increased in population, and had been downgraded from critically endangered to near threatened. Saiga are a bizarre remnant of the Pleistocene ice ages, having evolved on the vast, dry grasslands of Eurasia alongside mammoths and woolly rhinoceros, and are not especially closely related to any living antelope. Their population has fluctuated several times over the last century, but this most recent increase occurred primarily in Kazakhstan, where fewer than 200,000 wild saiga increased to over a million in under a decade. Kazakhstan has repeatedly extended their complete ban on saiga hunting, first introduced in 1999, and now hosts the bulk of the global population. 

Both stories appear similar in their ultimate increase of wild antelope numbers, but also highlight two very different means of conservation practice, with the oryx making a comeback due to the captive breeding efforts of zoos, while saiga increased in number due to the legislative protection of their habitat and their lives.

The reintroduction of scimitar-horned oryx into Chad is about as good an example of the role zoos play in conservation as one is likely to find. They disappeared from the wild in the 1980s following a rapid population decline, with the last known individual being shot in Chad in 1989. The species was saved from total extinction by their sizable captive population, which today includes roughly 3,500 individuals in Australasian, European and North American zoos. 

The first attempt to reintroduce oryx to their native range occurred in 1985, wherein 10 individuals from Edinburgh and Marwell Zoos were released into a fenced reserve in Tunisia. Three more releases took place in both Tunisian and Senegalese reserves in 1999 and 2007, each led by Marwell, and today the semi-wild population in Tunisia numbers more than 200 individuals. However, none of these efforts resulted in establishment of a truly wild herd, as each had taken place in a geographically-constrained, fenced area. It wasn't until 2016 that wild oryx would be seen again.

More than 260 animals from the captive population, including individuals from ZSL Whipsnade Zoo, were transferred first to Abu Dhabi and then on to Chad, where the first herd was released in August of 2016 following a period of acclimatisation. Eight additional herds have been released since then, which include 22 calves born in the holding enclosure. Since the first oryx were released, more than 330 calves have been born in the wild. While it is likely many will not survive to reproductive age, it is this huge increase in wild numbers and formation of a genetically viable population that has prompted their reassessment by the IUCN.

Wild populations of saiga have fluctuated a lot over the last century. By the time protective measures were established in the 1910s, as few as a thousand individuals may have remained. Numbers subsequently increased to 1.8 million individuals in Russia and Kazakhstan by the middle of the century, leading to a lifting of their legal protection. Hunting for meat and increased anthropogenic use of their habitat meant saiga numbers began to fall again in the late 20th century. This was exemplified by poaching for their horns, which greatly reduced the number of males in the population and slowed their breeding rates. In just 3 decades their population reduced by 98.5%, so by the turn of the millennium only 26,000 were left.

Saiga have historically proven difficult to care for in captivity. This may be attributed to complex husbandry needs, at least in comparison to other antelope, but it is one of the inevitable facts of keeping animals in captive settings like zoos and safari parks that some species just don't tend to do very well outside of their natural habitat. Many places have attempted to keep saiga, especially throughout the 20th century, but a combination of low birth rates, short lifespans and the need to import individuals meant that an ex-situ captive breeding programme was never established, even after they were declared critically endangered in 2002.

In contrast to the scimitar-horned oryx, conservation of the saiga would have to rely almost entirely on in-situ conservation measures. This largely involved the establishment and maintenance of protected areas in their native range, namely in Russia, Mongolia, Kazakhstan and Uzbekistan. Semi-captive breeding herds were also established in these countries, as well as about 700-800 individuals in China and Ukraine. In 1999, Kazakhstan legislated a complete ban on the hunting of saiga, which was extended six times through the 21st century. It is these protections that lead to the exponential growth in the Kazakhstani population over the last 25 years. Other protections granted in Russia and Mongolia have also increased their own populations to several thousand individuals in each country.

Conservation efforts are often talked about as being either in situ or ex situ. In situ projects take place within a given species' native habitat or range, including areas from which they have been extirpated, while ex situ projects take place elsewhere, such as zoos or specialist breeding centres, even those in countries the species can be found wild in. However, neither the recent success of the oryx nor the saiga can be exclusively attributed to either one measure. 

The oryx were maintained by a captive population from the 1980s to the present day, made up of zoos and private reserves around the world, and individuals bred from these settings were released first into semi-wild areas near to their former range, and later fully into the wild in their native range. Likewise, saiga have been predominantly kept from extinction by protective measures on the steppes of Central Asia, but their numbers were supplemented by the efforts of specialist centres in their native range and in neighbouring countries. In both cases, a hybrid approach to conservation has massively increased the wild numbers of their respective antelope, so it seems obvious that using both in situ and ex situ approaches, at least where possible, may yield the best results when it comes to saving species. 

Both species of antelopes can already be considered success stories, though both are still under threat of extinction should some major disaster befall them, or measures to protect them be made more lax. Saiga have almost gone extinct twice already in just the last century, and while they and the oryx have proven their numbers can bounce back, this can only happen when conservation efforts are prolonged. If efforts to preserve these two antelope are not continued, they may face the same threats of extinction once again. 

Sources

Glázer, G. (2017) An overview of the saiga antelope (Saiga tatarica) in captivity in Europe and the United States. Available at: https://www.saigaresourcecentre.com/sites/default/files/an_overview_of_the_saiga_antelope_in_captivity_in_europe_and_the_us_glazer_final.pdf.

IUCN SSC Antelope Specialist Group (2023) Oryx dammah, The IUCN Red List of Threatened Species. doi: https://dx.doi.org/10.2305/IUCN.UK.2023-1.RLTS.T15568A197393805.en.

IUCN SSC Antelope Specialist Group (2023) Saiga tatarica, The IUCN Red List of Threatened Species. doi: https://dx.doi.org/10.2305/IUCN.UK.2023-1.RLTS.T19832A233712210.en.

Marwell Zoo (no date) Scimitar-horned oryx. Available at: https://www.marwell.org.uk/animals/scimitar-horned-oryx/. 

Sahara Conservation (2023) 'Milestone: the scimitar-horned oryx downlisted from Extinct in the Wild to Endangered by IUCN', Sahara Conservation, 11 December. Available at: https://saharaconservation.org/milestone-the-scimitar-horned-oryx-downlisted-from-extinct-in-the-wild-to-endangered-by-iucn/.

RZSS (no date) Scimitar-horned oryx. Available at: https://www.rzss.org.uk/conservation/conservation-projects/scimitar-horned-oryx.

Ualikhanova, A. (2023) 'Saiga Crisis: Farmers Seek Regulations Amid Population Surge in Kazakhstan', The Astana Times, 8 October. Available at: https://astanatimes.com/2023/10/saiga-crisis-farmers-seek-regulations-amid-population-surge-in-kazakhstan/#:~:text=In%201999%2C%20Kazakhstan%20instituted%20a,steadfast%20commitment%20to%20saiga%20preservation.

Wetzel, C. (2022) 'Saiga antelopes have increased 10-fold after mass die-off in 2015', New Scientist, 12 August. Available at: https://www.newscientist.com/article/2333567-saiga-antelopes-have-increased-10-fold-after-mass-die-off-in-2015/.

ZSL (2023) Extinct in the wild oryx brough back from brink of extinction. Available at: https://www.zsl.org/news-and-events/news/oryx-downlisted-conservation-success.