Researchers have discovered that giraffe should not just be grouped under a single species, but, rather, four genetically isolated species.
The most inclusive genetic analysis on the world’s tallest mammal has yielded surprising results. Upon closer examination, researchers have discovered that giraffe should not just be grouped under a single species, but, rather, four genetically isolated ones. According to a press release, the genetic differences between the species are as great as those that can be witnessed between brown bears and polar bears.
The study was a collaborative effort between Dr. Axel Janke, geneticist at the Senckenberg Biodiversity and Climate Research Centre and Goethe University in Germany and Dr. Julian Fennessy of the Giraffe Conservation Foundation (GCF) which is based in Nambia.
When speaking of their findings, Dr. Janke said, “We were extremely surprised, because the morphological and coat pattern differences between giraffe are limited. Giraffe are also assumed to have similar ecological requirements across their range, but no one really knows, because this megafauna has been largely overlooked by scientists.”
In 1758, the giraffe made its first debut within the text of Systema Naturae, a work that was written by Carolus Linnaeus, a Swedish botanist, and essentially introduced taxonomy to the world. According to the study, Linnaeus based the description pertaining to giraffe on the Nubian giraffe, which is the nominate subspecies. (Interestingly, Dr. Linnaeus, himself, had never seen a living giraffe.)
After that, researchers based much of their information on the features of the giraffe (spots, ossicones, or horn-like protuberances on the head) as well as “geographic distribution,” according to the study. However, study authors write, “geographical distribution of some giraffe subspecies remains uncertain” and “identification and classification of the nominotypical Nubian giraffe was even less certain.”
Giraffe, as a whole, have dramatically declined over the last three decades, according to the press release. Where there were at least 150,000 giraffe individuals, there are less than 100,000 to date, which makes conservation efforts critical to their survival. According to the researchers, little research has been done on the world’s tallest mammal in comparison to other larger animals such as rhinoceroses and elephants.
In an effort to fill this research void, the researchers set out to perform a genetic test of giraffe in order to better gauge the similarities and differences between giraffe living in various geographical areas throughout Africa. In addition, the researchers sought to understand “whether past translocations of giraffe individuals had inadvertently ‘mixed’ different species or subspecies, and, if so, what should be done in future translocations of giraffes into parks or other protected areas.” The samples that the researchers took were from all nine of the giraffe subspecies that have been officially recognized over the years, including giraffe individuals from the nominate subspecies, the elusive Nubian giraffe, Giraffa camelopardalis camelopardalis.
The researchers learned there were four genetically isolated species of giraffe and as a result, feel that they should be recognized as such. The four species are: the northern giraffe, or Giraffa camelopardalis, (which contains three different subspecies within it: Kordofan, or G. c. antiquorum, Nubian, or G. c. camelpardalis, and West African giraffe, or G. c. peralta), the southern giraffe, or Giraffa giraffa (which contains two different subspecies within it: Angolan, or G. g. angolensis, and South African giraffe, or G. g. giraffe), the reticulated giraffe, or Giraffa reticulata, and the Masai giraffe, or Giraffa tippelskirchi.
An updated assessment has been submitted for review by the IUCN Red List by the International Union of Conservation of Nature and Natural Resources (IUCN) Species Survival Commission (SSC) Giraffe and Okapi Specialist Group due to the species’ declining numbers over recent years. The IUCN’s Red List of threatened species “has evolved to become the world’s most comprehensive information source on the global conservation status of animal, fungi, and plant species,” according to the official website. The IUCN Red List can be used as a tool to inform action in relation to conservation efforts.
When speaking of the implications of their findings, Dr. Fennessy said, “With now four distinct species, the conservation status of each of these can be better defined and in turn hopefully added to the IUCN Red List in time. Working collaboratively with African governments, the continued support of the Giraffe Conservation Foundation and partners can highlight the importance of each of these dwindling species, and hopefully kick start targeted conservation efforts and internal donor support for their increased protection. As an example, northern giraffe number less than 4,750 individuals in the wild, and reticulated giraffe number less than 8,700 individuals-as distinct species, it makes them some of the most endangered large mammals in the world and require doubling of protection efforts to secure these populations.”
The researchers hope that their findings can be used to increase conversation efforts on a global level. The Giraffe Conservation Foundation is dedicated to doing this, having monitored the decline of the species throughout Africa over the years as well as working to identify the biggest threats that the species faces. Currently, the researchers are taking a closer look at gene flow and how it differs between the different species.