Suraud J.-P.,CNRS Biometry and Evolutionary Biology Laboratory |
Fennessy J.,Giraffe Conservation Foundation |
Bonnaud E.,University Paris - Sud |
Issa A.M.,Direction de la Faune |
And 2 more authors.
ORYX | Year: 2012
Abstract The West African giraffe is a genetically unique population represented only by the subspecies Giraffa camelopardalis peralta, categorized as Endangered on the IUCN Red List. These giraffes live outside protected areas, without natural predators and share their habitat with local people and their livestock. This study provides demographic data on this poorly studied megaherbivore and documents its recovery. We analysed the results of photo-identification censuses from 1996 to 1999 (count data) and from 2005 to 2008 (count and demographic data). From 1996 to 1999 the annual growth rate was c. 19% because of an unbalanced population structure after a period of severe poaching. From 2005 to 2008 an annual growth rate of c. 12-13% was estimated from both count data and demographic parameters. This value fits with the maximum growth rate calculated for a browser species based on the allometric relationship linking growth rate and body mass. During the period 2005-2008 adult and subadult females had a constant survival rate of 0.94 and a constant recapture rate of 0.97. Annual calf survival rate was 1. Observed sex ratio at birth was 0.57 and mean reproductive success was 0.257. Generation time was estimated to be 9.66 years. This spectacular population growth was mostly attributed to the absence of predators and the ongoing monitoring to limit illegal hunting. © 2012 Fauna & Flora International. Source
News Article | September 9, 2016
For quite some time, giraffes were all thought to belong to a single species that was divided into several sub-species. However, as it turns out, we've not been entirely accurate about the world's tallest land animal from the very beginning. In a recent study published in the journal Current Biology, it has been revealed that, rather than one species of giraffe, which is split up into several sub-species, there are actually four species of the animal, mirroring the genetic differences observed in polar bears and brown bears. "We were extremely surprised," said conservationist Julian Fennessy, co-founder of the Giraffe Conservation Foundation and lead author of the study. He also noted that the conservation implications are immense, and that their findings will hopefully help put giraffe conservation on the map. To be fair, there were already indications that all of these giraffes could be different species, but there was nothing distinct enough about them that would definitively prove it. For example, the reticulated giraffe of Somalia, with its polygonal, liver-colored spots, can be easily distinguished from the Rothschild's giraffe of Uganda and Kenya, with patches that are not as sharply defined. Similarly, while the Rothschild's giraffe and Masai giraffe of Kenya and Tanzania are similarly marked, a close look at their skulls reveals that the former has five ossicones rather than the usual three — in fact, this feature is unique to the Rothschild's giraffe. However, it wasn't until the Giraffe Conservation Foundation was looking into the potential results of different giraffe subspecies mixing together when they're moved into protected areas, that they realized there was more to giraffes than just their looks. Following a process that took almost seven years, during which time 190 tissue samples were collected, an analysis of nuclear genetic markers and mitochondrial DNA revealed that giraffes can effectively be divided into four species: the southern giraffe (Giraffa giraffa), which has a population of about 52,000; the Masai giraffe (Giraffa tippelskirchi), with an approximate population of 32,500; the reticulated giraffe (Giraffa reticulata), which numbers to about 8,700; and the northern giraffe (Giraffa camelopardalis), with about a 4,750 population. While monumental, the discovery also revealed something rather disconcerting: the reticulated giraffe and northern giraffe are in a rather precarious position. Though not considered endangered, they are dangerously close to that point, and these results should encourage the International Union for the Conservation of Nature (IUCN), which classifies giraffes as a single species, to take a stronger stance in their protection. "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," Fennessy said in a press release. Fennessy said the biggest threats to the giraffe population include destruction of their habitat due to human population growth as well as poaching for bush meat, tail hair and "medicinal" parts. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | September 10, 2016
Giraffes appear to be one single creature but findings of a new study have revealed that there are actually four different species of the long-necked mammals. Geneticist Axel Janke, from the Senckenberg Biodiversity and Climate Research Centre and Goethe University in Germany, said that the findings change the status of the animals in terms of how endangered their species are. About a third of the giraffe population was lost over the past three decades alone but the International Union for Conservation of Nature (IUCN) does not consider giraffes as endangered. They remain classified as least concern. The discovery that the animal is composed of at least four different species, which was published in the journal Current Biology on Thursday, Sept. 8, can have crucial implications in giraffe conservation campaigns. Giraffes taken as one number nearly 100,000 but when they are considered to be four separate species, the animals would appear to be in more dire need of help and support. The southern giraffe only numbers about 52,000, the reticulated giraffe has a population of about 8,700, the Masai giraffe has about 32,500 individuals and the northern giraffe has a bleak number of only 4,750. Scientists also said that the different species are about as distinct as polar bears and brown bears and because populations are composed of different species, giraffes could not reproduce with one another. "They normally don't hybridize and have fertile offspring in nature," Janke said. Conservationists would have to take into account that the different species do not commonly crossbreed when planning for strategies that aim to help improve the number of the animals. "The remaining former giraffe subspecies cluster genetically into four highly distinct groups, and we suggest that these should be recognized as discrete species," Janke and colleagues wrote in their study. "The conservation implications are obvious, as giraffe population numbers and habitats across Africa continue to dwindle due to human-induced threats." The population of the giraffe has long been declining. The decline in their population is widely blamed on habitat loss, excessive hunting and poaching. The skin of the giraffe is used for clothing items and in some countries like Tanzania, the hunt is driven by beliefs that some parts of the animal can treat HIV infection. "With now four distinct species, the conservation status of each of these can be better defined and in turn added to the IUCN Red List," said Julian Fennessy, from the Giraffe Conservation Foundation in Namibia.
Nubian giraffes are seen in Murchison Falls, Uganda in this undated handout picture. Courtesy Julian Fennessy/Handout via REUTERS WASHINGTON (Reuters) - Genetic research on the world's tallest land animal has found that there are four distinct species of giraffe, not just one as long believed, with two of them at alarmingly low population levels. Scientists on Thursday unveiled a comprehensive genetic analysis of giraffes using DNA from 190 of the towering herbivores from across their range in Africa. The genetic data showed that four separate species of giraffes that do not interbreed in the wild inhabit various parts of the continent. "We were extremely surprised," said conservationist Julian Fennessy, co-director of the Namibia-based Giraffe Conservation Foundation. Beyond genetics, the researchers identified differences among the four species including body shape, coloration and coat patterns. Genetic differences among the four species were comparable to those between polar bears and brown bears, said geneticist Axel Janke of the Senckenberg Biodiversity and Climate Research Centre and Goethe University in Germany. Until now, scientists had recognized a single species, with the scientific name Giraffa camelopardalis. The study identified the four separate species as: the southern giraffe (Giraffa giraffa), with a population of 52,000; the Masai giraffe (Giraffa tippelskirchi), with 32,500; the reticulated giraffe (Giraffa reticulata), with 8,700; and the northern giraffe (Giraffa camelopardalis), with 4,750. "The conservation implications are immense and our findings will hopefully help put giraffe conservation on the map," Fennessy said. The giraffe currently is not listed as endangered, although its population has declined dramatically over the past three decades from more than 150,000 to fewer than 100,000, the researchers said. But the low population levels of the northern giraffe and reticulated giraffe make them some of the world's most endangered large mammals and of high conservation importance, Fennessy said. Giraffes stand up to about 18 feet (5.5 meters) tall, with long necks and legs, a sloped back and two to five short knobs called ossicones atop the head. They have a tan, white or yellowish coat blotched with brownish patches. They roam the savannas of central, eastern and southern Africa, as far north as Chad, south to South Africa, east to Somalia and west to Niger. Fennessy said the biggest threats to the giraffe include habitat destruction due to human population growth as well as poaching for bush meat, their tail hair and "medicinal" parts. Their closest relative is the long-necked African mammal called the okapi. The research was published in the journal Current Biology.
Bercovitch F.B.,Kyoto University |
Deacon F.,Giraffe Conservation Foundation |
Deacon F.,University of the Free State
African Journal of Ecology | Year: 2015
Giraffe are popular animals to watch while on wildlife safaris, and feature prominently in zoos, advertisements, toys and cartoons. Yet, until recently, few field studies have focused on giraffe. We introduce this giraffe topic issue with a review essay that explores five primary questions: How many (sub) species of giraffe exist? What are the dynamics of giraffe herds? How do giraffe communicate? What is the role of sexual selection in giraffe reproduction? How many giraffe reside in Africa? A confluence of causes has produced drastic declines in giraffe population numbers in Africa, and we conclude that guiding giraffe conservation plans depends upon evaluation of the five key quandaries that we pose. © 2015 John Wiley & Sons Ltd. Source