Giraffe speciation and conservation - two newly published papers
Two interesting pieces of work have been published Early Online with the African Journal of Ecology. The first is an in-depth analysis of the Namibian giraffe populations being genetically distinct from its previously assumed family in South Africa, whilst the other paper looks at the decline of the Rothschild's giraffe in Lake Nakuru NP.
Genetic structure of two populations of the Namibian giraffe, Giraffa camelopardalis angolensis
Rick Brenneman, Edward E. Louis, Jr & Julian Fennessy
Abstract
Two geographically distinct populations of giraffe (Giraffa camelopardalis) were sampled for this study, the northern Namib Desert and Etosha National Park. Population genetic
parameters and relationships within subpopulations were estimated to better understand the genetic architecture of this isolated subspecies. Gene flow between the geographically separated populations can be attributed to recent translocation of giraffe between the two populations. Inbreeding estimates in the six subpopulations studied were low though we found evidence that genetic drift may be affecting the genetic diversity of the isolated
populations in northern Namibia. Population dynamics of the sampling locations was inferred with relationship coefficient analyses. Recent molecular systematics of the Namibian giraffe populations indicates that they are distinct from the subspecies Giraffa camelopardalis
giraffa and classified as G. c. angolensis. Based on genetic analyses, these giraffe populations of northern Namibia, the desert-dwelling giraffe and those protected in Etosha
National Park, are a distinct subspecies from that previously assumed; thus we add data on G. c. angolensis to our scientific knowledge of this giraffe of southern Africa.
www3.interscience.wiley.com/journal/122585277/abstract
Implications of closed ecosystem conservation management: the decline of Rothschild’s giraffe (Giraffa camelopardalis rothschildi) in Lake Nakuru National Park, Kenya
Rick A. Brenneman, Richard K. Bagine, David M. Brown, Robert Ndetei & Edward E. Louis Jr
Abstract
Giraffe were historically free-ranging across most of sub-Saharan Africa but are now most often confined to national parks, conservation areas, or private ranches. Five viable populations of Rothschild’s giraffe (Giraffa camelopardalis rothschildi) remain in protected areas in Kenya and Uganda. The viable population in Uganda is Murchison Falls National
Park and the four populations in Kenya are Lake Nakuru National Park (LNNP), Ruma National Park, Giraffe Manor, and Mwea Natural Reserve. The Kenya Wildlife Service queried a rapid decline in LNNP giraffe numbers falling from 153 individuals (1995) to 62 individuals (2002) and the failure of that population to recruit young in those years. Significantly reduced browse options, inbreeding depression and preferential lion predation were considered as potential reasons for this trend. Population genetic parameter estimates derived from multilocus genotype analyses suggest that the LNNP population was in good genetic health with respect to the likelihood of inbreeding depression. The population decline coincided with the drought attributed to the 1994 El Nino. Possible dietary complications from highly
concentrated tannin levels because of forced over consumption of the park’s declining acacia trees may have compromised young giraffe, making them easy and opportunistic prey for the park’s lion population.