Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
29
result(s) for
"Giraffes - classification"
Sort by:
A comparative approach for species delimitation based on multiple methods of multi-locus DNA sequence analysis: A case study of the genus Giraffa (Mammalia, Cetartiodactyla)
2020
Molecular data are now commonly used in taxonomy for delimiting cryptic species. In the case of giraffes, which were treated as a single species (Giraffa camelopardalis) during half of a century, several molecular studies have suggested a splitting into four to seven species, but the criteria applied for taxonomic delimitation were not fully described. In this study, we have analysed all multi-locus DNA sequences available for giraffes using multispecies coalescent (MSC: *BEAST, BPP and STACEY), population genetic (STRUCTURE, allelic networks, haplotype network and bootstrapping, haplowebs and conspecificity matrix) and phylogenetic (MrBayes, PhyML, SuperTRI) methods to identify the number of species. Our results show that depending on the method chosen, different taxonomic hypotheses, recognizing from two to six species, can be considered for the genus Giraffa. Our results confirm that MSC methods can lead to taxonomic over-splitting, as they delimit geographic structure rather than species. The 3-species hypothesis, which recognizes G. camelopardalis sensu strico A, G. giraffa, and G. tippelskirchi, is highly supported by phylogenetic analyses and also corroborated by most population genetic and MSC analyses. The three species show high levels of nucleotide divergence in both nuclear (0.35-0.51%) and mitochondrial sequences (3-4%), and they are characterised by 7 to 12 exclusive synapomorphies (ES) detected in nine of the 21 nuclear introns analysed for this study. By contrast, other putative species, such as G. peralta, G. reticulata, G. thornicrofti or G. tippelskirchi sensu stricto, do not exhibit any ES in the nuclear genes. A robust mito-nuclear conflict was found for the position and monophyly of G. giraffa and G. tippelskirchi, which is interpreted as the result of a mitochondrial introgression from Masai to southeastern giraffe during the Pleistocene and nuclear gene flow mediated by male dispersal between southern populations (subspecies G. g. giraffa and G. g. angolensis).
Journal Article
Heads up–Four Giraffa species have distinct cranial morphology
2024
Giraffe ( Giraffa spp.) are among the most unique extant mammals in terms of anatomy, phylogeny, and ecology. However, aspects of their evolution, ontogeny, and taxonomy are unresolved, retaining lingering questions that are pivotal for their conservation. We assembled the largest known dataset of Giraffa skulls (n = 515) to investigate patterns of cranial variability using 3D geometric morphometrics. The results show distinct sexual dimorphism and divergent ontogenetic trajectories of skull shape for the north clade ( G . camelopardalis antiquorum , G . c . camelopardalis , G . c . peralta , and G . reticulata ) and the south clade ( G . giraffa angolensis , G . g . giraffa , G . tippelskirchi tippelskirchi , and G . t . thornicrofti ) which was further supported statistically. Discriminant functions found statistically significant cranial shape differences between all four Giraffa species, and in some cases also between subspecies of the same species. Our 3D morphometric analysis shows that the four genetically distinct Giraffa spp. also have distinct cranial morphologies, largely addressable to features of display (ossicones). Our results highlight the importance of focusing future giraffe conservation efforts on each taxon to maintain their unique characteristics and biodiversity in the wild.
Journal Article
A new giraffe ossicone from Wolf Camp, Tunggur Formation, Inner Mongolia suggests a new genus in Bohlinini (Artiodactyla, Giraffidae)
2025
The classic Middle Miocene Wolf Camp locality discovered in 1930 by the Third Asiatic Expeditions of the American Museum of Natural History has been long known to produce an extinct giraffe, Palaeotragus tungurensis Colbert, 1936. Its dental and limb morphology offers tantalizing clues to a close relationship to the living giraffe, Giraffa . Its ossicone, a key part of the giraffe anatomy, is unknown since its initial description. Our discovery, in 2011, of an almost perfectly preserved ossicone from Wolf Camp thus fills this void and is described herein. Novel morphology of the ossicone, unlike any known so far, warrants a new generic name, Qilin , and Q. tungurensis adds important evidence that this Middle Miocene record from Inner Mongolia represents a key taxon in the evolution of the subfamily Giraffinae. Ossicone morphology is fundamentally similar to that of living Giraffa as well as members of Bohlinini. Dentally, Q. tungurensis also strongly supports its membership within Bohlinini with a unique shared derived character of P2-3 para- and metastyles bending inward to mesostyle. Q. tungurensis possesses a slender limb and a modestly deep trough on the posterior surface of the metacarpals that also suggest membership in Bohlinini. Combined with knowledge about its dental and limb morphology, the new Wolf Camp ossicone indicates an important stage of giraffine evolution, and contributes to a better understanding of its chronology and zoogeography.
Journal Article
Comparisons of Schansitherium tafeli with Samotherium boissieri (Giraffidae, Mammalia) from the Late Miocene of Gansu Province, China
2019
We are describing and figuring for the first time skulls of Schansitherium tafeli, which are abundant in the Gansu area of China from the Late Miocene. They were animals about the size of Samotherium with shorter necks that had two pairs of ossicones that merge at the base, which is unlike Samotherium. The anterior ossicones consist of anterior lineations, which may represent growth lines. They were likely mixed feeders similar to Samotherium. Schansitherium is tentatively placed in a very close position to Samotherium. Samotherium and Schansitherium represent a pair of morphologically very similar species that likely coexisted similarly to pairs of modern species, where the main difference is in the ossicones. Pairs of ruminants in Africa, for example, exist today that differ mostly in their horn shape but otherwise are similar in size, shape, and diet. The absence of Schansitherium from Europe is interesting, however, as Samotherium is found in both locations. While is it challenging to interpret neck length and ossicone shape in terms of function in combat, we offer our hypothesis as to how the two species differed in their fighting techniques.
Journal Article
Astragalar Morphology of Selected Giraffidae
2016
The artiodactyl astragalus has been modified to exhibit two trochleae, creating a double pullied structure allowing for significant dorso-plantar motion, and limited mediolateral motion. The astragalus structure is partly influenced by environmental substrates, and correspondingly, morphometric studies can yield paleohabitat information. The present study establishes terminology and describes detailed morphological features on giraffid astragali. Each giraffid astragalus exhibits a unique combination of anatomical characteristics. The giraffid astragalar morphologies reinforce previously established phylogenetic relationships. We find that the enlargement of the navicular head is a feature shared by all giraffids, and that the primitive giraffids possess exceptionally tall astragalar heads in relation to the total astragalar height. The sivatheres and the okapi share a reduced notch on the lateral edge of the astragalus. We find that Samotherium is more primitive in astragalar morphologies than Palaeotragus, which is reinforced by tooth characteristics and ossicone position. Diagnostic anatomical characters on the astragalus allow for giraffid species identifications and a better understanding of Giraffidae.
Journal Article
DNA reveals that giraffes are four species — not one
2016
Finding could alter conservation strategies for long-necked animals.
Journal Article
Behaviour Classification on Giraffes (Giraffa camelopardalis) Using Machine Learning Algorithms on Triaxial Acceleration Data of Two Commonly Used GPS Devices and Its Possible Application for Their Management and Conservation
by
Berger, Anne
,
Brandes, Stefanie
,
Sicks, Florian
in
behavior classification
,
giraffe
,
giraffe conservation
2021
Averting today’s loss of biodiversity and ecosystem services can be achieved through conservation efforts, especially of keystone species. Giraffes (Giraffa camelopardalis) play an important role in sustaining Africa’s ecosystems, but are ‘vulnerable’ according to the IUCN Red List since 2016. Monitoring an animal’s behavior in the wild helps to develop and assess their conservation management. One mechanism for remote tracking of wildlife behavior is to attach accelerometers to animals to record their body movement. We tested two different commercially available high-resolution accelerometers, e-obs and Africa Wildlife Tracking (AWT), attached to the top of the heads of three captive giraffes and analyzed the accuracy of automatic behavior classifications, focused on the Random Forests algorithm. For both accelerometers, behaviors of lower variety in head and neck movements could be better predicted (i.e., feeding above eye level, mean prediction accuracy e-obs/AWT: 97.6%/99.7%; drinking: 96.7%/97.0%) than those with a higher variety of body postures (such as standing: 90.7–91.0%/75.2–76.7%; rumination: 89.6–91.6%/53.5–86.5%). Nonetheless both devices come with limitations and especially the AWT needs technological adaptations before applying it on animals in the wild. Nevertheless, looking at the prediction results, both are promising accelerometers for behavioral classification of giraffes. Therefore, these devices when applied to free-ranging animals, in combination with GPS tracking, can contribute greatly to the conservation of giraffes.
Journal Article
Genomic analysis reveals limited hybridization among three giraffe species in Kenya
by
Mijele, Domnic
,
Janke, Axel
,
Stacy-Dawes, Jenna
in
Analysis
,
Bats
,
Biomedical and Life Sciences
2023
Background
In the speciation continuum, the strength of reproductive isolation varies, and species boundaries are blurred by gene flow. Interbreeding among giraffe (
Giraffa
spp.) in captivity is known, and anecdotal reports of natural hybrids exist. In Kenya, Nubian (
G. camelopardalis camelopardalis
), reticulated (
G. reticulata
), and Masai giraffe sensu stricto (
G. tippelskirchi tippelskirchi
) are parapatric, and thus, the country might be a melting pot for these taxa. We analyzed 128 genomes of wild giraffe, 113 newly sequenced, representing these three taxa.
Results
We found varying levels of Nubian ancestry in 13 reticulated giraffe sampled across the Laikipia Plateau most likely reflecting historical gene flow between these two lineages. Although comparatively weaker signs of ancestral gene flow and potential mitochondrial introgression from reticulated into Masai giraffe were also detected, estimated admixture levels between these two lineages are minimal. Importantly, contemporary gene flow between East African giraffe lineages was not statistically significant. Effective population sizes have declined since the Late Pleistocene, more severely for Nubian and reticulated giraffe.
Conclusions
Despite historically hybridizing, these three giraffe lineages have maintained their overall genomic integrity suggesting effective reproductive isolation, consistent with the previous classification of giraffe into four species.
Journal Article
The Faecal Microbiome Analysed from Healthy, Free-Roaming Giraffes (Giraffa camelopardalis)
2025
Similar to other herbivores, healthy giraffes (
Giraffa camelopardalis
) rely on a variety of symbiotic microorganisms in their digestive systems to break down cellulose and hemicellulose. In this study, we investigate the impact that external stimuli might have on the faecal prokaryote composition of healthy, free-roaming giraffes. Faecal samples were collected from six male and seven female giraffe individuals, over a 2-year period, during the wet and dry seasons, from six locations within the Free State Province, South Africa. Giraffe populations were exposed to one of two feeding practices which included provision of supplemental feed or only naturally available vegetation. Seventeen (17) different prokaryotic phyla, consisting of 8370 amplicon sequence variants (ASVs), were identified from the 13 healthy, adult, free-roaming giraffes included in the study. Overall, the bacterial phyla with the largest relative abundance included Fusobacteria (22%), followed by Lentisphaera (17%) and Cyanobacteria (16%), which included 21 dominant prokaryotic ASVs. The relative abundance of Ruminococcaceae UCG 014 and
Treponema 2
were found to be significantly (
P
< 0.05) higher and
Escherichia
/
Shigella
,
Romboutsia
and
Ruminococcus 1
significantly lower for giraffes receiving supplemental feed compared to natural available vegetation. This is the first study to investigate the composition of the faecal prokaryotic communities of healthy, free-roaming giraffes. The analysis of faecal prokaryotes contributes to the development of non-invasive methods for assessing the nutritional status and identifying health issues in giraffe populations. Ultimately, such advances are beneficial towards the larger-scale conservation, determining nutritional needs and management of other sensitive wildlife species, as well.
Journal Article
Analysis of the Microbial Diversity in the Fecal Material of Giraffes
2018
Using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequencing, the microbiota of the fecal material of seven giraffes living in captivity at the Jacksonville Zoo and Gardens, Jacksonville, FL was investigated. In all samples, the most predominant bacterial phylum was the Firmicutes followed by Bacteroidetes. The most predominant fungi were members of the phylum Ascomycota followed by Neocallimastigomycota in five of seven samples. The reverse was true in the other two samples.
Journal Article