Scene From Above: Retinal Ganglion Cell Topography and Spatial Resolving Power in the Giraffe (Giraffa camelopardalis)
The giraffe (Giraffa camelopardalis) is a browser that uses its extensible tongue to selectively collect leaves during foraging. As the tallest extant terrestrial mammal, its elevated head height provides panoramic surveillance of the environment. These aspects of the giraffe’s ecology and phenotype suggest that vision is of prime importance. Using Nissl-stained retinal wholemounts and stereological […]
Physiological cross-sectional area of the masticatory muscles in the giraffe (Giraffa camelopardalis)
Numerous studies have investigated how the skeletal morphology is related to feeding behaviour (Christiansen and Adolfssen 2005; Wroe et al. 2005; Christiansen and Wroe 2007; Ellis et al. 2009; Koyabu and Endo 2009; Koyabu et al. 2009; Koyabu and Endo 2010), although remarkably few studies have focused on the architecture of masticatory muscles from which […]
Are giraffes pollinators or flower predators of Acacia nigrescens in Kruger National Park, South Africa?
We examined the relationship between giraffes (Giraffa camelopardalis) and Acacia nigrescens in Kruger National Park, South Africa, to determine whether these tall ungulates may be providing a pollination service for the trees, or are simply flower predators. We quantified florivory and subsequent fruit set in the presence and absence of giraffes. Acacia nigrescens flowers are […]
The feeding behaviour of giraffe in Niger
The remaining West African giraffes (Giraffa camelopardalis) are found in Niger (62 individuals in January 1998). Their feeding behaviour was studied by direct observation during two periods of 6 and 12 mo. The giraffe’s diet is diverse: at least 45 plant species were eaten, depending on spatial arrangement and a given plant’s stage of growth. […]
Social influences on vigilance behaviour in giraffes, Giraffa camelopardalis
Vigilance in ungulates is considered to have a predominantly antipredator function, with the frequency and duration of scans per individual decreasing with increasing group size. Social influences on vigilance scans have been overlooked in studies on ungulates, although studies in primates and birds show that conspecific scans are important determinants of vigilance behaviour. We investigated […]
Grazing behaviour of the giraffe in Hwange National Park, Zimbabwe
The giraffe (Giraffa camelopardalis) is usually described as an exclusive browser, feeding only on shrubs and trees, preferably between 2 and 5 m above ground (Lamprey, 1963; McNaughton & Georgiadis, 1986; Ciofolo & Le Pendu, 2002). Although browsing seems to be an easier form of feeding for giraffes in terms of accessibility and vigilance (Young […]
Fecal steroid analysis of female giraffe (Giraffa camelopardalis) reproductive condition and the impact of endocrine status on daily time budgets
Gestation and lactation can impose substantial energetic costs on female mammals. We developed a non-invasive means to determine reproductive condition in female giraffe using fecal steroid analysis. Giraffe may be especially challenged during their reproductive cycle because of two characteristics: they are impregnated while lactating and they do not breed seasonally. We studied the social […]
The feeding ecology of a selective browser, the giraffe (Giraffa camelopardalis tippelskirchi)
A herbivore can manipulate certain factors of its feeding behavior in order to achieve the metabolic requirements for reproduction. These factors include choice of habitat in which to feed, the selection criteria for choosing food items, and the time allocated to feeding or devoted to other energy-consuming activities. The manipulation of these behavioural factors by […]