Reproductive failure in female Thornicroft’s giraffe (Giraffa camelopardalis thornicrofti) in Zambia
Reproductive suppression is common among mammals residing in cooperative social systems and is characterized by the cessation of ovulation in subordinate females until their social environment releases them from a temporary freeze on ovulating (e.g., dwarf mongoose, Helogale parvula (Creel, Creel, Wildt, & Monfort, 1992); African wild dogs, Lycaon pictus (Creel, Creel, Mills, & Monfort, […]
Conservation conundrum: Endangered predators eating endangered prey
As populations of wildlife dwindle in number, and as ecosystems suitable for animals disappear, conservation conundrums emerge that have no easy solutions. One such issue involves predators and prey. What can be done when an endangered species of predators might be hastening the extinction of an endangered species of prey by including it in their […]
Social and demographic influences on the feeding ecology of giraffe in the Luangwa Valley, Zambia: 1973–2014
Body size influences metabolic rate, which impacts feeding ecology. Body mass differs by sex in size-dimorphic species, such as giraffes, and also by age. Giraffes reside in a fission–fusion social system, which influences feeding ecology due to frequent changes in group size and composition. We analysed 40 years of feeding records collected from a population […]
Regional Differences in Seasonal Timing of Rainfall Discriminate between Genetically Distinct East African Giraffe Taxa
Masai (Giraffa tippelskirchi), Reticulated (G. reticulata) and Rothschild’s (G. camelopardalis) giraffe lineages in East Africa are morphologically and genetically distinct, yet in Kenya their ranges abut. This raises the question of how divergence is maintained among populations of a large mammal capable of long-distance travel, and which readily hybridize in zoos. Here we test four […]
A Tall Order: Hormones and Behavior in Giraffes
Hormones are chemical messengers produced by specific organs in the body that travel in the blood to target tissues and influence behavior and physiology. The major hormone of interest to us is progesterone, a steroid hormone produced by the ovary and placenta in females. The body is constantly churning out new hormones, while destroying the […]
Observations on puberty and pregnancy in female giraffe (giraffa camelopardalis)
The age at sexual maturity in the female giraffe G. camelopardalis was found to be 3 years 10 months when in captivity and 4 years 8 months in wild animals. The mean calving interval was 19.9 months for wild animals, and 21.5 months for captives. Post partum intervals as short as 19, 23 and 27 […]
Fecal Progestagen and Estrone During Pregnancy in a Giraffe: A Case Report
The present study was carried out to measure fecal progestagen and estrone concentrations during pregnancy in a giraffe and examine the possibility of utilizing this assay system for pregnancy diagnosis. Fecal samples were collected from a giraffe during her third and fourth parities and mixed with methanol to prepare a fecal solution. Diluted fecal solution […]
Maternal Investment in Captive Giraffes
Sex-biased maternal investment involves differential allocation of resources to production and rearing of sons or daughters as a function of their anticipated reproductive output. We examined reproductive investment among captive giraffe, (Giraffa camelopardalis) over a 21-year period to determine extent to which female invest differentially in offspring by sex. We found an unbiased sex ratio […]
Reproductive life history of Thornicroft’s giraffe in Zambia
Knowledge of the reproductive life history of giraffe in the wild is sparse. Giraffe have two fairly unusual reproductive patterns among large mammals: they can become pregnant while lactating, and calf mortality is extremely high. Longitudinal records are largely absent, so tracking reproductive parameters tends to combine information from captive and field studies. In this […]
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 […]