Population dynamics of the Maasai giraffe (Giraffa camelopardalis tippelskirchi) in Tarangire-Manyara Ecosystem
Demographic studies can show overall population performance, help understand population structure and recognize animal distribution and movement. In order to investigate the social structure of giraffes in the Tarangire-Manyara Ecosystem, data on population structure, sex ratios, age ratios and habitat preference were examined in three protected areas. These areas included Lake Manyara National Park, Manyara […]
Ramifying effects of the risk of predation on African multi-predator, multiprey large-mammal assemblages and the conservation implications
Impacts of predators on prey populations are incurred not only through mortality inflicted, but also from how the risk of mortality affects the behaviour, spatial distribution and resource access of potential prey species. This risk is governed by exposure to predators and vulnerability following encounters. Behavioural responses to reduce risks have ramifying consequences for habitat […]
All the eggs in one basket: A countrywide assessment of current and historical giraffe population distribution in Uganda
To design effective conservation and management strategies at the national scale, it is important to consider population trends across space and time. Here we assessed the near threatened Rothschild’s giraffe (Giraffa camelopardalis rothschildi) in Uganda. We applied individual-based photographic surveys to generate abundance estimates for all extant populations, using either mark-recapture estimates or complete enumeration, […]
Movements and source–sink dynamics of a Masai giraffe metapopulation
Spatial variation in habitat quality and anthropogenic factors, as well as social structure, can lead to spatially structured populations of animals. Demographic approaches can be used to improve our understanding of the dynamics of spatially structured populations and help identify subpopulations critical for the long-term persistence of regional metapopulations. We provide a regional metapopulation analysis […]
Spatial variation in giraffe demography: a test of 2 paradigms
Examination of spatial variation in demography among or within populations of the same species is a topic of growing interest in ecology. We examined whether spatial variation in demography of a tropical megaherbivore followed the “temporal paradigm” or the “adult survival paradigm” of ungulate population dynamics formulated from temperate-zone studies. We quantified spatial variation in […]
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 […]
Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates
Studies that focus on single predator–prey interactions can be inadequate for understanding antipredator responses in multi-predator systems. Yet there is still a general lack of information about the strategies of prey to minimize predation risk from multiple predators at the landscape level. Here we examined the distribution of seven African ungulate species in the fenced […]
Modeling the dynamics of migrations for large herbivore populations in the Amboseli National Park, Kenya
The spread of human activity, settlement and land fragmentation threatens the migrations of large migratory ungulates in Africa. Modelling the migrations gives conservationists a tool for building scenarios of the threats and containment options. We propose a simple spatially explicit mathematical model of ungulate migrations based on the seasonal distribution of vegetation quantity and quality […]