Examining disease prevalence for species of conservation concern using non-invasive spatial capture–recapture techniques
on‐invasive techniques have long been used to estimate wildlife population abundance and density. However, recent technological breakthroughs have facilitated non‐invasive estimation of the proportion of animal populations with certain diseases. Giraffes Giraffa camelopardalis are increasingly becoming recognized as a species of conservation concern with decreasing population trajectories across their range in Africa. Diseases may be an […]
Proximity to humans affects local social structure in a giraffe metapopulation
Experimental laboratory evidence suggests that animals with disrupted social systems express weakened relationship strengths and have more exclusive social associations, and that these changes have functional consequences. A key question is whether anthropogenic pressures have a similar impact on the social structure of wild animal communities. We addressed this question by constructing a social network […]
Revisiting giraffe photo-identification using deep learning and network analysis
An increasing number of research programs rely on photographic capture-recapture (vs. direct marking) of individuals to study distribution and demography within animal populations. Photo-identification of individuals living in the wild is sometimes feasible using idiosyncratic coat or skin patterns, like for giraffes. When performed manually, the task is tedious and becomes almost impossible as populations […]
An automated program to find animals and crop photographs for individual recognition
Detailed data on individual animals are critical to ecological and evolutionary studies, but attaching identifying marks can alter individual fates and behavior leading to biases in parameter estimates and ethical issues. Individual-recognition software has been developed to assist in identifying many species from non-invasive photographic data. These programs utilize algorithms to find unique individual characteristics […]
Season of birth affects juvenile survival of giraffe
Variation in timing of reproduction and subsequent juvenile survival often plays an important role in population dynamics of temperate and boreal ungulates. Tropical ungulates often give birth year round, but survival effects of birth season for tropical ungulate species are unknown. We used a population of giraffe in the Tarangire Ecosystem of northern Tanzania, East […]
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, […]
Precision, accuracy, and costs of survey methods for giraffe Giraffa camelopardalis
Giraffes Giraffa camelopardalis are megafaunal browsers and keystone species in African savanna ecosystems. Range-wide population declines are suspected, but robust data are lacking. Tanzania holds the largest population of giraffe of any range state, and aerial surveys constitute most of Tanzania’s giraffe population monitoring data, but their accuracy has not yet been assessed. An IUCN […]
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 […]
Higher than expected growth rate of the Endangered West African giraffe Giraffa camelopardalis peralta: a successful human–wildlife cohabitation
The West African giraffe is a genetically unique population represented only by the subspecies Giraffa camelopardalis peralta, categorized as Endangered on the IUCN Red List. These giraffes live outside protected areas, without natural predators and share their habitat with local people and their livestock. This study provides demographic data on this poorly studied megaherbivore and […]