Population assessment and conservation status of African lions (Panthera leo)

Abstract

For several decades, the lion (Panthera leo) has undergone significant population decline across its range. The aim of this dissertation was to critically assess the current conservation status of Africa’s most iconic carnivore. This included determining methods used to survey them, the conservation status of the global population, how fragile lion subpopulations are, and the perceived threats to the species across their African range. As with most carnivores, several survey methods have been developed to estimate lion population abundance. To assess the current state of lion survey methodologies, I conducted a systematic literature review of peer reviewed scientific publications. The strengths and weaknesses of each method were considered, as well as their reliability and applicability in determining abundance and distribution. Building on from how lions are surveyed, I used current data that are available to assess the current population and distribution of lions to produce the updated IUCN Red List Assessment (RLA). RLAs provide a standardised and comprehensive tool to evaluate the status of species, prioritise conservation efforts, and drive informed decision-making at the global, national, and local levels. Extant lion range was estimated to be ~1,571,296 km² - an estimated 36 % range decline since 2002 (three lion generations). Based on this significant decline in range, which is synonymous with a decline in population size and abundance, a 36 % decline in population numbers for the lions was suspected. Therefore, the species met the requirements for a Vulnerable listing (Red List criteria A2abcd). As effective species conservation is about more than just understanding how many there are, I, in collaboration with other experts in large carnivore conservation, examined the socio-political and ecological fragility (hereafter fragility: defined as a species vulnerability to extinction) of known lion populations. By combining ecological and socio-political metrics, an overall fragility index demonstrated which lion populations were more vulnerable to extinction. The analysis revealed several populations were highly fragile and lion populations in Somalia were the most fragile while those in Botswana are the least. Populations that had the highest fragility included Bush-Bush (Somalia) and Maze National Park (Ethiopia). As the RLA indicated that populations are declining, I sought to determine the severity of the existing anthropogenic threats to lions driving these declines. To do this, I conducted an online questionnaire of experts across lion range. A threat severity index was developed for each subpopulation, and I assessed how this varied between subpopulations and across regions. A resource availability index was also developed to identify lion subpopulations which are not sufficiently resourced (e.g., funding, anti-poaching equipment, vehicles). This allowed me to highlight populations that are perceived as highly threatened and that are under-equipped. I found the total threat index differed significantly among regions, being highest (i.e. most severe) in Central Africa and lowest (i.e. least severe) in southern Africa. Perceived resource availability was highest in Rwanda, Chad and Benin and lowest in six countries including Angola, Burkina Faso, Niger, South Sudan, Sudan and Uganda. This analysis identified how specific threats differ between regions. I offer valuable insights into the species' status and provide innovative recommendations that could enhance the management of lions across their range. This includes conservation interventions that target specific threats while incorporating socio-political and ecological factors which contribute to a population’s fragility. As lions remain listed as Vulnerable, and lion populations continue to decline, I recommend that the regional strategies be updated based on improved data and information available. To ensure that population data gathered and reliable and robust, harmonised survey methods need to be developed and implemented across the species range, especially in areas where survey data are poor or lacking. In a world where we are losing species at an unprecedented rate, effective and targeted conservation is needed, that is guided by the best available data, to ensure that the lion isn’t one of those species that disappears.