Estimation of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park using a capture–recapture survey (original) (raw)
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Estimating African Lion Abundance in the Southwestern Kgalagadi Transfrontier Park
African Journal of Wildlife Research, 2017
African lions (Panthera leo) are threatened across their natural range. However, the Kgalagadi Transfrontier Park (KTP) is a stronghold for the species. A population assessment in 2010 observed a skew in the sex structure with a greater proportion of males (56%) which raised concerns about the long-term sustainability of the greater KTP lion population. A key indicator of how a population responds to changes in population structure is population size. We conducted an intensive lion census between 2013 and 2015 in the southwestern KTP (14 250 km 2) driving 49 784 km over 317 sampling days, which resulted in 1162 lion sightings. Registering the population through individual identification (n = 261) provided a benchmark against which other techniques could be measured and for a non-invasive marking technique. Open-population mark-recapture provided the most precise estimate of population size (n = 246; 95%CI: 237-256). Track indices (n = 242; 95%CI: 176-307) provided a similar best estimate, but were imprecise. Minimum-known-alive calculations (n = 145) provided a gross underestimate. All the methods used in this study indicate a larger lion population size than previous estimates.
Estimates of Density and Population Size of African Lions in the Katavi National Park, Tanzania
Open Journal of Ecology, 2022
Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but there is currently limited reliable data indicating density and population size. This hinders the development of conservation action plans, including population monitoring, for this species. To address this data gap, we assessed lions' demography and population estimates (population size and density) in the Katavi National Park using a call-back survey method. In addition, we assessed ecological factors that influenced distribution of lions to the call-back stations. Our estimated population size revealed 84 lions (95% CI 53-116), with a density of 5/100 km 2 (95% CI 3.14-6.86) in the sampled area, representing 38% of the total park. This resulted in an estimated 214 individuals when extrapolated to the whole park. Sixty-seven percent of lions that responded to the stations were female, and ecological factors that significantly influenced their distribution included elevation, land cover, precipitation, temperature, wind speed, and prey abundance. Our results suggest that female lions are more abundant than males in Katavi National Park and that population size and density estimates, as well as understanding prey-lion relations, are important indices for lion monitoring and identifying conservation priorities. Further, our study suggests that the call-back survey method is an effective, rapid, and less costly population assessment method for lions, may be useful for assessing other social species in the Katavi ecosystem and can be a useful tool for community engagement and contributing to scientific monitoring.
Lion status updates from five range countries in West and Central Africa
The lion Panthera leo is listed as Vulnerable on the IUCN Red List of Threatened Species and the species' current status raises increasing concern among lion specialists across its African range. The situation is particularly alarming in West and Central Africa, where as few as 1000-2850 lions might remain, and where it is considered regionally Endangered in West Africa. Here we present results from lion surveys conducted in 2006-2010, covering 12 Lion Conservation Units (LCUs) in West Africa and three LCUs in Central Africa. We were able to confirm lion presence in only two of the LCUs surveyed in West Africa, and in none of the LCUs surveyed in Central Africa. Our results raise the possibility that no resident lion populations exist in Congo, Côte d'Ivoire and Ghana.
Lion populations in West and Central Africa are small and fragmented. In areas where park management is weak, threats will likely facilitate the extinction of the lion. Wildlife management requires knowledge of the population estimate. The population of lions in Waza National Park (Waza NP) was assessed by individual identification of members in the population. The population was assessed to comprise of 14-21 adult individual lions. The age structure was skewed towards adults; cubs comprised 22% of all lions identified while the sex ratio was 1 : 3. Two out of four collared lions were lost to illegal, retaliatory killings within 1 year; and probably two more males and one more female were also killed during this period. The lion population appears to have declined during the last 5 years with six lions dying per year, which is at a much higher rate than observed in the previous decades. Human-livestock pressure has increased tremendously in this period, resulting to frequent human-lion conflicts. To ensure the survival of the lion in Waza NP and in the entire region, management needs to intensify efforts to mitigate the pressure from humans and their livestock.
African Lion Population Estimates in Tanzania’s Ruaha National Park
Open Journal of Ecology, 2022
Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston's (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km 2 revealed 286 lions (95% CI, 236-335) during the wet season, and 196 lions (95% CI, 192-200) during the dry season. The density of lions was 9.1/100 km 2 during the wet season, and 6.3/100 km 2 during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on How to cite this paper:
Oryx, 2009
A d r i a n T r e v e s , A n d r e w J . P l u m p t r e , L u k e T . B . H u n t e r and J o e l Z i w a Abstract Conservationists are raising concerns over high lion Panthera leo mortality and prey population declines in the area at the frontier between the Democratic Republic of Congo and Uganda. Confirming if threats to lions are severe or lion populations are disappearing requires extensive surveys on the ground because aerial detection of lions is inaccurate. Yet, ground surveys over large areas are unsafe or infeasible in the war-torn study area. We used aerial surveys of medium-to large-bodied ungulate prey to estimate lion abundance in two adjoining parks: Queen Elizabeth National Park, Uganda, and Parc National des Virunga, Democratic Republic of Congo. We validated two approaches to predict lion abundance using total counts of lions from Uganda. From this, we predict the two national parks together could have held 221 lions in 2004 and they have the potential to hold 905 lions if prey recover and lion-specific mortality is curbed. This makes the region a potential stronghold for the species in central Africa. However, a recent one third decline in lion numbers in the Ugandan Park and pervasive threats to the Congolese Park lead us to recommend immediate conservation intervention for lions and their prey. In Uganda, we recommend focused action to protect lions from poaching and retaliation, whereas in Congo, general enforcement of wildlife protection and a ground-based survey for lions are needed.
J. ROUX, S. VAN DER MERWE, E. MALAN, M.W. VAN ROOYEN & M.J. WINGFIELD. South African native trees increasingly threatened by diseases. South African Journal of Botany, Volume 76, Issue 2, April 2010, Pages 402–403.
The number of free ranging African lions lations are small and fragmented in West and Central Africa, whereas the species still occurs widely in East Panthera leo has never been comprehensively assessed. We present an inventory of available information, cover-and Southern Africa. The results concur with the current IUCN Red List categorization of the lion as Vulnerable. ing most protected areas and ranging in quality from educated guesses to individually known populations. This gives a conservative estimate of 16,500-30,000 free of these methods. Spoor counts are included in this category, but the methodology has to be further developed
Methods for lion monitoring: a comparison from the Selous Game Reserve, Tanzania
African Journal of Ecology, 2012
The Selous Game Reserve in Tanzania is believed to contain Africa's largest population of lions (Panthera leo), making it a popular destination for trophy hunters and photographic tourists. However, a lack of recent data has raised concerns about the conservation status of this iconic population, so we collected two types of population data between 2006 and 2009. First, we identified 112 individual animals in an 800 km 2 study area in the photographic tourism part of Selous, giving a density of 0.14 individuals km À2. This density estimate was similar to results using the same method from 1997 to 1999, but the adult sex ratio has decreased from 1 male : 1.3 female in 1997 to 1 male : 3 females in 2009. Second, using buffalo calf distress calls, we conducted call-up surveys to census lions in three hunting sectors in the west, east and south of Selous and in the northern photographic area. Estimated adult lion densities varied from 0.02 to 0.10 km À2 , allowing an overall population estimate of 4,300 (range: 1,700-6,900). Our results highlight the value of call-ups in surveying cryptic hunted carnivores but stress the importance of long-term projects for calibrating the responses to call-ups and for measuring trends in demography and population size.
Managers of reintroduced lion (Panthera leo) populations in small reserves (<1000 km 2 ) in South Africa are challenged by high rates of population increase and how best to control them. We combined data from 14 small, fenced reserves to evaluate growth rate parameters and compared them to those in larger and/or open reserves. Growth rates of lions in small fenced reserves were only matched by those in Nairobi National Park (NP), which is relatively small and where the majority of the subadults emigrated away from the park. Initially, South African managers unconsciously mimicked this system by removing subadults to control population numbers, but increasingly chose euthanasia and hunting in the past decade, as the demand for wild lions for translocation decreased. They have, however, expressed a desire to use other methods of population control and mimic other open systems such as Kruger NP and Serengeti NP. Kruger NP had older ages of first reproduction and longer inter-birth intervals that could be mimicked through selective contraception. Alternatively, Serengeti NP had smaller litter sizes and lower cub survival, which could be mimicked through surgery to reduce litter sizes and, less attractively as it still involves lethal management and raises serious ethical concerns, selective culling of cubs. Mimicking Kruger NP may be more desirable as it is more ecologically similar to the small reserves than Serengeti NP. This understanding of the current situation, and how it could be altered to more closely mimic natural systems, will facilitate the development of a metapopulation-based management plan for lions in small reserves in South Africa.