Lion Density Research Articles

An empirical and experimental test of risk and costs of kleptoparasitism for African wild dogs (Lycaon pictus) inside and outside a protected area

The energetic output of hunting African wild dogs (Lycaon pictus) is extremely high. Therefore, survival and reproductive success depend not only on the ability to secure prey but also on minimizing foraging costs. African wild dogs often coexist with lions (Panthera leo) and spotted hyenas (Crocuta crocuta); these competitors can seriously increase foraging costs by kleptoparasitism. In this study, we empirically and experimentally assessed the risk and costs of kleptoparasitism for African wild dogs inside Hwange National Park, where hyena densities are high, and outside the park, where hyena densities are lower. Lion densities within the study area have been fluctuating. The risk and costs of kleptoparasitism were determined by comparing direct observations during hunt follows of radio collared African wild dog packs and by the use of experimental call-ups with African wild dog sounds inside and outside Hwange National Park. The risk of kleptoparasitism was found to be significantly higher inside the park. The time it took lions and hyenas to get to the kill site during African wild dog hunts was longer outside the park allowing the dogs a longer carcass access time. The found differences in risk and costs of kleptoparasitism could contribute to African wild dog habitat choice for the buffer zone outside Hwange National Park. As habitat choice in and around protected areas is often related to the possibility of exposure to an edge effect, interspecific competition should be considered in the conservation strategy of African wild dogs. Copyright 2011, Oxford University Press.

Inbreeding and density‐dependent population growth in a small, isolated lion population

AbstractIn South Africa, more than 30 small, enclosed game reserves have reintroduced lions over the last two decades, which now house more than 500 individuals. There is a high risk of inbreeding in these fragmented, fenced and isolated populations, which may be compounded by a lack of management guidelines. A population of 11 founder lions Panthera leo was reintroduced to Madikwe Game Reserve in 1995, and this population has in turn become a source for reestablishing other populations. Only four lineages were reintroduced, founder males were related to founder females, and since 1997, only one male lineage maintained tenure for >9 years, resulting in breeding with direct relatives. Interventionist management to limit lion population growth and inbreeding in Madikwe has taken the form of translocating, trophy hunting and culling of mainly sub adult lions. Despite this management, inbreeding started 5 years after reintroduction. Reproductive performance and thus population growth in Madikwe were dependent on the overall lion population density. When lion density was low, females first gave birth at a significantly younger age and produced larger litters, resulting in a high population growth rate, which decreased significantly when lion density in the park reached carrying capacity, that is, 61 lions. This might have profound consequences for future reestablishment of lion populations when restocking new reserves: our study illustrates the need for founder populations of reintroduced endangered predator species to be as large and genetically diverse as possible, and thereafter new genetic material should be supplemented. The development of such management guidelines is becoming very important as large predator populations become increasingly fragmented and managed as metapopulations.

Climate and landscape correlates of African lion (Panthera leo) demography

AbstractAlthough many studies have documented aspects of lion ecology, they have generally focused on single sites, leaving broader‐scaled factors unanalysed. We assessed range‐wide effects of eight biotic and 26 abiotic variables on lion distribution and ecology, based on data compiled from published sources on lion population ecology in 27 protected areas in Africa. Lion pride size and composition were independent of lion density; lion density and home range size were inversely related; and lion density was positively related to rainfall, soil nutrients and annual mean temperature, with some interactive effects between rainfall and soil nutrients. Lion demography was associated most strongly with rainfall, temperature and landscape features. Herbivore biomass and lion density were correlated in univariate regression analyses. However, because herbivore biomass was also related to rainfall and temperature, hierarchical partitioning (HP) allowed us to evaluate independent effects of each variable on lion demography revealing that herbivore biomass had negligible independent contributions. HP indicated that climatic parameters explained 62% of overall variance in demographic parameters, whereas landscape features explained only 32%; climatic parameters were fairly balanced between effects of temperature (34%) and rainfall (28%). Prey (herbivore) biomass is important for lion survival, but its effects appear secondary to environmental factors.

Demographic structure and abundance of Asiatic lionsPanthera leo persicain Girnar Wildlife Sanctuary, Gujarat, India

AbstractAsiatic lionsPanthera leo persica, once confined to the 1,883 km2Gir Protected Area in Gujarat, India, have in the past 2 decades colonized the adjacent Girnar forest, coastal scrub and agro-pastoral areas covering c. 10,000 km2. In May 2008 the Government of Gujarat declared 180 km2of the sacred Girnar forests a Wildlife Sanctuary. We obtained data on location, age, gender and group composition of lions in Girnar Wildlife Sanctuary from opportunistic sightings during March–May 2008 and from systematic surveys in April 2008 (six surveys of 3–4 days each), totalling 81 lions on 40 occasions. Of the 81 sightings 43% were in the recruitment age group. Adult sex ratio was 0.87 males : 1 female. In the systematic survey we made 26 sightings of nine individuals, identified from their vibrissae patterns and permanent body markings, and used these for population estimation using a capture–recapture analysis. The population estimate using the best fit null model Mowas 10 ± SE 1.2 giving an adult lion density of 5.6 ± SE 0.7 per 100 km2. Population viability analysis emphasized the importance of immigrants for the persistence of this small population. One immigrant in 2 years reduced the probability of extinction by 16%. Conservation of the habitat matrix to the south-east of the Sanctuary, used as a corridor for movement between Girnar and Gir, by declaring it an eco-sensitive zone would facilitate the long-term survival of the Girnar lion population.

Estimating lion population variables: prey and disease effects in Kruger National Park, South Africa

Context. Lion (Panthera leo Linnaeus, 1758) populations experience a range of ecological and human influences that affect their demography. Few lion populations have reliable estimates of population size, trends in these, or demographic profiles. Threats such as those imposed by diseases are thus hard to evaluate and respond to. Aims. To calibrate call-up stations and define survey effort required to achieve estimates with known precision, and extract age structures and estimate survival rates, to estimate lion numbers, sex and age structure and survival rates, and then to evaluate the effect of bovine tuberculosis (bTB) on estimates of lion density and survival. Methods.By using call-up stations, we developed a statistically robust approach to estimate selected population variables and evaluated the perceived threat of bTB in landscapes of varying prey biomass in the Kruger National Park. Key results. The size of the lion population was stable, although long intervals between present and historical estimates limit this conclusion. Density and survival rates associated positively with prey biomass, and a positive association was detected between the survival rate and bTB prevalence, with survival being higher in areas that had high prevalence of bTB. Male survival was lower than female survival, disregarding the effects of prey biomass or bTB prevalence. Body condition of lions was high, with scores lower at low to medium prey density. Conclusions. The effect of an exotic disease on the Kruger lion population may be negligible at present. Intra-specific competition in areas where lions live at high densities affects survival rate. However, droughts could disrupt the hierarchical influences of prey biomass and bTB prevalence on lion densities and survival. Implications. To evaluate the effect of an exotic disease on lion demography, population surveys should include age- and sex-structure assessments, complemented with focal studies of fecundity. This reflects the importance of understanding host–disease dynamics to inform management options.

Home range and habitat preference of female lions (Panthera leo persica) in Gir forests, India

The social organization of Asiatic lions (Panthera leo persica) differs from African lions (P. l. leo) in that breeding lionesses defend resource based territories while male coalitions maximize coverage of female groups. Thus, lion density in the Gir forests of India is dictated by female territory size. We studied the home range and habitat preference of lions using radio telemetry on seven lionesses spaced throughout the Gir between 2002 and 2005. Radio locations obtained by homing in were plotted on a classified (LISS III FCC) habitat map of Gir to obtain habitat use and availability. Habitat preference was computed using compositional analysis and Ivlev’s index. Average (±SE) 100% Minimum Convex Polygon (MCP) range of six lionesses was 48.2 ± 10.6 km2, 95% MCP was 34.7 ± 7.8 km2 and 95% fixed kernel range size was 32.5 ± 8.2 km2. Breeding female group density and group size was about 3 per 100 km2 and 1.3 (0.5 SD, n = 45) respectively. Lions were observed to show a habitat preference ( $$ \chi_{(6df)}^{2} = 11. 4 $$ , P = 0.08), the order of preference was Moist Mixed forests > Mixed forests > Savanna habitats > Teak-Acacia-Zizyphus-Anogeissus forests > Acacia-Lannea-Boswellia forests > Thorn and Scrub forests > Agriculture areas. Habitat preference during the day was for dense vegetation ( $$ \chi_{(6df)}^{2} = 35 $$ , P < 0.001). At night lions even ventured into agricultural fields. Our data suggests that dense habitats are preferred by lions in Gir to escape the heat of the day and to be in good cover when human activity was likely to be at its peak within forested areas.

Plenty of prey, few predators: what limits lions Panthera leo in Katavi National Park, western Tanzania?

We present a study from Katavi National Park and surrounding areas that assessed the size and structure of the lion population as a baseline for wildlife management. We assessed lion and prey species density directly by sample surveys that incorporated specific detection probabilities. By using three prey-biomass regression models we also indirectly estimated lion density based on the assumption that these indirect estimates represent the Park's carrying capacity for lions. To identify key factors influencing lion abundance we conducted Spearman Rank correlation and logistic regression analyses, using prey species abundance and distance to Park boundary as explanatory variables. The mean size of the lion population was 31–45% of the estimated carrying capacity, with considerably fewer subadult males observed than expected. Lions generally avoided areas of up to 3 km from the Park boundary and were not observed outside the Park. Abundance of common prey species was significantly correlated with distance to the Park boundary and lion abundance. Lion abundance was most strongly associated with waterbuck abundance/presence. Based on observed lion demography, an evaluation of hunting quotas in adjacent hunting blocks, and anecdotal information on traditional lion hunting, we hypothesize that anthropogenic mortality of lions outside Katavi National Park is affecting lion abundance within the Park. Our results suggest that estimating lion densities with prey-biomass regression models overestimates densities even inside protected areas if these areas are subject to natural and anthropogenic edge effects.

Interspecific competition influences reproduction in spotted hyenas

AbstractInterspecific competition among carnivores is an important determinant of predator population dynamics, and it may also affect lower trophic levels. Whereas considerable research has focused on effects of interspecific competition on threatened carnivore populations, here we examine the effects of interspecific competition on the most abundant large carnivore in Africa, the spotted hyena Crocuta crocuta. Specifically, we compared two populations of spotted hyenas to examine the sources of variation in fitness, including effects of competition with lions Panthera leo. Hyenas living in Amboseli National Park and the Masai Mara National Reserve, Kenya, were monitored from 2003 to 2005 and 1988 to 1992, respectively. Females reproduced at significantly higher rates in Amboseli, due to shorter lactation periods, though neither juvenile survival nor litter size differed between populations. Differences in reproduction were estimated to result in 24% greater lifetime reproductive success among Amboseli than among Mara females. We then tested alternative ecological hypotheses to explain these differences in fitness measures between populations. We found little support for hypotheses suggesting that population differences were due to variation in prey availability or dispersion, or to intraspecific competition either within or between hyena groups. Our results were most consistent with the hypothesis that population differences were due to variation in interspecific competition with lions. Hyenas in Amboseli lived at lower lion density, enjoyed higher rates of food intake despite less abundant prey, and scavenged more food from lions than did Mara hyenas. Our results indicate that competition with lions operated primarily via food competition, rather than direct killing, to generate the fitness differences.

Lion – prey relations in West and Central Africa

Most studies on the lion (Panthera leo) have been conducted in East and southern Africa. Information from West and Central Africa is scarce, probably because densities are generally lower: lion densities are typically between 1 and 3 lions/100 km (Bauer and Van Der Merwe 2004). This corresponds with low standing biomass or prey densities in West and Central Africa (East 1984; De Bie 1991). Here, we examine the sparsely available information on lion–prey relations, in particular prey preferences and predator-prey biomass ratio, in relation to ecological conditions in West and Central Africa. Our discussion is mainly based on data from six study areas in the Soudano-sahelian savannah belt: Niokolo Koba National Park (NP) in Senegal, ‘W’ NP in Niger, Pendjari NP in Benin, Zakouma NP in Chad and Waza NP and Bouba Njida NP in Cameroon. For comparison, we used available data from the Serengeti, Manyara and Kruger ecosystems in East and southern Africa (Schaller 1972; Mills and Funston 2003). Many publications describe lion–prey relations and hunting behaviour in East and southern Africa (e.g. Schaller 1972; Packer and Pusey 1997; Funston et al. 2001; Ogutu and Dublin 2002; Mills and Funston 2003). In the absence of data from West and Central Africa,

Modelling wildebeest population dynamics: implications of predation and harvesting in a closed system

Summary Predation upon ungulates is generally considered to have a stronger regulatory effect on sedentary than migratory populations, with migratory populations maintaining higher densities. The blue wildebeest Connochaetus taurinus is a migratory species that has suffered a general decline in numbers and distribution across its species range. Wildebeest suffer from a fragmented distribution together with isolation of populations in closed reserves, preventing migratory movements and potentially allowing predators to benefit from a ‘captive’ prey resource. In Pilanesberg National Park, South Africa, the declining blue wildebeest population (from 1074 in 1995 to 594 in 2001) is sedentary because the park (50 000 ha) is completely enclosed by fencing. This population was used to model the potential effects of predation and harvesting. The Pilanesberg population was then compared with other wildebeest populations in southern Africa. The model outputs demonstrated that increased levels of predation by lions Panthera leo on a ‘captive’ population of prey such as wildebeest, in combination with regular harvesting by park managers, can drive the population towards extinction. At lower levels of predation some other factor needs to act in combination with predation to drive the population into a decline. During our study the lion biomass density in Pilanesberg was almost three times greater than that predicted by regression models of the stable relationship between lion and prey biomass densities across African savannas. Furthermore, the ratio of lion numbers to prey numbers was substantially higher than in most other African reserves. Synthesis and applications. In African savannas, artificial closed systems provide advantages to large predators. If wildlife‐cropping schemes are implemented in such systems without careful monitoring and regulation of large predators, then ungulate populations can decline more rapidly than managers expect.

The effects of pastoralism and protection on the density and distribution of carnivores and their prey in the Mara ecosystem of Kenya

The overlap of large carnivores, livestock and people can engender conflicts that often threaten the future viability of carnivore populations in the pastoral systems of Africa. A playback survey of lions Panthera leo, spotted hyenas Crocuta crocuta and black-backed jackals Canis mesomelas and a transect count of wild herbivores was conducted in the Maasai Mara National Reserve and adjoining pastoral ranches to assess the effect of pastoralism and protection on the density and distribution of carnivores in June 2003. Reliability of the prey counts depended on an assumption of similar observability between the protected and pastoral areas, which we assessed using distance sampling in November 2003 and computer simulations and determined to be similar. Estimates of wild prey biomass density was 2.6 times higher in the ranches (14212 kg/km2) than in the reserve (5472 kg/km2) during this wet season count. Apparent hyena density estimates were 1.3 times higher in the ranches (0.561 hyenas/km2) than in the reserve (0.404 hyenas/km2), in correspondence with the regional pattern of prey density. This distribution of hyenas is biased towards the reserve, if it is dependent on prey density. Estimates of apparent jackal density were similar in both areas whereas lion density was anomalously 8.0 times lower in the ranches (0.046 lions/km2) than in the reserve (0.369 lions/km2). Lion and hyena densities and prey biomass did not differ between June 1991 (5172.273 kg/km2) and June 2003 (5472 kg/km2) in the reserve, but jackal density increased in the same period. Lions never responded to playbacks in the ranches, so the potential shift in lion behavioural response for different land use zones is another potential explanation for the patterns found here. We think a real shift in lion populations is a better explanation than a behavioural change in relation to playbacks based on additional data from independent systematic and intensive censuses and playback surveys conducted in the ranches. Lion populations in the pastoral ranches seemed headed for extinction, probably owing to conflicts with pastoralism, necessitating urgent conservation interventions that integrate pastoral economic welfare with large carnivore conservation goals to foster long-term viability of lion populations in the pastoral systems.

Spatial dynamics of lions and their prey along an environmental gradient

AbstractEstablishing the ecological determinants of the spatial dynamics of large African savanna mammals is necessary for understanding the cumulative impacts on the suitability and resilience of their natural habitats, of progressive habitat fragmentation and temporal shifts in climate, fire regimes and elephant browsing. Systematic directional gradients and small‐scale spatial dependence were evident in rainfall, herbivore biomass and lion density in the Masai Mara National Reserve during September 1990 to July 1992. Lion density, the biomass of resident and all herbivore species were autocorrelated within 4.3, 4.1 and 3.3 km, respectively, and peaked in areas of relatively low rainfall but higher microtopographic and vegetation heterogeneity and complexity and more diverse drainage systems. Rainfall influenced herbivore biomass and hence lion density non‐linearly and that influence was apparently modified by forage mineral nutrients, structural habitat complexity, degree of drainage and distance to waterpoints. Lion density was related to the biomass of resident herbivores, even after controlling for rainfall and spatial trends. Persistence of the recent decline in Mara woodlands and increasing human population along the reserve–ranch boundary would likely reduce the reserve's lion population because most lions spent the daytime within the vegetation mosaic fringing drainage lines, away from humans and domestic livestock.

Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, Kenya

AbstractWe studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2–0.4 lions km−2) and pride size (range 8–48) were high because of a high resident prey biomass (10 335 kg km−2) augmented by migrant prey to 26 092 kg km−2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March–June and an influx of subadults into the reserve during July–August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani.

Estimation of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park using a capture–recapture survey

A previous estimate of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park (KTP) was made over 20 years ago. This together with increased fears regarding the viability of the population as a result of recent killings of roaming animals, an observed increase in non-violent mortalities during 1996, and possible reduced genetic viability due to suspected isolation, prompted another investigation. Between October 1996 and December 1996,68 lions were captured and marked and subjected to two recapture (resighting) samples. The minimum estimate derived from direct enumeration of marked and unmarked individuals is between 100–103 individuals. Assessment of the adult and subadult population using the Lincoln-Petersen estimator and the software program NOREMARK gives a figure between 92 and 125. The current estimate is below the previous estimate of between 113 and 140 lions. Lion densities of 1.2 adult and subadult lions/100 km>2 in the semi-arid southern Kalahari are considerably lower than those in more mesic regions. Furthermore, there appears to be some demographic variability with the ratio of females to males being twice as high as that recorded 20 years ago.

Distribution and breeding of New Zealand sea lions Phocarctos hookeri on Campbell Island

Campbell Island is the only major breeding site for the New Zealand sea lion Phocarctos hookeri outside the Auckland Islands. Minimum pup production was estimated at 78 for the 1997/98 breeding season, compared with the only previous estimate of 122 from 1991/92, and represents less than 5% of the total pup production for the species. Sea lions at Campbell Island have a widespread distribution, clumped at the coast and scattered inland. Local concentrations of sea lions were seen at Davis Point, Sandy Bay and both Northeast and Southeast Harbours. Isolated individuals were found up to 1.5 km inland and at altitudes up to 250 m. Breeding females at Campbell Island are generally solitary and give birth inland, in contrast to the highly gregarious colonies seen on the coasts of the Auckland Islands. In some years a small breeding colony forms on the coast, often at Davis point, but its location is variable. Overall, the present distribution and abundance of sea lions on Campbell Island does not appear to differ considerably from previous reports stretching back as far as the 1950s. Line transects proved inappropriate for estimating sea lion density, due to a low encounter rate and poor visibility in dense vegetation. Future work could include surveys for pups, which aggregate on the coast during March or April.

Predator avoidance, breeding experience and reproductive success in endangered cheetahs, Acinonyx jubatus

I examine three hypotheses about predator avoidance behaviour: (1) avoidance increases an individual's reproductive success; (2) avoidance changes with breeding experience according to one of three described models; and (3) any reproductive or experience benefits accrued to individuals by avoidance are reflected in their spatial distribution. These hypotheses were tested on cheetahs which incur substantial juvenile mortality from predation by two larger competitors: spotted hyaenas, Crocuta crocuta, and lions, Panthera leo. To examine avoidance tactics, I played lion and hyaena vocalizations to individual female cheetahs. Lion avoidance increased with the statistical interaction between age and reproductive success, suggesting that it may be a learned behaviour, reinforced by successful reproductive events. This behaviour translated into a nonrandom spatial distribution of cheetahs with the most reproductively successful females found near lower lion densities than less successful females. Hyaena avoidance decreased with the interaction between age and reproductive success, suggesting that it is diminished by successful reproductive events, perhaps because a female cheetah switches from avoidance to using antipredator behaviours as she gets older. Hyaena avoidance behaviour translated into a spatial distribution with the most reproductively successful females found near lower hyaena densities than less successful females; however, younger females were found near lower hyaena densities than older females.

Spoor counts as indices of large carnivore populations: the relationship between spoor frequency, sampling effort and true density

1. Studies of large carnivore populations and, particularly, reliable estimates of population density are necessary for effective conservation management. However, these animals are difficult to study, and direct methods of assessing population size and density are often expensive and time‐consuming. 2. Indirect sampling, by counting spoor, could provide repeatable and inexpensive measures of some population parameters. The relationship between true population density and indirect sampling results has seldom been described in large carnivore studies. 3. In northern Namibia the population densities of leopards, lions and wild dogs were measured through recognition of individuals and groups. Spoor counts were then conducted independently, to assess the relationship between true density and the distribution of spoor. 4. Sampling effort, both in terms of the number of roads and total road distance in a sample zone, and the intensity of sampling, had a marked effect on the accuracy and precision of spoor frequency calculations. 5. In a homogeneous habitat, leopard spoor were evenly spread along different roads and spoor frequency was independent of road length. Taking into account very low sample sizes, the spoor density of leopards, lions and wild dogs showed a strong linear correlation with true density. The slope of the regression for leopards was different to that of lions and wild dogs.

The response of lions and spotted hyaenas to sound playbacks as a technique for estimating population size

Overall, 217 lions (&gt;1 year) Panthera leo (Linnaeus) and 2069 spotted hyaenas (&gt;8 mo) Crocuta crocuta (Erxleben) responded to broadcast vocalizations, call‐ins, during six surveys in the Masai Mara National Reserve, Kenya.Carnivore response varied seasonally and was significantly higher and more uniform when migratory prey were absent. Variation in wildebeest abundance, by affecting food availability, was the only significant predictor of response. Variability in response with overall prey abundance was higher for lions than hyaenas. Lion response occurred within a radius of 2·5 km, was independent of age and sex but dropped virtually to zero whenever lions possessed a carcass at the time of broadcasting.An independent total census recorded 547 lions (all ages) in the Reserve, 9·96% of which were nomads. This proportion increased by 7·94% following the influx of migrants and raised lion (&gt;1 year) density from 0·292 to 0·320 lions/km2. The call‐in estimate of 0·294±0·009 (95% c.l.) lions/km2 practically equalled the total count. The high precision and low bias (−0·224%) of this estimate imply that call‐in surveys are reliable and may be employed to effectively monitor carnivore populations in the long term. Under simple random sampling, covering about 20% of an area would seem adequate to produce reliable density estimates.

Lion density and population structure in the Selous Game Reserve: evaluation of hunting quotas and offtake

In 1992, tourist hunting in the Selous Game Reserve generated 1.28 million dollars for the Tanzanian government, of which 0·96 million dollars were returned to wildlife conservation. Lions (Panthera leo) are one of three critical species for tourist hunting, consistently generating 12%–13% of hunting revenue from 1988 to 1992. Because of their ecological and economic importance (and intrinsic value), it is important that lion quotas be set so that offtake is sustainable. The population density of lions in Selous ranges from 0·08 to 0·13 adults km−2, comparable to unhunted ecosystems. The adult sex ratio (36–41% male) and the ratio of cubs to adults (29% cubs) are similar to those of unhunted populations. The ratio of lions to hyaenas is lower in heavily hunted areas (0·17 lions/hyena) than in unhunted areas (0·43 lions/hyena). Hunting levels between 1989 and 1994 took 2·7–4·3% of adult males annually, which is sustainable. The current quota is 10–16% of the adult male population, which exceeds natural mortality rates for male lions. To remain stable if the quota was filled, the population would have to compensate via increased fecundity, increased juvenile survival, or an altered sex‐ratio. Compensation occurs in Selous by producing (or raising) more male than female cubs (66–81% of juveniles are male). Only 28% of the Selous quota was filled in 1992. The percentage of quota filled (both in Selous and nationwide) has dropped since 1988 as quotas have increased. The current intensity of lion hunting in Selous is sustainable, but the quota cannot be filled sustainably.

Limitation of African Wild Dogs by Competition with Larger Carnivores

African wild dogs (Lycaon pictus) are endangered largely because their population‐density is low under all conditions. Interspecific competition with larger carnivores may be a factor limiting wild dog density. The density of wild dogs on a 2600‐km2 area of the Selous Game Reserve (Tanzania) was 0.04 adults/km2. Spotted hyaena (Crocuta crocuta) density for the same area was estimated by audio playbacks as 0.32 hyaenas/km2. Lion (Panthera leo) density, determined from the ratio of hyaenas to lions, was 0.11 lions/km2. Across six ecosystems including Selous, there were strong negative correlations between wild dog and hyaena densities (r = −0.92; p = 0.01) and between wild dog and lion densities (r = −0.91; p = 0.03). Hyaenas out‐numbered wild dogs by ratios ranging from 8:1 to 122:1. Ratios of lions to wild dogs ranged from 3:1 to 21:1. The diets of hyaenas and wild dogs overlap extensively; those of wild dogs and lions show less overlap. Where hyaenas are common and visibility is good, interference competition from hyaenas at wild dog kills is common and reduces wild dogs’ feeding time. Where hyaena density is lower and visibility is poor, interference competition at wild dog kills is rare. Wild dogs are commonly killed by lions and occasionally by hyaenas. These data suggest that competition with spotted hyaenas may limit or exclude wild dogs when hyaena density is high. Competition with lions appears less intense, but direct predation by lions on wild dogs is important. Competition and predation by larger carnivores may be of broad importance to the conservation of wild dogs and other medium‐sized carnivores.