Factors influencing space-use and kill distribution of sympatric lion prides in a semi-arid savanna landscape.

Understanding lions' (Panthera leo) space-use is important for the management of multi-species wildlife systems because lions can have profound impacts on ecosystem-wide ecological processes. Semi-arid savanna landscapes are typically heterogeneous with species space-use driven by the availability and distribution of resources. Previous studies have demonstrated that lions select areas close to water as encounter rates with prey are higher and hunting success is greater in these regions. Where multiple lion prides exist, landscape partitioning is expected to follow a despotic distribution in which competitively superior prides occupy high-quality areas while subordinates select poorer habitats. In this study, Global Positioning System collar data and logistic regression were used to investigate space-use and hunting success among 50% of lion prides at Malilangwe Wildlife Reserve, Zimbabwe. Our findings show that lion space-use was driven by surface water availability and that home range selection was socially hierarchical with the dominant pride occupying habitat in which water was most abundant. In addition, we found that the effect of shrub cover, clay content and soil depth on kill probability was area specific and not influenced by hierarchical dominance. Where multiple lion prides are studied, we recommend treating prides as individual units because pooling data may obscure site and pride specific response patterns.

An outbreak of Gynanisa maja (Lepidoptera: Saturniidae) larvae in the south-eastern lowveld of Zimbabwe.

The larvae of speckled emperor moths (Gynanisa maja) are important plant defoliators in savanna ecosystems of southern Africa and a valuable food resource for indigenous communities. Population explosions of G. maja larvae can negatively impact an area's primary productivity thereby altering herbivory patterns and associated ecosystem processes. Harvests of the larvae enhance socio-economic livelihoods of local people by providing a source of protein and improving household incomes. We report on a population outbreak of G. maja larvae that occurred in south-eastern Zimbabwe between December 2022 and January 2023 and discuss the ecological and social significance of the event. A total biomass weight of 5811 tons of G. maja larvae was estimated over the area of the outbreak and extensive defoliation was recorded in Colophospermum mopane trees. We could not associate the outbreak with any obvious environmental conditions and speculate that it may have been caused by subtle triggers that are not easily identified.

The effect of competing carnivores on the feeding behaviour of leopards (Panthera pardus) in an African savanna.

Knowledge of competition dynamics among Africa's large carnivores is important for conservation. However, investigating carnivore behaviour in the field can be challenging especially for species that are difficult to access. Methods that enable remote collection of data provide a means of recording natural behaviour and are therefore useful for studying elusive species such as leopards (Panthera pardus). Camera traps and Global Positioning System (GPS) collars are powerful tools often used independently to study animal behaviour but where their data are combined, the interpretation of a species' behaviours is improved. In this study we used data from baited camera trap stations to investigate the feeding habits of leopards at Malilangwe Wildlife Reserve, Zimbabwe. We investigated the influence of spotted hyenas, lions and other competing leopards on the feeding duration of leopards using Generalized Linear Mixed Effects Modelling. To test the influence of competing predators on resting distances from bait sites, eight leopards were fitted with GPS collars. Results showed that leopards spent the shortest time feeding on the baits in the presence of competing male leopards compared to other predators while lion presence caused animals to rest farthest from bait sites. Interaction analysis indicated that small-bodied leopards spent significantly shorter durations feeding when spotted hyenas were present. Our findings demonstrate that competition from guild carnivores has negative impacts on the food intake of leopards, which may have implications for fitness and survival. This study provides a snapshot of the competition dynamics at bait sites which may give insight to ecosystem level interactions among large carnivores in savanna ecosystems.

A baited-camera trapping method for estimating the size and sex structure of African leopard (Panthera pardus) populations.

Amongst Africa's large predators, leopards (Panthera pardus) are arguably the most elusive carnivore. Information on the species is lacking in most areas where they are found. This is because leopards are largely solitary, cryptically coloured and nocturnal making the collection of accurate population data difficult. As a result, population estimates from methods such as spoor and scat counts are less reliable. This is a concern because accurate census data are essential for informed policy and management of threatened species such as leopards. Camera trapping has emerged as a powerful tool for inventorying and monitoring carnivores in their natural habitats. Pictures from camera traps allow unambiguous individual identification making these data useful for generating accurate population estimates from capture-recapture analysis. Conventionally, camera trapping uses two cameras to record passing subjects at unbaited stations but the design usually suffers from low capture rates. Here we report on the Baited-Camera Trapping (BCT) method which uses bait and single cameras at sampling stations to survey free ranging leopards. Using bait to improve the quality of data collected in population studies is not a new strategy but arranging baits and cameras according to the BCT method is a novel approach to achieving this goal. We show that the method can significantly enhance capture rates, improve individual identification and reduce cost when sampling leopards. Furthermore, the method allows easy sex determination and collection of morphometric data from camera trap photographs. The BCT method has been tested in semi-arid savannas and we give recommendations for application in other environments and species.•The BCT method uses baits and single cameras to record leopards at sampling stations.•The provision of a leading pole enables easier individual identification and sex determination.•The method can be used to investigate multiple population monitoring questions which enhances its cost-benefit ratio.

Measuring body dimensions of leopards (Panthera pardus) from camera trap photographs.

Measurement of body dimensions of carnivores usually requires the chemical immobilization of subjects. This process can be dangerous, costly and potentially harmful to the target individuals. Development of an alternative, inexpensive, and non-invasive method therefore warrants attention. The objective of this study was to test whether it is possible to obtain accurate measurements of body dimensions of leopards from camera trap photographs. A total of 10 leopards (Panthera pardus) were captured and collared at Malilangwe Wildlife Reserve, Zimbabwe from May 7 to June 20, 2017 and four body measurements namely shoulder height, head-to-tail, body, and tail length were recorded. The same measurements were taken from 101 scaled photographs of the leopards recorded during a baited-camera trapping (BCT) survey conducted from July 1 to October 22, 2017 and differences from the actual measurements calculated. Generalized Linear Mixed Effects Models were used to determine the effect of type of body measurement, photographic scale, posture, and sex on the accuracy of the photograph-based measurements. Type of body measurement and posture had a significant influence on accuracy. Least squares means of absolute differences between actual and photographic measurements showed that body length in the level back-straight forelimb-parallel tail posture was measured most accurately from photographs (2.0 cm, 95% CI [1.5-2.7 cm]), while head-to-tail dimensions in the arched back-bent forelimb-parallel tail posture were least accurate (8.3 cm, 95% CI [6.1-11.2 cm]). Using the BCT design, we conclude that it is possible to collect accurate morphometric data of leopards from camera trap photographs. Repeat measurements over time can provide researchers with vital body size and growth rate information which may help improve the monitoring and management of species of conservation concern, such as leopards.