Usage of Specialized Fence-Gaps in a Black Rhinoceros Conservancy in Kenya

Fencing is increasingly used in wildlife conservation. Keeping wildlife segregated from local communities, while permitting wildlife access to the greater landscape matrix is a complex task. We investigated the effectiveness of specially designed fence-gaps on animal movement at a Kenyan rhinoceros conservancy, using camera-traps over a four-year period. The fence-gap design restricted the movement of black (Diceris bicornis) and white rhinoceroses (Ceratotherium simum simum) but permitted the movement of other species. We documented over 6000 crossing events of over 50 000 individuals which used the fence-gaps to enter or leave the conservancy. We recorded 37 mammal species and two species of bird using the fence-gaps. We conclude that this fence-gap design is effective at restricting rhinoceros movement and at permitting other wildlife movement into and out of the conservancy. We recommend that fenced-in rhinoceros conservancies that desire enhanced connectivity consider this fence-gap design to help re-connect their reserves to the outside landscape matrix while continuing to provide enhanced protection for their rhinoceroses

Lion ecology and socio-spatial impacts of trophy hunting in Zimbabwe

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Do wildlife corridors link or extend habitat? Insights from elephant use of a Kenyan wildlife corridor

Human encroachment on wildlife habitats is leading to increased fragmentation; hence, there is an increasing focus on improving connectivity between remaining habitat. Large, wide-ranging species such as the African elephant, (Loxodonta africana), are particularly vulnerable due to their extensive habitat requirements. Wildlife corridors have been created to facilitate movement, with little knowledge to date on whether they serve their intended function as transit routes, or whether they simply extend the available habitat for occupancy. We collected data on elephant behaviour in the Mount Kenya Elephant Corridor, with the aim of quantifying the utility of the corridor. A grid of 25 camera traps was used to survey the 478 ha corridor over 11 weeks. Cameras recorded over 43,000 photos with 694 separate events triggered by elephants. Patterns of use varied spatially and temporally, indicating that certain areas were treated as habitat extension, while others were predominantly for transit. These differences were likely due to variation in vegetation cover and levels of human disturbance. Corridor use differed amongst individuals, suggesting that use may depend on both the characteristics of the corridor itself and the social or resource needs of individual elephants.</p

Testing the effects of perimeter fencing and elephant exclosures on lion predation patterns in a Kenyan wildlife conservancy

The use of fences to segregate wildlife can change predator and prey behaviour. Predators can learn to incorporate fencing into their hunting strategies and prey can learn to avoid foraging near fences. A twelve-strand electric predator-proof fence surrounds our study site. There are also porous one-strand electric fences used to create exclosures where elephant (and giraffe) cannot enter in order to protect blocs of browse vegetation for two critically endangered species, the black rhinoceros (Diceros bicornis) and the Grevy’s zebra (Equus grevyi). The denser vegetation in these exclosures attracts both browsing prey and ambush predators. In this study we examined if lion predation patterns differed near the perimeter fencing and inside the elephant exclosures by mapping the location of kills. We used a spatial analysis to compare the predation patterns near the perimeter fencing and inside the exclosures to predation in the rest of the conservancy. Predation was not over-represented near the perimeter fence but the pattern of predation near the fence suggests that fences may be a contributing factor to predation success. Overall, we found that predation was over-represented inside and within 50 m of the exclosures. However, by examining individual exclosures in greater detail using a hot spot analysis, we found that only a few exclosures contained lion predation hot spots. Although some exclosures provide good hunting grounds for lions, we concluded that exclosures did not necessarily create prey-traps per se and that managers could continue to use this type of exclusionary fencing to protect stands of dense vegetation

Роль и место университетов в инновационно-промышленных кластерах

Wildlife fencing has become more prevalent throughout Africa, although it has come with a price of increased habitat fragmentation and loss of habitat connectivity. In an effort to increase connectivity, managers of fenced conservancies can place strategic gaps along the fences to allow wildlife access to outside habitat, permitting exploration, dispersal and seasonal migration. Wildlife can become accustomed to certain movement pathways and can show fidelity to these routes over many years, even at the path level. Our study site has three dedicated wildlife crossings (fence-gaps) in its 142 km perimeter fence, and we continuously monitor these fence-gaps with camera-traps. We monitored one fence-gap before and after a 1.49 km fence section was completely removed and 6.8 km was reconfigured to leave only a two-strand electric fence meant to exclude elephant and giraffe, all other species being able to cross under the exclusionary fence. The removal and reconfiguration of the fence effectively rendered this fence-gap (which was left in place structurally) as a “ghost” fence-gap, as wildlife now had many options along the 8.29 km shared border to cross into the neighboring habitat. Although we documented some decline in the number of crossing events at the ghost-gap, surprisingly, 19 months after the total removal of the fence, we continued to document the usage of this crossing location by wildlife including by species that had not been previously detected at this location. We discuss potential drivers of this persistent and counterintuitive behavior as well as management implications

Data from: Testing the prey-trap hypothesis at two wildlife conservancies in Kenya

Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies

Testing the Prey-Trap Hypothesis at Two Wildlife Conservancies in Kenya

Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies

The electroencephalograph during anesthesia and emergence in infants and children.

BACKGROUND The characteristics of the electroencephalogram (EEG) during anesthesia in children are poorly described. An understanding of the EEG during anesthesia may help explain and predict the performance of EEG-derived depth of anesthesia monitors in children. This study aims to describe the association between age and some basic characteristics of the EEG during nonstandardized anesthesia in children and infants. METHODS Sixty-four children aged 9 days to 12 years were enrolled in this observational physiological study. Anesthesia was given at the discretion of the anesthetist. EEG was recorded from after induction to emergence using a BRM2 brain monitor ''BrainZ Instruments, Auckland, New Zealand'' in parietal and frontal montages. For comparison, 90% spectral edge frequency (SEF-90) and power were determined at three points (equilibrium during anesthesia, when the volatile agent was discontinued and at emergence), and children were divided into three age groups (0-6 months, 6-24 months and 2-12 years). RESULTS Fifty-seven children had artifact-free EEG data. From equilibrium to emergence the mean forehead power decreased substantially in children aged 2-12 years (3171-153 microV(2), P < 0.001) and 6-24 months (756-140 microV(2), P < 0.001) but no difference was found in infants aged 0-6 months (93-63 microV(2), P = 0.4). From equilibrium to emergence mean forehead spectral edge frequency increased in children aged 2-12 years (10.8-13.7 Hz, P = 0.01) but no change was found in children aged 6-24 months (12.7-12.7 Hz, P = 0.9) or 0-6 months (9.45-7.26 Hz, P = 0.08). Throughout emergence, infants demonstrated a discontinuous EEG pattern with intermittent bursts separated with low amplitude. CONCLUSIONS During anesthesia, the EEG in infants is fundamentally different from the EEG in older children. This study supports the need for specific infant-derived algorithms if EEG-derived anesthesia depth monitors are to be used in infants

Seasonal Diet and Prey Preference of the African Lion in a Waterhole-Driven Semi-Arid Savanna

International audienc

Data from: Understanding patch departure rules for large carnivores: lion movements support a patch-disturbance hypothesis

We test two hypotheses that could account for patch departure by large mammalian carnivores. One hypothesis is the unsuccessful hunt hypothesis, where carnivores leave an area after an unsuccessful hunt but continue hunting in the same area after a successful hunt. The second hypothesis is the patch disturbance hypothesis, where carnivores depart the area after a successful hunt because of behavioral responses of prey to predator presence. We used GPS-collars to monitor the movements of African lions (Panthera leo) and identified their kill sites to distinguish between these two hypotheses. Lions moved to a different area (>5 km) after 87 percent of the kills, which supports the patch disturbance hypothesis for patch departure behavior of large mammalian carnivores