How does a human 'landscape of fear' shape trophic cascades

CURATOR

A pinboard by

Gavin Bonsen

PhD Student, University of Technology Sydney

PINBOARD SUMMARY

When gauging the ecological influence of humans, it is important to consider the interactions and relationships of humans; both within and between different human groups, as well as those with other species. Human cultures are diverse and differ across borders; as do people’s attitudes towards each other, wildlife and the environment. Opposing attitudes towards wildlife can create conflicting scenarios in which the importance of wildlife conservation, and thus, safety for wildlife, vary. Apex predators have, for a long time, been forced to endure intolerance from people. We now know that apex predators play key roles in ecosystem functioning through their interactions with prey and smaller predators in a process called ‘trophic cascades’. Predator-prey interactions (which can include humans as predators and apex predators as prey where persecution exists) are driven not only by the predators, but also by prey responses to predation risk. This risk varies across space and time, creating a ‘landscape of fear’ that the prey must carefully navigate. Yet to be considered are the ways in which the ability of apex predators to carry out these roles is driven by intra-human (human-human) relationships. Human conflict, as devastating as it may be, often opens up areas of relative safety for wildlife by creating human ‘no-go zones’. My research investigates the cascading ecological effects of conflict in the Middle East and how the landscape of fear changes for different species. Tolerance and persecution risk towards wolves vary across penetrable borders and regions. The main focus of my study is to determine spatial and temporal changes in animal movement and behaviour as a response to risk. Conflict creates dangerous areas for humans, which become safe for wolves. Low tolerance and protection laws create areas that are dangerous for wolves, which might become safe for prey and smaller predators.

2 ITEMS PINNED

Effects of humans on behaviour of wildlife exceed those of natural predators in a landscape of fear.

Abstract: Human disturbance can influence wildlife behaviour, which can have implications for wildlife populations. For example, wildlife may be more vigilant near human disturbance, resulting in decreased forage intake and reduced reproductive success. We measured the effects of human activities compared to predator and other environmental factors on the behaviour of elk (Cervus elaphus Linnaeus 1758) in a human-dominated landscape in Alberta, Canada.We collected year-round behavioural data of elk across a range of human disturbances. We estimated linear mixed models of elk behaviour and found that human factors (land-use type, traffic and distance from roads) and elk herd size accounted for more than 80% of variability in elk vigilance. Elk decreased their feeding time when closer to roads, and road traffic volumes of at least 1 vehicle every 2 hours induced elk to switch into a more vigilant behavioural mode with a subsequent loss in feeding time. Other environmental factors, thought crucial in shaping vigilance behaviour in elk (natural predators, reproductive status of females), were not important. The highest levels of vigilance were recorded on public lands where hunting and motorized recreational activities were cumulative compared to the national park during summer, which had the lowest levels of vigilance.In a human-dominated landscape, effects of human disturbance on elk behaviour exceed those of habitat and natural predators. Humans trigger increased vigilance and decreased foraging in elk. However, it is not just the number of people but also the type of human activity that influences elk behaviour (e.g. hiking vs. hunting). Quantifying the actual fitness costs of human disturbance remains a challenge in field studies but should be a primary focus for future researches. Some species are much more likely to be disturbed by humans than by non-human predators: for these species, quantifying human disturbance may be the highest priority for conservation.

Pub.: 12 Dec '12, Pinned: 31 Aug '17

What is a Trophic Cascade?

Abstract: Few concepts in ecology have been so influential as that of the trophic cascade. Since the 1980s, the term has been a central or major theme of more than 2000 scientific articles. Despite this importance and widespread usage, basic questions remain about what constitutes a trophic cascade. Inconsistent usage of language impedes scientific progress and the utility of scientific concepts in management and conservation. Herein, we offer a definition of trophic cascade that is designed to be both widely applicable yet explicit enough to exclude extraneous interactions. We discuss our proposed definition and its implications, and define important related terms, thereby providing a common language for scientists, policy makers, conservationists, and other stakeholders with an interest in trophic cascades.

Pub.: 25 Sep '16, Pinned: 31 Aug '17

How does a human 'landscape of fear' shape trophic cascades in the Middle East?