The ecology of fear is a conceptual framework describing the psychological impact that predator-induced stress experienced by animals has on populations and ecosystems. Within ecology, the impact of predators has been traditionally viewed as limited to the animals that they directly kill, while the ecology of fear advances evidence that predators may have a far more substantial impact on the individuals that they predate, reducing fecundity, survival and population sizes. [1] [2] To avoid being killed, animals that are preyed upon will employ anti-predator defenses which aid survival but may carry substantial costs. [1]
The concept was coined in the 1999 paper "The Ecology of Fear: Optimal Foraging, Game Theory, and Trophic Interactions", [3] which argued that "a predator [...] depletes a food patch [...] by frightening prey rather than by actually killing prey." [4]
In the 2000s, the ecology of fear gained attention after researchers identified an impact of the reintroduction of wolves into Yellowstone on the regrowth of aspen and willows because of a substantial reduction in the numbers of elk in the park through killing. Some studies also indicated that the wolves affected the grazing intensity and patterns of the elk because they felt less secure when feeding. [2] Critics have put forward alternative explanations for the regrowth, other than the wolf reintroduction. [2] [5]
The consideration of wolves as a charismatic species and the fame of Yellowstone led to widespread media attention of the concept, including a mention in The New York Times and a fold-out illustration of the impact of wolves on Yellowstone in the March 2010 edition of the National Geographic. [5] There has also been a popular YouTube video How Wolves Change Rivers, which has been described as a vast overstatement by some scientists. [2]
A 2010 study found that sharks, like wolves, may have the capacity to create an ecology of fear in the ecosystems which they inhabit. [6] In 2012, a study indicated that the ecology of fear may also be applicable to parasites, with evidence suggesting that animals abandon feeding both because of predator and parasite avoidance. [7]
Some critics of the concept argue that the "cognitive and emotional aspects of avoiding predation remain unknown" and that this is true for "virtually all studies of 'the ecology of fear'". [8]
Analogous research has been applied to host-parasite and host-pathogen interactions based on the ecology of fear. [9] [10] This research is alternatively called the "ecology of disgust". [11]
The landscape of fear is a model based on the ecology of fear, which asserts that the behaviour of animals that are preyed upon is shaped by psychological maps of their geographical surroundings which accounts for the risk of predation in certain areas. [12] [13]
A 2011 paper described how exposure to predators as life-threatening psychological stressors is used in animal models of post-traumatic stress disorder (PTSD); these models are also used to emulate the experience of PTSD in humans and the authors suggested a collaboration between ecologists and neuroscientists to study the "neurological effects of predator-induced fear and stress in animals in the wild." [14]
In 2019, a study identified lasting effects on behavior and PTSD-like changes in the brains of wild animals caused by fear-inducing interactions with predators. [15]
Studies have found that the fear of humans can have substantial impacts on animal behaviour, [16] including on top predators such as pumas. [17] Humans may also create an ecology of fear by reintroducing predators into areas where they no longer live; the moral philosopher Oscar Horta argues against such reintroductions, asserting that they conflict with the well-being and interests of the animals already living in the environment. [18]
The coyote is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological niche as the golden jackal does in Eurasia. The coyote is larger and more predatory and was once referred to as the American jackal by a behavioral ecologist. Other historical names for the species include the prairie wolf and the brush wolf.
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation and parasitoidism. It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators.
The cougar, also known as the puma, mountain lion, catamount, or panther, is a large cat native to the Americas, second in size only to the stockier jaguar. They are not technically grouped with the "true" big cats, as they are slightly smaller than other big cats, and they lack the vocal physiology to roar. Its range spans the Canadian Provinces of the Yukon, British Columbia, and Alberta, the Rocky Mountains, and other areas in the Western United States. Their range extends further south through Mexico, where they are found in nearly every state, to the Amazon Rainforest and the southern Andes Mountains in Patagonia. The puma inhabits every mainland country in Central and South America, making it the most widely distributed large, wild, terrestrial mammal in the Western Hemisphere, and one of the most widespread on planet Earth. It is an adaptable, generalist species, occurring in most American habitat types. It prefers habitats with dense underbrush and rocky areas for stalking but also lives in open areas.
A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf, are also apex predators.
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine/vespertinal, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylight and of darkness, respectively. Some crepuscular animals may also be active by moonlight or during an overcast day. Matutinal animals are active only before sunrise, and vespertine only after sunset.
Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment where the animal lives.
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding behavior. Scavengers play an important role in the ecosystem by consuming dead animal and plant material. Decomposers and detritivores complete this process, by consuming the remains left by scavengers.
An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own.
Surplus killing, also known as excessive killing, henhouse syndrome, or overkill, is a common behavior exhibited by predators, in which they kill more prey than they can immediately eat and then they either cache or abandon the remainder. The term was invented by Dutch biologist Hans Kruuk after studying spotted hyenas in Africa and red foxes in England. Some of the other animals which have been observed engaging in surplus killing include orcas, zooplankton, humans, damselfly naiads, predaceous mites, martens, weasels, honey badgers, jaguar, leopards, lions, wolves, spiders, brown bears, American black bears, polar bears, coyotes, lynxes, minks, raccoons and dogs.
The elk, or wapiti, is the second largest species within the deer family, Cervidae, and one of the largest terrestrial mammals in its native range of North America and Central and East Asia. The word "elk" originally referred to the European variety of the moose, Alces alces, but was transferred to Cervus canadensis by North American colonists. The name "wapiti" derives from a Shawnee and Cree word meaning "white rump" for the distinctive light fur in the rear region, just like the Bighorn Sheep.
Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. For example, a top-down cascade will occur if predators are effective enough in predation to reduce the abundance, or alter the behavior of their prey, thereby releasing the next lower trophic level from predation.
In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization".
The history of wolves in Yellowstone includes the extirpation, absence and reintroduction of wild populations of the gray wolf to Yellowstone National Park and the Greater Yellowstone Ecosystem. When the park was created in 1872, wolf populations were already in decline in Montana, Wyoming and Idaho. The creation of the national park did not provide protection for wolves or other predators, and government predator control programs in the first decades of the 1900s essentially helped eliminate the gray wolf from Yellowstone. The last wolves were killed in Yellowstone in 1926. After that, sporadic reports of wolves still occurred, but scientists confirmed that sustainable wolf populations had been extirpated and were absent from Yellowstone during the mid-1900s.
Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. Intraguild predation is common in nature and can be asymmetrical, in which one species feeds upon the other, or symmetrical, in which both species prey upon each other. Because the dominant intraguild predator gains the dual benefits of feeding and eliminating a potential competitor, IGP interactions can have considerable effects on the structure of ecological communities.
Antipredatory behaviors are actions an animal performs to reduce or rid themselves of the risk of being prey. Many studies have been done on elk to see what their antipredator behaviors consist of.
Wild animal suffering is the suffering experienced by nonhuman animals living outside of direct human control, due to harms such as disease, injury, parasitism, starvation and malnutrition, dehydration, weather conditions, natural disasters, and killings by other animals, as well as psychological stress. Some estimates indicate that these individual animals make up the vast majority of animals in existence. An extensive amount of natural suffering has been described as an unavoidable consequence of Darwinian evolution and the pervasiveness of reproductive strategies which favor producing large numbers of offspring, with a low amount of parental care and of which only a small number survive to adulthood, the rest dying in painful ways, has led some to argue that suffering dominates happiness in nature.
Pursuit predation is a form of predation in which predators actively give chase to their prey, either solitarily or as a group. It is an alternate predation strategy to ambush predation — pursuit predators rely on superior speed, endurance and/or teamwork to seize the prey, while ambush predators use concealment, luring, exploiting of surroundings and the element of surprise to capture the prey. While the two patterns of predation are not mutually exclusive, morphological differences in an organism's body plan can create an evolutionary bias favoring either type of predation.
Disease ecology is a sub-discipline of ecology concerned with the mechanisms, patterns, and effects of host-pathogen interactions, particularly those of infectious diseases. For example, it examines how parasites spread through and influence wildlife populations and communities. By studying the flow of diseases within the natural environment, scientists seek to better understand how changes within our environment can shape how pathogens, and other diseases, travel. Therefore, diseases ecology seeks to understand the links between ecological interactions and disease evolution. New emerging and re-emerging infectious diseases are increasing at unprecedented rates which can have lasting impacts on public health, ecosystem health, and biodiversity.
The predation problem or predation argument refers to the consideration of the harms experienced by animals due to predation as a moral problem, that humans may or may not have an obligation to work towards preventing. Discourse on this topic has, by and large, been held within the disciplines of animal and environmental ethics. The issue has particularly been discussed in relation to animal rights and wild animal suffering. Some critics have considered an obligation to prevent predation as untenable or absurd and have used the position as a reductio ad absurdum to reject the concept of animal rights altogether. Others have criticized any obligation implied by the animal rights position as environmentally harmful.
In ecology, hunting success is the proportion of hunts initiated by a predatory organism that end in success. Hunting success is determined by a number of factors such as the features of the predator, timing, different age classes, conditions for hunting, experience, and physical capabilities. Predators selectivity target certain categories of prey, in particular prey of a certain size. Prey animals that are in poor health are targeted and this contributes to the predator's hunting success. Different predation strategies can also contribute to hunting success, for example, hunting in groups gives predators an advantage over a solitary predator, and pack hunters like lions can kill animals that are too powerful for a solitary predator to overcome, like a megaherbivore.