Predator (broad def): Any organism that Ex. Herbivores, blood-sucking leeches . •. Parasites. ❖ Consume part of host, not kill, 1 or few of relationships that. Types of Species Interactions. Exploitative interactions include: Predation; Herbivory; Parasitism. Parasitism. Parasites live in or on their host's body and often. Define interspecific competition, mutualism, predation, herbivory, and parasitism, and provide Parasitism: an interaction with a parasite and a parasite host. (+/-) ex: Describe the mutualistic relationship between corals and dinoflagellates.
Female Photuris firefliesfor example, copy the light signals of other species, thereby attracting male fireflies, which they capture and eat.
Venom and Evolution of snake venom Many smaller predators such as the box jellyfish use venom to subdue their prey,  and venom can also aid in digestion as is the case for rattlesnakes and some spiders.
Predation - Wikipedia
These changes are explained by the fact that its prey does not need to be subdued. Antipredator adaptation To counter predation, prey have a great variety of defences. They can try to avoid detection.
They can detect predators and warn others of their presence. If detected, they can try to avoid being the target of an attack, for example, by signalling that a chase would be unprofitable or by forming groups. If they become a target, they can try to fend off the attack with defences such as armour, quills, unpalatability or mobbing; and they can escape an attack in progress by startling the predator, shedding body parts such as tails, or simply fleeing.
They can also adopt behaviour that avoids predators by, for example, avoiding the times and places where predators forage. Camouflage and Mimicry Dead leaf mantis 's camouflage makes it less visible to both predators and prey. Syrphid hoverfly misdirects predators by mimicking a waspbut has no sting. Prey animals make use of a variety of mechanisms including camouflage and mimicry to misdirect the visual sensory mechanisms of predators, enabling the prey to remain unrecognized for long enough to give it an opportunity to escape.
Camouflage delays recognition through coloration, shape, and pattern. In mimicry, an organism has a similar appearance to another species, as in the drone flywhich resembles a bee yet has no sting. It is lowest for those such as woodpeckers that excavate their own nests and progressively higher for those on the ground, in canopies and in shrubs.
Birds also choose appropriate habitat e. Similarly, some mammals raise their young in dens. Due to the success of aposematic organisms, organisms that are not noxious, and therefore vulnerable to predation, may exhibit similar coloring patterns to aposematic organisms, in order to falsely repel their predators.
This is another type of defense called Batesian mimicry. Batesian mimicry is just one of two types of mimicry and occurs when a palatable species imitates a non-palatable species.
This type of mimicry is only successful if the population of the palatable species is smaller than the population of the non-palatable species. Mimicry Prey also use coloring patterns to blend into their surroundings. Crypsis or camoflauge is a means by which organisms use their shape and their coloring to blend into their environment, rather than standing out.
Clearly, color is an important defense that can be used in multiple ways to protect prey from their predators.
Like camoflauge, several forms of prey defenses are intuitively obvious. Fighting, escaping, and armor are three very straightforward concepts. Prey instinctively fight back against their predators as a form of self defense.
Organisms may also try to escape or flee from their predators by using a startle response or indirection. During this type of defense, the prey perform an action that startles or distracts the predator long enough for them to escape. For example, some toads shoot blood from their eyes and other animals imitate loud sounds. Armor is a form of physical protection. Things such as the shells on turtles, spines or needles on a pufferfish, and thorns on a plant are examples of different types of armor.
Other organisms employ intimidation or threat techniques that make them appear larger than they really are. Hissing and growling are examples of intimidation techniques that display aggression and create the illusion of an increased threat to predators. Satiation and masting are intertwined ideas that result in the survival of some prey at the expense of others.
Masting is more commonly thought of as herding and occurs when organisms travel in very large groups. Because of the size of the groups, predators can only consume so many of them, resulting in the survival of some prey, but not all. Predation[ edit ] The predation hypothesis states that predators reduce prey. Fewer prey liberates resources, which in turn are used by other species, which increases species richness.
The classic explanation is this: As hare numbers increase, there is more food available for the lynx, allowing the lynx population to increase as well. When the lynx population grows to a threshold level, however, it kills so many hares that the hare population begins to decline. This is followed by a decline in the lynx population due to scarcity of food. When the lynx population is low, the hare population begins to increase—due, at least in part, to low predation pressure—starting the cycle anew.
Ecology/Predation and Herbivory
Today, ecologists no longer think that the cycling of the two populations is entirely controlled by predation. For instance, it appears that availability of plant foods eaten by the hares—which decreases when hares become too abundant, due to competition—may also be a factor in the cycle.
Defense mechanisms against predation When we study a community, we must consider the evolutionary forces that have acted—and continue to act! Species are not static but, rather, change over generations and can adapt to their environment through natural selection. Predator and prey species both have adaptations—beneficial features arising by natural selection—that help them perform better in their role.
For instance, prey species have defense adaptations that help them escape predation. These defenses may be mechanical, chemical, physical, or behavioral. Mechanical defenses, such as the presence of thorns on plants or the hard shell on turtles, discourage animal predation and herbivory by causing physical pain to the predator or by physically preventing the predator from being able to eat the prey.
Chemical defenses are produced by many animals as well as plants, such as the foxglove, which is extremely toxic when eaten.
Predation & herbivory (article) | Ecology | Khan Academy
The millipede in the lower panel below has both chemical and mechanical defenses: The top left image shows the long, sharp thorns of a honey locust tree. The top right image shows the domed shell of a tortoise. The bottom left image shows the pink, bell-shaped flowers of a foxglove. The bottom right image shows a millipede curled into a ball. For instance, the crab spider has the coloration and body shape of a flower petal, which makes it very hard to see when it's standing still against the background of a real flower.