predator–prey population dynamics. For example, McLaren and Peterson () studied relationships between wolves, moose, and balsam fir (Abies balsamea). Predation, herbivory, and parasitism coexist within ecological communities. Think of wolves hunting moose, owls hunting mice, or shrews hunting worms and . The Banff refuge may influence Bow Valley predator-prey dynamics To test this hypothesis, we used 26 years of wolf and elk population of the avoidance relationship between wolves and humans , . into distinct ecological zones based upon variation in human, wolf and elk densities , .
Food web ; Population ecology ; Population viability ; Theoretical ecology ; Trophic ecology The populations of wolves and moose on Isle Royale have fluctuated dramatically.
The first moose arrived on the island in the early s, possibly by swimming from the mainland or by "stocking" carried out by humans. The first wolves were a pair of animals that walked across an ice bridge from Ontario during a particularly cold winter in All of the subsequent wolves inhabiting the island descended from the initial pair, which led to population difficulties resulting from inbreeding.
Investigators initially envisioned that a population equilibrium would have been reached between the predatory wolf and moose prey populations.
However, this has not been observed. Instead, the wolf and moose populations have shifted antagonistically between high and low points.
For example, the moose population which was expected to hover around individuals has ranged between to sincewhereas the wolf population which was expected to hover around 25 individuals has fluctuated between 2 and Mathematical ecology ; Population genetics Scientists estimate that there are only 2 remaining wolves on Isle Royale.
As a result, the numbers of moose on the island are increasing at a very rapid pace.
Thus, conservationists fear that the growing moose population will eliminate the limited vegetation that they eat and need in order to survive, thereby leading to starvation of the animals. However, a continued presence of a genetically healthy wolf population on the island would provide a check on the booming moose numbers.
Therefore, a new plan is being undertaken by the U.
The Wolf and the Moose: Natural Enemies That Need Each Other - Scientific American
National Park Service to restock the wolf population. If the prey flees in a straight line, capture depends only on the predator's being faster than the prey. The method is used by human hunter-gatherers and in canids such as African wild dogs and domestic hounds. The African wild dog is an extreme persistence predator, tiring out individual prey by following them for many miles at relatively low speed, compared for example to the cheetah 's brief high-speed pursuit.
The Wolf and the Moose: Natural Enemies That Need Each Other
These very large marine predators feed on planktonespecially krilldiving and actively swimming into concentrations of plankton, and then taking a huge gulp of water and filtering it through their feathery baleen plates.
Osprey tears its fish prey apart, avoiding dangers such as sharp spines.
Once the predator has captured the prey, it has to handle it: Some catfish such as the Ictaluridae have spines on the back dorsal and belly pectoral which lock in the erect position; as the catfish thrashes about when captured, these could pierce the predator's mouth, possibly fatally. Some fish-eating birds like the osprey avoid the danger of spines by tearing up their prey before eating it.
Cooperative hunting In social predation, a group of predators cooperates to kill prey. This makes it possible to kill creatures larger than those they could overpower singly; for example, hyenasand wolves collaborate to catch and kill herbivores as large as buffalo, and lions even hunt elephants. For example, when mixed flocks of birds forage, the birds in front flush out insects that are caught by the birds behind.
Spinner dolphins form a circle around a school of fish and move inwards, concentrating the fish by a factor of Predators of different species sometimes cooperate to catch prey. In coral reefswhen fish such as the grouper and coral trout spot prey that is inaccessible to them, they signal to giant moray eelsNapoleon wrasses or octopuses.
These predators are able to access small crevices and flush out the prey. Solitary predators have more chance of eating what they catch, at the price of increased expenditure of energy to catch it, and increased risk that the prey will escape.
These include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. Many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. Some predators such as snakes and fish-eating birds like herons and cormorants swallow their prey whole; some snakes can unhinge their jaws to allow them to swallow large prey, while fish-eating birds have long spear-like beaks that they use to stab and grip fast-moving and slippery prey.
Lions can attack much larger prey, including elephants, but do so much less often. Predators are often highly specialized in their diet and hunting behaviour; for example, the Eurasian lynx only hunts small ungulates.
When prey have a clumped uneven distribution, the optimal strategy for the predator is predicted to be more specialized as the prey are more conspicuous and can be found more quickly;  this appears to be correct for predators of immobile prey, but is doubtful with mobile prey. This has led to a correlation between the size of predators and their prey. Size may also act as a refuge for large prey. For example, adult elephants are relatively safe from predation by lions, but juveniles are vulnerable.
Members of the cat family such as the snow leopard treeless highlandstiger grassy plains, reed swampsocelot forestfishing cat waterside thicketsand lion open plains are camouflaged with coloration and disruptive patterns suiting their habitats.