Hunting and foraging

Foraging covers far more than predators chasing prey. It includes a grazing tortoise cropping vegetation, a hummingbird visiting flowers, a whale straining plankton, and a fox digging for invertebrates. Biologists often analyse these behaviours through optimal foraging theory, a framework that examines how the energy and time spent searching, pursuing, and handling food relate to the energy gained. The theory is a set of testable models rather than a claim that animals calculate anything; it describes patterns that natural selection can favour, and real animals frequently depart from its simplest predictions.

A useful distinction is between searching, capturing or collecting, and handling food. A strategy that excels at one stage may be costly at another: a fast pursuit can secure prey but burns energy, while sitting and waiting saves energy but risks long unproductive periods. Diet also shapes the picture, since herbivores, omnivores, and carnivores face different problems of finding, processing, and detoxifying food. Treating foraging as a balance of trade-offs, rather than a single talent, reflects how the literature frames it.

Among predators, two broad approaches are often contrasted. Ambush, or sit-and-wait, predation involves remaining concealed or stationary until prey comes within reach, then striking quickly. It is associated with low energy expenditure during searching and can pair with camouflage, but it depends on prey arriving and on a rapid capture. Animals frequently discussed as ambush foragers include many snakes, crocodilians, praying mantises, and trapdoor spiders, though species within these groups vary and some switch tactics depending on conditions.

Pursuit, or active, predation instead involves moving through the environment to locate and chase prey. It can cover more ground and exploit mobile food, but it typically costs more energy and may expose the forager to its own risks. Cheetahs, many canids, dragonflies, and tunas are commonly cited examples, again with substantial variation. The ambush-versus-pursuit contrast is best read as a continuum: numerous animals are intermediate, and the same individual may ambush in one setting and pursue in another. None of this is offered as tracking or hunting technique; it is a summary of how researchers categorise observed feeding behaviour.

Not all food acquisition involves capturing individual prey. Filter feeders strain large numbers of small organisms from water using specialised structures. Baleen whales such as the blue whale (Balaenoptera musculus) use plates of baleen to filter krill and small fish, while many bivalves, some sharks, and flamingos filter or sieve particles in their own ways. The shared theme is processing volume rather than pursuing single targets, which can be an efficient route to food where small organisms are abundant.

Grazing and browsing are the herbivore counterparts to this collecting mode. Grazers crop low vegetation and browsers take leaves, shoots, and fruit, and both must contend with plant defences and with the time needed to digest fibrous material. Because plant tissue is often low in readily available energy, many herbivores spend a large share of the day feeding and rely on gut microbes to break down cellulose. Describing these as foraging strategies underlines that finding and processing food is a problem for plant-eaters as much as for predators.

Some animals forage in groups, and in certain species this includes coordinated capture of prey. Cooperative hunting has been documented in particular populations of wolves, lions, African wild dogs, spotted hyenas, some dolphins, and Harris's hawks, among others. Studies describe behaviours such as encircling prey or pursuing in relays, and researchers debate how much of this reflects genuine role differentiation versus individuals each responding to the same situation. The careful position is that coordination is observed in studied groups, while the underlying cognition is still being investigated and should not be overstated.

Cooperative foraging need not mean deliberate teamwork. Mixed-species flocks and shoals can improve feeding for their members simply because more eyes find food or because one species flushes prey that another catches. It is also worth stressing that documenting cooperation in one population does not license sweeping claims about a whole species: behaviour can vary between regions, between social groups, and between wild and captive settings. Captive observations in particular may not generalise to the wild, a caution that applies across foraging research.

Scavenging, feeding on animals that died by other causes, is a widespread and ecologically important strategy rather than a marginal one. Vultures are highly specialised scavengers, but many animals usually thought of as predators, including lions, hyenas, and numerous birds, scavenge opportunistically when carrion is available. Scavengers contribute to nutrient cycling and to processing carcasses quickly, and some research suggests efficient scavenging may help limit how long carrion persists in an ecosystem, so the behaviour is significant beyond the individual meal.

A related tactic is kleptoparasitism, in which one animal takes food that another has caught or collected. Frigatebirds harassing other seabirds and skuas pirating fish are classic examples, and the behaviour appears across many groups. Like scavenging, kleptoparasitism reflects the energetic logic of foraging: taking already-acquired food can be cheaper than capturing it directly when the opportunity exists. These are descriptions of feeding ecology, not value judgements, and terms such as piracy are convenient labels rather than claims about motive or morality.

Caching, or hoarding, is the storage of food for later use, and it links foraging directly to memory and to seasonal ecology. Some corvids, such as certain jays and nutcrackers, and various rodents store large numbers of food items and recover many of them later. Experimental studies of food-storing birds have examined spatial memory and the hippocampus, and some work reports that individuals in these species can remember features of what was stored and where. How closely this resembles human-like episodic memory remains debated and is stated cautiously in the literature rather than asserted.

Caching has ecological consequences beyond the individual. Seeds that are stored and never retrieved can germinate, so scatter-hoarding animals can influence which plants spread, making them part of seed-dispersal systems. The behaviour also illustrates how foraging strategies often combine: a caching animal searches and handles food like any forager, but adds a storage stage that draws on memory and shapes its later movements. As with the other strategies here, these are observed patterns documented in particular species, not abilities that should be assumed across whole groups.

This guide is part of FaunaHub's animal intelligence & behavior cluster. For how these claims are sourced, see animal research sources, and for the biology behind behavior, see animal senses & adaptations.