What animals eat

Biologists classify animals by their primary food source because diet links every species to the wider ecosystem. A feeding category describes where an animal tends to sit in the flow of energy - from plants, to plant-eaters, to the animals that eat them, and finally to the organisms that break down what remains. These groupings are generalisations, and many real animals blur the lines or shift between categories over a lifetime.

Diet varies by species, and also by age, season, and habitat. A juvenile may eat very differently from an adult, dry-season foods may differ from wet-season foods, and the same species can feed differently across its range. Because of this variation, the categories below describe broad natural patterns rather than fixed rules, and certainly not instructions for feeding any individual animal.

Herbivores eat plant material, and ecologists often split them by what part of the plant they target. Grazers, such as many cattle relatives, zebras, and geese, feed mainly on grasses and low ground vegetation. Browsers, such as giraffes, many deer, and black rhinoceroses (Diceros bicornis), feed on leaves, twigs, shoots, and fruit from shrubs and trees. Some species do both depending on what is available.

Plant material is bulky and hard to digest, so herbivores have evolved specialised digestive systems - multi-chambered stomachs in ruminants, or enlarged hindguts in animals like horses and rabbits, where microbes ferment fibre. Rabbits (Oryctolagus cuniculus), for example, are hindgut-fermenting herbivores whose biology depends on a high-fibre intake. This is general biology, not a feeding instruction; the practical diet of any rabbit in human care is a question for a veterinarian.

Grazing and browsing shape whole landscapes. By cropping grasses, trampling, and selectively eating certain plants, large herbivores can keep grasslands open, influence which plant species dominate, and create the mosaic of habitats that other animals depend on.

Carnivores eat other animals. They range from big cats and wolves to weasels, and many have adaptations for hunting such as sharp teeth, claws, or keen senses. As a point of general biology, cats are obligate carnivores, meaning their bodies are adapted to a diet based on animal tissue rather than plants - again a statement about feline biology, not a feeding plan for any cat. Predators help regulate the numbers of the animals they hunt and can influence the behaviour and distribution of prey across a landscape.

Omnivores, including bears, pigs, raccoons, and humans, eat a mix of plant and animal foods, which lets them adjust to what is seasonally available. Insectivores specialise in insects and other invertebrates; anteaters, many bats, shrews, and countless birds fall here, and by consuming vast numbers of insects they play a major role in controlling invertebrate populations.

Bird diets are a clear reminder that categories vary enormously by species. A parrot, a chicken, a duck, and a hummingbird have very different natural diets, so there is no single bird diet. Reptile and amphibian diets vary just as radically from one species to another. These differences are biological facts about wild animals, not a guide to feeding any animal in human care - which always warrants species-specific veterinary input, including from an avian or reptile and amphibian vet where relevant.

Some animals exploit very specialised food sources. Nectar feeders such as hummingbirds, sunbirds, many bats, and countless insects drink the sugary nectar of flowers. In doing so they transfer pollen between plants, making them essential pollinators that help many flowering plants reproduce.

Filter feeders strain small food particles from water. Baleen whales, many bivalve molluscs, flamingos, and some fish capture plankton or tiny organisms in large volumes, linking the smallest members of aquatic food webs to some of the largest animals on Earth. By filtering water, animals like mussels and oysters can also influence water clarity in their habitats.

Detritivores and scavengers feed on dead material and waste. Earthworms, dung beetles, vultures, and many crabs and insects consume carrion, droppings, and decaying plant matter. Together with fungi and bacteria, they recycle nutrients back into soil and water, an unglamorous but vital service that keeps ecosystems functioning. Many animals also disperse seeds - by eating fruit and depositing seeds elsewhere, frugivores help plants spread and forests regenerate.

It is tempting to assume that whatever an animal eats in the wild must be exactly what it needs in human care, but that reasoning can be misleading. Wild animals select from a changing buffet, balance their intake over time, travel to find foods, and are subject to natural selection that removes those who fare poorly. An animal under human care lives in very different circumstances, and its individual needs depend on its species, age, health, and life stage.

For that reason, this page does not provide feeding plans, portion sizes, schedules, recipes, or supplement guidance for any animal, and it is not a substitute for professional care. Decisions about feeding a specific pet or captive animal belong with a qualified veterinarian who can account for that individual's needs. Never delay or avoid veterinary care based on general ecology information like this.

A natural diet does not mean every food is safe, and some everyday human foods are documented concerns for certain pets. As examples to discuss with a veterinarian - not a complete list and not emergency guidance - chocolate, grapes and raisins, xylitol, and onions and garlic are widely documented concerns in dogs, while lilies and onions and garlic are documented concerns in cats. No food is safe for all animals, and these are simply topics to raise with a professional, with no amounts, symptoms, or treatments implied here.

If you are ever worried that an animal has eaten something harmful, this is not the place for answers: contact a veterinarian, an animal poison-control service, or a local emergency service immediately. For any feeding or health question about a specific animal, consult a qualified veterinarian, including an avian or reptile and amphibian vet where appropriate.

Feeding wild animals deserves special caution. Even well-meant feeding can alter natural behaviour, create dependency, spread disease, crowd animals together unnaturally, fuel human-wildlife conflict, and provide poor nutrition or dangerous habituation. For these reasons this page gives no instructions on what or how to feed wildlife; if you have concerns about a wild animal, contact your local or official wildlife agency for guidance.