Herbivores are animals that strictly eat food which is derived from living plant life including fruit, leaves, shoots, wood, etc. Being a herbivore is opposed to other diet descriptions such as fungivores which explicitly eat fungi, carnivores which explicitly eat meat or detritivores which eat dead cell matter.
There are many different types of herbivore though, which can be split into different categories if they tend to stick to diets stricter than just plant life, for example, frugivorous animals are a type of herbivore which prefers to eat fruit and will seek fruit above all else.
Types of Herbivore
Let us take a look at the 7 different feeding strategies of herbivores and the animals within these categories, maybe before reading you can even take a guess at what these different strict diet options that animals have might be and continue on to see if you are correct!
It’s important to note that an animal under these dietary classifications do not only eat that particular food item because all life needs a balanced diet according to their needs, but it is safe to safe that the focus of their eating habits will be of that particular food type.
As mentioned above, frugivores are animals which have a diet that primarily consists of fruit. They can be herbivorous or omnivorous depending on the species and its dietary requirements, you would be surprised at the flexibility of diets within the animal kingdom but ultimately, frugivores are highly dependent on fruiting plants and trees being present in their environment.
They also can be quite beneficial for the local environment, as sometimes the seeds are not digested or can resist the digestion process and are therefore dispersed. It has been theorized that plants evolved fleshy fruit to appeal to fruit eating animals as seed dispersal by the animal allows the young fruit bearing plant to germinate further away from the parents. This relationship is called mutualism.
Examples of Frugivorous animals have many bird species and also some mammals including:
The Cassowary is a large, flightless bird with three species. They are native to the islands of Australia, including the mainland. They are omnivores but will primarily eat fruit. Their beaks can open can wide and have a flexible esophagus which allows them to swallow fruit whole without the need to chew.
Toucans are also a frugivorous bird species and they have large bills which are used to crush fruit and deliver it to their throats for swallowing. They’re beautiful tropical birds with a vast array of vibrant coloration including on their bills. They’re arboreal birds which mean they live and nest primarily in trees.
An orangutan’s diet consists of 65% fruit. There are three species that are native to south Asia but unfortunately are only currently found in the wild in Borneo and Sumatra. They are known to be part of a family called the great apes and are the only known within this family to have a primarily arboreal lifestyle.
Also known as megabats or flying foxes, the fruit bats have a diet which largely consists of fruit. They are native to geographic locations that have tropical and subtropical environments including Oceania, Eurasia, and Africa. The term fruit bat refers to the family Pteropodidae of which there are many subfamilies and species within them.
The second category we’re looking at now is also the most obvious; folivores, or animals whose diet consists mostly of leafy green foods. These animals will usually have quite a specialized digestive system as this type of food is usually quite difficult to digest.
As a result, we have animals that are called ruminants, (like that of cows or kangaroos) those that have multiple stomachs used for fermenting the cellulose high foods. Not all folivores are ruminants of course but they do exist within this category.
It’s quite rare for folivory to be present in birds and there’s a good reason for this. They tend to have elongated digestive tracts due to the adaptation that’s needed to digest hard plant matter, it would prove quite cumbersome for a bird and affect its flight ability.
Folivory is, however, most commonly found in mammals:
Recognized for being particularly slow in their movement, with a greenish tinge to their fur due to the algae growth with they use to supplement their diets and their curved claws for gripping and climbing. Sloths are primarily folivores that live arboreal lifestyles, traversing the branches of the canopies of South American rainforests. Certain species of sloth such as Brown Throated Sloths are endangered due to the loss of habitat as a result of human activity.
One of the few bird folivores is the hoatzin or otherwise known as the stink bird which occupies the swamps and rainforests of the Amazon. It looks quite unique in its own right by looking quite similar to depictions of the ancient archaeopteryx. It features a large crop when compared to other birds of its size which is used for fermentation of its food in a similar way ruminant mammals do.
All species of caterpillar are folivores, spending their days consuming leaves in the vein of the hungry caterpillar form the kids’ book. They are the larvae of moths, butterflies and sawflies but not all caterpillars are even herbivores, there are very few species which seek to eat other insects and are even cannibalistic.
Algivores as you may have guessed have a diet that primarily consists of algae, and the majority that take on this type of diet are water dwelling creatures; mainly fish. Those who keep aquariums will know that algae can be a vital food source for their bottom dwelling pets and is essential for keeping the tank healthy.
A popular choice for those with aqueous pets, Ramshorn snails make great tank cleaning staff who never asks for payment. They are quite unique compared to their mollusk counterparts because their blood contains red hemoglobin like mammals as opposed to other snails that use green hemocyanin.
Rabbit Fish are another common choice for the saltwater aquarium due to their pretty vibrant coloration, their complex scale patterns and their preference for algae as a food source, keeping the tank a clean and healthy ecosystem. There are many different species of rabbitfish, some preferring solitary lives whilst others live in schools so make sure if you do make a purchase, choose one which is right for your aquarium.
Majidae is a family of crabs whose carapace is as long as it is wide. They usually are covered in bristles of varying shapes and sizes to which algae can attach and the crap can then feed on. They are also bottom feeders and patrol the ocean floor looking for algae or other food sources that they can find.
This may have been one which you didn’t guess. Nectarivores, as the name suggests are animals which feed on nectar, a highly product that plants use to attract feeders in hopes of spreading pollen. However, there are some species of animals which are effectively nectar thieves and never actually have the pollen attach to them, probably as it may affect their motility.
Being a nectar eater is not the best solution to food as even though nectar is great for providing carbohydrates and other minerals, there is very low protein content and so animals tend to be insects who use this feeding method only at particular stages in their life cycle.
Nectarivores are mainly insects and birds due to their ability to fly allowing them easier access to this food source.
Hummingbirds are fascinating as they have the ability to flap their wings at an exceedingly rapid pace. As a result of this, they actually use the majority of the energy obtained from the nectar as well as needing to excrete the water from they get from the nectar and have adapted very highly efficient kidneys.
There are many species of hummingbird, the majority of which sport beautiful metallic/iridescent coloration in their feathers. They are mainly found in tropical locations such as Central and South America, including the Caribbean.
There are so many insects which take on nectivory as their feeding strategy that it would be a huge task to mention them all. Most people think bees, in general, are great for pollination but the carpenter bee actually goes out of its way to avoid collecting pollen. Instead, they prefer to use an adapted proboscis to pierce their way into the reproductive organs of the plant and steal the nectar.
They swoop in and can shock you into thinking a wasp is trying to hassle you; hoverflies are prime examples of nectarivores. They only take to this diet in the adult stage of their lives and are insectivores whilst young and some species are actually highly regarded by farmers because their larvae actively target crop-damaging aphids.
These are the animals that prefer the consumption of seeds as their main food source, sometimes even as their only food source. Seeds become an attractive food source for animals as they have are a very concentrated source of nutrition compared to other parts of the plant which are what the plant uses to boost the germination of their offspring.
In fact, seed predation is a reason you find plants take up using natural defenses on their precious seeds either chemically or physically. Hard outer shells, spikes, and fuzz are all physical defenses whilst chemicals that are toxic such as cyanide or those that make the seed taste awful are the chemical defenses that plants employ. Others even have mucus-like layers over the seed which helps soil stick to the seed, therefor providing camouflage from hungry animals.
Birds are the usual suspects when it comes to granivory as they can cover a lot of ground through flight, swoop down and eat their fill and then move on again to find more. Some are particular about the type of seed that they choose whilst others aren’t fussy.
The sparrow is a family of birds called Passeridae which contains many different species. They are quite common across Europe, Africa, Asia, America, and Australia. They prefer to live in forests and open grasslands but are no stranger to suburban environments and are a type of bird which frequent garden bird feeders.
Eurasian tree sparrows and house sparrows are the most adapted two species to human environments and will even live in cities nesting and feeding in and around buildings. They can also be considered as pests when it comes to agriculture as they steal seeds planted by farmers but they can also be beneficial too by consuming pests of the insectoid nature.
Parrots and Parakeets
Small parrots are also granivores, preferring to chomp down on nuts and seeds. People will often buy seed mixes to feed their cockatiels for example but be warned, they will need other food options to supplement their diet and it’s a good idea to add a kibble for birds to mix into their seeds.
Doves and Pigeons
These birds make up the family Columbidae of which there are a good variety of species across the world. They are granivorous by nature and most of you who live out in suburban or rural Europe will have no doubt heard and seen wood pigeons grazing at bird feeders and on the ground.
Of course in the cities, urban pigeons flock together scavenging for food and absolutely love it when somebody spreads seeds over the ground for them. The zebra dove is a particularly pretty, wild species of pigeon which are known for the soothing sound they produce.
Most fowl and game birds such as quails, pheasants, chickens, and grouse have granivorous diets and even though you will find them foraging for juicy insects to supplement the protein in their diet, grain is the main order of every day for them.
Most game birds like to occupy grassy areas which keep them covered from predators whilst they graze and tend to roost in trees. Sandgrouse, in particular, is a species which migrates quite far just to look for water and put them at great risk just to quench their thirst.
Mucivores or Gummivores
A mucivore, otherwise known as a gummivore, is a name given to an animal which has a diet which is mainly constituted by plant sap. There are not many animals that have this feeding habit, as it requires specific adaptations which are designed to overcome tough plant defences and to also digest and process plant-based nutrients.
The main pests of the gardening world, aphids or otherwise known as blackflies or greenflies, are mucivorous and they use a specialized proboscis which pierces the stems and leaves of plants to suck up their sap. This is highly damaging to plants and an aphid infestation can quickly leave a sickly garden.
Fortunately for gardeners, aphids are a part of a healthy ecosystem and are predated by a great variety of insects. This includes certain species of ant, parasitic wasps, ladybugs, hoverfly, aphid midge larvae, and many more. So to all you gardeners out there, before you squish a bug ask yourself whether they actually help your garden to thrive.
Fork Marked Lemurs
Much less of a pest, the fork-marked lemurs are named so due to the black stripe that runs upwards from each eye to meet on the back of their neck and run down their back as a single stripe. They are the least studied group of lemur even though they are physiologically one of the most unique. As with every lemur species known, they are native to and only found in Madagascar and a huge conservation effort is put in place to protect them but despite this, habitat destruction is still prevalent.
Their diet consists of the gum of trees that exist within the rainforests in which they inhabit but they also supplement their diet by hunting insects much like the granivorous game birds do.
It’s quite certain many of you reading would not have thought of this one; if you did well done to you! Xylophages are animals whose diet consists of wood; sometimes wood is even the sole constituent of their diet. This is not to be confused with sapro-xylophages which feed on dead or rotting wood which is found more in the world of fungi.
It’s usually arthropods that are xylophagic, that is animals which are invertebrates and have segmented bodies; insects in other words. The digestion of wood is not an easy task for an animals digestive system alone and so many species that have this feeding strategy often have symbiotic gut bacteria to help them break down the cellulose.
Termites can be a bane to homeowners; costing them a great expense in either ridding their home of termites and/or replacing the damage the termites have dealt to the wooden structures in their home and furniture. As a result of their digestive process, they are considered a major source of atmospheric methane contributing to atmospheric greenhouse gasses.
Termites are actually very advanced creatures socially and are described as “eusocial” meaning that they have organized colonies which focus on the division of labor between different castes. Termites are found everywhere, on every continent except for Antarctica making them one of the most successful insect groups on earth alongside ants and flies.
People often call woodlouse “pill bugs” or “roly polys” which is a comment on their shape and the ability of some of them to be able to roll up into a defensive sphere, but not all species can do this. Most people also think of them as insects but whilst being arthropods they are actually terrestrial crustaceans.
Woodlice are very adaptable and can be found in quite extreme and unexpected environments for example; the species Hemilepistus reaumuri are found in the deserts and plains of North Africa which is the driest environment that a crustacean can be found in. On the contrary, Ligia oceanica is a species found in the shallow waters of seas all over the world!