You may often see birds sitting on the backs of cattle or more exotic animals such as hippos. There are many reasons birds have this relationship with animals, but does it only benefit the bird or the animal?
Birds can often be seen around large mammals, and this is beneficial to both parties. Some birds will feed on ticks that attach themselves to a large animal’s body, while others will benefit from insects kicked up when an animal moves, especially through the dirt.
Birds can often be found around many animals. These include cattle, hippos, rhinos, zebras, wildebeest, and antelope. Although this behaviour is always initiated by the bird, this is a symbiotic relationship. Birds hang around animals because they can feed on them, either directly, as in the case of the oxpecker, or with insects that are kicked up when the animals walk, such as the way that starlings feed.
There are many different birds that can be seen around animals, and most large animals tolerate them. Out of all the large animals in Africa, only the elephant has no time for them, swatting them off with their trunks, ears, or tail.
Many birds will use their relationship with mammals to feed, but I have put just a few examples below.
Feeding on parasites
Oxpeckers Buphagus sp. gets their name from their habit of perching on large animals. However, this is not just ox, but also hippos, zebras, rhinos, giraffes, and cattle.
They feed on ticks and insects, as well as the mammal’s blood. Although this was once thought to be symbiotic, it is now seen to be much more parasitic. Oxpeckers often aggravate the wounds on animals which can inhibit healing. They will also feed on fly maggots and fluids from any wounds, but this may also lead to further wounds for the animal.
Oxpeckers do not have reversible toes but have the conventional three forward, one back toe. However, they are very agile and can be seen on top and hanging underneath large mammals. Their feet are curved and sharp, giving them a tight grip on hair or fur.
Oxpeckers use their tails to increase their stability while hanging on the sides of animals, using them as a prop. Red-billed oxpeckers have bills that are flattened on both sides and are used to work through their host’s fur, much like a comb. The bill moves rapidly, opening and closing quickly. They then use their bill as scissors once they find their prey, cutting the tick’s bodies in two. The heads are burrowed into the animal’s body, and they will dry up and fall off.
Yellow-billed oxpeckers have bulges at the base of the bill and a broader tip. They will grip their prey and pluck it off, which causes more of a wound to the mammal.
Oxpeckers have special claws which allow them to move about on fur or hides much easier, and their beaks and tails allow them to get around easily.
The association with mammals occurs as a regular habit in many bird species. Animals, when moving through their habitat, whether through dense undergrowth or through an open field, disturb insects and other prey that birds can feed on.
Feeding on insects
Animals often kick up dirt when they are moving, and this can also flush up many insects, which many birds will feed on. By following an animal or a herd of animals, birds can get more food than they would be able to if they were alone.
Cattle egrets get their name from their association with cattle but can also be seen around buffalo, zebra, and wildebeest. Unlike the oxpecker, they do not take ticks off the body, although they are sometimes called tick birds. The way that the cattle egret benefits from hanging around larger mammals are to get insects disturbed from the earth when they move. Their time spent with mammals allows cattle egrets to find food much more quickly than hunting alone.
The drongo Corvus balicassius is another African bird that can be seen sitting high on vegetation, waiting for insects kicked up by animals.
Other birds also show the same similarities. Starlings Sturnus vulgaris can often be found around on the ground around cattle, jumping in between their feet to feed on the insects dug up as the cattle moves.
This happens all over the world, with the pipiac Philostomus after often found around wild animals and grazing stock in Africa. They can often be seen on the backs of elephants, something that is not tolerated with other birds, such as the oxpecker Buphagus spp.
Hippos are another animal from Africa that many aquatic and wading birds will perch on the back of while submerged, with cormorants Phalacrocorax sp. being the most characteristic.
Sometimes perching on the back of a larger animal can be a resting place, while others use it as a great place to fish from, such as the hamerkop Scopus umbretta, which launches off to fish for frogs.
The common sandpiper Actitis hypoleucos can often be seen on the back of a hippo, but unlike the hamerkop or cormorants, the common sandpiper will feed on small invertebrates on the hippo.
It is not only large mammals that birds associate with but also smaller animals. Birds often party up with squirrels in tropical forests when the squirrels attack snakes. The birds usually feed on the insects, which the squirrel flushes out when attacking.
Hornbills Tropicranus albocristatus have spent so much time around guenon monkeys that they have evolved eyelashes. They will also follow them to eat any insects that they flush up as they move. However, they will also sometimes feed on small monkeys.
The common miner Geositta cunicularia is found in South America. The common miner will only nest in the burrow of another animal, a small chinchilla, the vizcacha.
Only birds ever initiate this behaviour, although it does also benefit the mammals. Birds will often get alerted to a potential predator faster and will fly away, alerting the animal to the nearby threat. By removing parasites such as fleas, lice, mites, and others, birds are an excellent addition for a large mammal to have around.
Although many large mammals use their tails as a fly swatter, many biting flies can carry diseases, and lots of bites can sometimes be fatal to even the fiercest creatures. Lions can sometimes be seen climbing trees to get away from them, and so the benefit of having an insect-eating bird around you is very handy.