Cows, like many other animals, can become infested with parasites such as ticks, fleas, and lice. These parasites feed on the blood of the cow and can cause irritation, infections, and even anemia if left untreated. Thankfully, some bird species have formed symbiotic relationships with cattle, providing pest control by feeding on these parasitic insects. This helps keep cattle healthy and parasite free. In this article, we will explore what types of birds eat parasites off cows and how this unique relationship benefits both bovid and bird.
What are some common cattle parasites?
Cattle can host both external and internal parasites. Some of the most common external parasites that infest cows and other livestock include:
Parasite | Description |
---|---|
Ticks | Ticks are arachnids that embed their mouths into the skin of the host and feed on blood. They can transmit diseases like anaplasmosis, babesiosis, and Lyme disease. Common species that affect cattle include the Lone Star tick, American dog tick, and Blacklegged tick. |
Lice | There are over 50 known species of lice that can infest cattle. They feed on skin and debris and can cause rubbing, scratching, and hide damage. Heavy lice infestations may lead to anemia. |
Mites | Mites like Chorioptic mange mites burrow into the skin and cause severe irritation. Infestations lead to rubbing, hair loss, and lesions on the legs and tailhead. |
Flies | Flies like stable flies and horn flies feed on cattle blood, while blow flies and screwworms feed on open wounds. They can transmit diseases and lead to reduced milk yields. |
Internal parasites like roundworms, flukes, and protozoa can also infect cows and hamper productivity. But these are not affected by the pest control birds provide. The external parasites are the target of birds that remove ticks, lice, mites, and other insects from cattle hide and coat.
Why are cattle susceptible to parasites?
Cattle are prone to parasitic infestations for several reasons:
- Their large body size and available surface area makes an ideal feeding ground.
- They live in close proximity, allowing parasites to easily spread among the herd.
- Thick hair coats give parasites ample space to hide and breed.
- Cattle graze close to the ground and brush up against vegetation where parasites live.
- Young and old cattle with weakened immunity are more susceptible.
- Warm climates allow parasites to thrive.
Heavily infested cattle exhibit signs like skin irritation, hair loss, reduced feeding, weight loss, and anemia. This leads to decreased meat and milk yields. Parasites can even kill cattle if populations explode and infestations become severe. That’s why efficient, natural parasite control offered by certain bird species is so important.
Birds that Eat Cattle Parasites
There are several bird species adept at finding and feasting on cattle parasites. The mutualism benefits the cows by removing pests and benefits the birds who get an easy meal. Here are some of the most common birds observed riding on cattle and gleaning parasites:
Cattle Egrets
Cattle egrets are a common sight in fields and pastures where livestock graze. These white herons have a symbiotic relationship with cattle and other grazing animals. The birds perch on the cow’s back and hunt for ticks, flies, and other insects disturbed by the animal’s movement.
Originally native to Africa, cattle egrets migrated to South America in the 1800s and reached North America by the 1950s. Their ability to adapt to agricultural lands and consume cattle pests helped them spread widely across the world.
Cattle egrets consume a variety of parasites including horn flies, stable flies, horseflies, deerflies, ticks, and mites. The exact composition depends on what infests the cattle most heavily. A cattle egret can consume hundreds of insects per day in its mutually beneficial relationship with livestock.
Oxpeckers
Found in Sub-Saharan Africa, oxpeckers have a strong symbiosis with cattle, antelope, rhinos, and other large mammals. The name “oxpecker” comes from their frequent association with cattle. But they perch on a variety of species to feast on parasites.
The yellow-billed oxpecker and red-billed oxpecker have specialized claws and chisel-like beaks adept at removing ticks from hide and coats. An oxpecker can devour over 200 ticks per day and over 12,000 ticks per year. Their efficiency in locating and removing ticks is believed to be 80-90%.
In Africa, oxpeckers even have a mutual relationship with rhinos. They perch atop the rhino’s back and keep it free of ticks, much to the advantage of this endangered megaherbivore. Besides ticks, oxpeckers eat mites, stable flies, tsetse flies and other pests harmful to wildlife and livestock.
Buffalo Birds
The red-billed oxpecker is also known as the “buffalo bird” for its symbiotic relationship with the African Cape buffalo. These birds ride atop buffalo and graze on ticks and flies embedded in their hide. A single bird can remove thousands of parasites each day.
African buffalo are a favorite prey of lions, and heavy tick infestations make them more susceptible to predators. By keeping buffalo free of these pests, oxpeckers help the animals avoid deadly diseases like anaplasmosis and remain fit to evade lions on the hunt.
Cowbirds
Cowbirds are songbirds endemic to North America. Species like the brown-headed cowbird don’t actually perch on cattle, but they do benefit from the insects stirred up by grazing livestock.
Cowbirds follow behind herds of cattle, bison and other animals to pick insects off the ground and low grass. Their diets consist of approximately 40% insects, including flies, beetles, and larvae associated with cattle habitats.
By controlling insect pests around livestock, cowbirds provide a valuable service and exhibit a commensal relationship with cattle and other grazers, even if they don’t directly glean parasites off their bodies.
Buff-breasted Sandpiper
The buff-breasted sandpiper is a tundra-breeding shorebird that migrates through North American grasslands during its yearly journeys between Arctic summer homes and South American wintering grounds. These migratory routes bring buff-breasted sandpipers into contact with grazing cattle herds.
Researchers have observed these sandpipers opportunistically foraging cattle dung pats for dung beetles and fly larvae. In doing so, they help control flies associated with cattle pastures during their brief migratory stopovers.
Fiscal Shrike
The fiscal shrike is an aggressive predatory songbird found throughout Sub-Saharan Africa. It has a unique hunting strategy that allows it to capitalize on insects stirred up by large grazers.
Fiscal shrikes will often perch on the backs of cattle, buffalo and other animals in search of disturbed parasites. From this elevated vantage point, the shrikes can spot and swoop down on unsuspecting insects landing on the ground below.
Research in one Kenya grassland found that fiscal shrikes increase their hunting efficiency by 17% when using cattle as hunting perches versus hunting from the grass alone. The cattle benefit by having the shrikes pick off flies, ticks and other pests as they move through pastures.
How Do Cattle React to These Birds?
Cattle appear tolerant or even welcoming of these symbiotic birds that help control their parasitic pests. Here are some observations of cattle responses:
- Cattle egrets are able to perch atop cows without startling or disturbing them, allowing the birds to leisurely hunt insects.
- Oxpeckers may be initiated into a herd by an older animal that seems to “teach” the value of their presence.
- Buffalo and cattle do not seem bothered by oxpeckers and make no effort to dislodge them.
- Cattle have been observed adopting a spread-legged stance which enables the birds to more easily access their underbelly.
- Cattle herds even appear apprehensive and agitated when their cleaning birds are absent for long periods.
These types of reactions suggest cattle understand the pest control service the birds provide. This makes the relationship more truly mutualistic versus simply commensal.
Do Cattle Receive Any Other Benefits?
Besides parasite removal, cattle may gain additional advantages from these symbiotic birds:
- Less rubbing, scratching and hide damage from reduced parasite load.
- Lower risks of diseases transmitted by flies, ticks and mites.
- Increased feeding time and weight gain with fewer insects to cause irritation.
- Higher milk production for dairy cows when flies and horn flies are controlled.
Potential increase in blood serum iron levels.
The iron benefit remains controversial but some research suggests oxpecker feeding may cause slight bleeding that increases iron availability to cattle herds prone to anemia.
Conclusion
Birds serve an important biological role in removing parasites from cattle and other livestock. Species like the cattle egret, oxpecker, buffalo bird, cowbird, and fiscal shrike all coexist mutualistically with cattle and provide pest control services.
In return, the birds gain an easy meal and productive hunting grounds by living near cattle and their pastures. Even migratory birds like buff-breasted sandpipers opportunistically pick beneficial insects from cattle dung.
Cattle appear tolerant and even welcoming of these parasite-eating birds. They gain health benefits including reduced irritation, disease risks, hide damage, weight loss and milk production decreases. This unique interspecies relationship highlights how birds and livestock can cooperatively thrive through symbiosis.