Oxpecker birds (Buphagus erythrorhynchus), or more commonly known as the “tick birds”, are both very fascinating, yet confusing little creatures. Well known for being natives of the African continent, the oxpecker bird can be easily separated into two different distinct types of bird species: both the major species and focus species of the study being red-billed oxpecker bird (Buphagus erythrorhynchus) located in northern Africa and the other derived, sister species, being the yellow-billed oxpecker bird (Buphagus africanus) located in southern Africa (Stutterheim et al. , 2000). These two species of oxpecker birds differ not only in appearance and bill color, but also mating sound, preferences, and their habitat location (Stutterheim et al. , 2000). While both of the oxpecker bird species are known to be very talkative and interesting creatures, these birds are most commonly known for two reasons: 1. ) Their extraordinary and peculiar feeding habits and preferences. 2. ) Their invasive and unidentifiable relationships with their animal hosts.
Both species of the oxpecker bird differ slightly by their feeding habits, but mainly differing on what types of animals they choose to land upon and to be a host for their daily meals (Stutterheim et al. , 2000). The oxpecker bird has caused much conflict when it comes to its true relationships with animal hosts. It has been noticed to have both a mutualistic and parasitic relationships with the host they land upon (Stutterheim et al. , 2000).
With further exploration for information on this bird, we are able to determine what type of relationship is truly present in the oxpeckers daily interactions. The oxpecker bird spends most of its typical, normal day flying around and looking for a decently sized ungulate host to land upon or rest upon to begin its normal, everyday feeding process (Stutterheim et al. , 2000). Once the host animal has been located and the bird has landed, the oxpecker bird begins to remove and feast upon the invading ticks that are lingering on or are attached to the ungulates large body (Weeks, 2000).
The oxpecker birds will continue to remove the invading ticks with their bill until there are no longer any ticks present on the animal host (Weeks, 2000). If any nearby or oncoming predator is coming to attack the animal host and is sensed or noticed by the resting, feeding oxpecker bird, it immediately reacts to the predator’s presence and begins to fly away from its host (Plantan, 2009). This sudden motion of the
oxpecker bird ultimately sends a warning message to the unsuspecting ungulate host to either run away or to protect itself from the predator that is approaching (Plantan, 2009). This specific type of relationship is commonly known as mutualism. Mutualism is where both species benefits from the interaction with one another and neither are harmed in the process (Nunn et al. , 2011). In this case, the birds are being well fed while the animal host is rid of ticks and is able to avoid oncoming danger (Nunn et al. , 2011).
But the oxpecker bird is not always seen or known as the friendly, helpful companion it normally appears to be. While removing the invading ticks from ungulates body seems to be the oxpecker birds only job in life, the oxpecker bird will sometimes discard the removed ticks as its primary meal choice completely (Weeks, 2000) Instead, the oxpecker bird will use its bill to begin to pick apart and start eat the raw flesh remaining of the poor, unsuspecting ungulate it is currently resting and feeding upon (Weeks, 2000).
If no previously made wounds from invading tick removal can be found lingering on the animal’s body for the bird to feast upon, the oxpecker bird will use its bill and immediately begin to peck open and create fresh wounds on the body so they can start or continue on with their feeding process (Bishop and Bishop, 2014). This type of relationship is more commonly known as parasitism. Parasitism is where only one species benefits from the interaction while the other gains nothing in return and is harmed (Nunn et al. , 2011). In this case, the oxpecker bird is being well fed while the animal host is just experiencing pain (Nunn et al., 2011). These two interesting and different types of interactions can cause major confusion and conflict as to what type of relationship, parasitic or mutualistic, these oxpecker birds truly have with these ungulates hosts. Researchers have tried for many years to broaden their knowledge about this confusing and peculiar little bird. By monitoring and recording the daily lives and interactions of the oxpecker species and their hosts, experiments were able to be created and executed to discover what the oxpecker bird prefers as their primary meal source and whether or not it helps the animal hosts in the end.
Ultimately, these multiple experiments and observations will allow information on these birds to be pieced together and lead to discovery of whether the oxpecker and the ungulate hosts are considered to have a mutualistic relationship or a parasitic relationship. To dig deeper into this relationship mystery, individual experiments that were performed in different locations and that were executed in a different kind of way can be observed closer. Each of the experiments can hold information and conclusions for either a parasitic or mutualistic relationship.
The final results can then be compared to similar works to see if this information holds true for other experiments and if conclusions are similar in any way. If so, the collected information can either debunk or verify what conclusions are wrong and right. This will overall provide what type of relationship, or relationships the oxpecker actually has with its animal host. In order to do this, each type of relationship separately must be looked at separately and more viable information must be found on each that can either prove or disprove the experiments final outcomes.
The first experiment that was further evaluated was preformed back in 2004 at a local zoo located in northern Switzerland. This experiment will be a main focus, considering it shows perfect examples of both the parasitic and mutualistic types of oxpecker bird relationships. In this experiment, multiple rhinoceroses were placed in captivity and were relocated in two separate habitats within the zoo with a few oxpecker birds residing in each of the two separate habitats (McElligott et al. , 2004).
In one of the habitats, the captive rhinoceroses were completely exposed to invading ticks and all of the other outside insects and factors (McElligott et al. , 2004). The other habitat holding the other captive rhinoceroses in the study, however, were treated and cleaned of ticks or oncoming pests daily before they came in any contact with the oxpecker birds (McElligott et al. , 2004). The daily lives and interactions of all the rhinoceros, their responses to the oxpecker bird’s presence and their overall tick abundance in each of the habitats were observed and recorded daily over a twenty-one day period (McElligott et al, 2004). Knowing that oxpeckers feed primarily on ticks and other pestering insects, it would be assumed that the oxpecker bird would completely clean the infested rhinoceros of all of its natural pests and predators. However, this predicted outcome was not always the case for the tick infested rhinoceroses habitat. For most of this study, the oxpecker birds would use its bill to pick off and eat only the tick that were located on and removed from the ungulate host (McElligott et al. , 2004). But almost halfway through the study, the oxpeckers feeding preference outcome had begun to change for the worst (McElligott et al. , 2004).
The oxpecker birds would not only eat the ticks that they had been removing, but they also began to pick at the fresh, bleeding wounds that were left behind after the tick had been removed (McElligott et al. , 2004). The oxpecker bird’s newfound thirst for the host animals blood may be due to the fact that the tick meals are normally filled with the host animal’s blood before they are removed and eaten (Plantan, 2009). Therefore, the oxpecker birds acquired a taste for the animal’s blood through the tick and learned that they could obtain it by pecking and eating flesh straight from the animal’s body just as the ticks do (Plantan, 2009).
These new open wounds, however, are not good for the host animal’s health. The wounds are left open to potential diseases and other pathogenic outside factors that may ultimately be deathly to the animal host (McElligott et al. , 2004). Therefore, this information and these results lead closer to the idea of a parasitic relationship because the oxpeckers are being fed and nurtured while the rhinoceros are only being eaten alive. In comparison to this portion of the experiment, another similar experiment was done to measure overall tick abundance with the absence of the oxpecker birds.
Ticks were collected daily from the bodies of a herd of cattle in a field located in Zimbabwe (Weeks, 2000). The number of ticks that were collected from the cattle and the number of wounds the ticks had created were counted and recorded daily over a time span of one month (Weeks, 2000). The researchers then compared the absent oxpecker collected data to the data of the cattle that had been exposed to oxpecker birds (Weeks, 2000). The data of the cattle exposed to the oxpecker birds showed major differences to the oxpecker free cattle (Weeks, 2000).
The results of both parts of the experiment showed that there was no real significance in the number of invading ticks that were removed from the cattle, but there was a big difference between the number of wounds that were left in the cattle body (Weeks, 2000). This showed that the oxpeckers were not really focused on eating the ticks, but more interested in the blood of the cattle and therefore hurting it in the end (Weeks, 2000). The first experiment with rhinoceros shows both a mutualistic side and a parasitic side to the oxpecker bird.
In the presence of invading ticks, the oxpecker birds would eat the ticks as a primary meal but still began to create new wounds on the animal after a short period of time. This turned the oxpecker bird and rhinoceros’s relationship from being somewhat mutualistic to purely parasitic. In the second experiment comparison with the cattle, however, it was strictly a parasitic relationship between the two species. The cattle experiment debunks the empty conclusions that were missing from the rhinoceros experiment. This information shows that oxpecker birds really do not really have a preference for ticks as primary meals.
The oxpecker birds prefer and feed mostly on the flesh and blood of animals they are using as their host. This type of interaction between the two is not only harmful to the current animal host, but also can prove to be very dangerous and deadly as well when it comes to the overall health of the animal host. In order to enhance and push closer towards the idea of a parasitic relationship, a single oxpecker bird was put into captivity within a habitat with an ungulate and was monitored to see if they ate mainly ticks or flesh of the ungulate host (Milius, 2000).
The number of ticks that were removed and consumed by the oxpeckers and wounds that were fed upon and created were measured, recorded and monitored daily over a period of one month (Milius, 2000). Observations and recordings showed that invading ticks on the animal host body were chosen as a primary meal by the oxpecker birds 70% less then flesh or wounds of the animals were chosen (Milius, 2000). This shows that flesh was preferred more as a primary food source than the invading ticks.
This information leads more towards a parasitic relationship between the oxpeckers and their hosts. In the case of the cleansed rhinoceros habitat in the previously explained experiment, the outcome and overall conclusions were not that much different in results from the tick infested rhinoceros habitat (McElligott et al. , 2004). Since there were no invading ticks or other pestering insects available for the oxpecker birds to remove or feast upon from the host, they needed to find a new, viable food source to eat daily in order to survive (McElligott et al. , 2004).
The oxpecker birds would land upon the ungulates backs and since there were no invading ticks or flesh wounds currently present, they would begin to create new or fresh ones with their bill in order to begin their feeding process (McElligott et al. , 2004). The bird would peck and pull at the rhinoceros skin with their bill until they exposed tissue or caused blood to appear (McElligott et al. , 2004). The oxpecker birds would then feast upon whatever they had created or could get a hold of (McElligott et al. , 2004). The rhinoceros would try multiple times to shake the oxpeckers off of their bodies (McElligott et al. , 2004).
This technique, however, did not always prove to be helpful or useful for the animal host (McElligott et al. , 2004). The oxpecker birds would fly away from the animal’s body for a short time, but would then return once the shaking had subsided (McElligott et al. , 2004). In a similar experiment, the same technique was used but impala were used as the host animal instead of rhinoceroses (Mooring and Mundy, 2000). Oxpeckers were free to land upon the clean, captive impala as they pleased, and both the impala responses to this oxpecker bird’s presence and oxpeckers actions were recorded over a period of time (Mooring and Mundy, 2000).
The impala hosts did not mind the presence of the pestering oxpecker birds at first and would mostly just ignore their overall existence and intrusion as a whole (Mooring and Mundy, 2000). Without the presence of invading ticks as a primary meal, the oxpecker birds were forced to pick at old, scarred wounds (Mooring and Mundy, 2000). The oxpecker birds would then eat the flesh and blood of the impala host and would begin to create unnecessary new wounds on their skin if no previous ones were found (Mooring and Mundy, 2000).
The impala host did not agree to this kind of behavior and started to viciously shake their bodies in order to try and remove the pestering oxpecker birds (Mooring and Mundy, 2000). The oxpecker birds, however, would not let this attempt to shake them send them away (Mooring and Mundy, 2000). Eventually, the oxpeckers would return within minutes after the impalas shaking subsided (Mooring and Mundy, 2000). These few experiments showed that when the ticks were no longer a factor for a primary meal source, the oxpecker birds immediately went for the blood and flesh of theircurrent animal hosts. These experiments only portrayed a parasitic relationship between the two since the rhinoceros and impalas were only being harmed by the oxpecker birds and were not benefiting from them at all (Mooring and Mundy, 2000) (McElligott et al. , 2004). This suggests that the oxpecker birds may prefer to eat flesh in place of ticks because it is more appealing and appetizing to them. Both the rhinoceros and impala animal hosts did not tolerate the oxpecker bird’s invading behavior and tried constantly to shake the oxpeckers off or fight back, but they ultimately failed.
It shows that the animals did not want the oxpeckers to invade them and supports the idea of a parasitic relationship even more. In order to further enhance and verify the conclusions of all the experiments with parasitic outcomes, oxpecker birds should be placed in different cages with ticks and a piece of raw meat or animal flesh as primary meal choices. The oxpecker birds can then be studied and observed daily to determine what meal the oxpecker bird prefers to primarily eat over a period of time. This will determine if the oxpecker bird enjoys ticks for dinner or if they are truly blood driven creatures.
An experiment was done similar to this explanation to further prove that the oxpeckers wanted flesh and blood of host animals instead of ticks for meal source. Oxpecker birds were captured and were then separated into three different types of cages; one cage containing just a piece of flesh from a dead animal, one containing just ticks, and another containing both sources of food (Plantan et al. , 2009). The animals were given fresh, replacement food each day and their preference was recorded daily over a period of time (Plantan et al. , 2009).
In the first cage with both of the feeding preferences present, the animal host flesh was almost always preferred as the oxpecker birds primary food source while little to almost no ticks were feasted upon in the cage (Plantan et al. , 2009). The second cage with only animal host flesh present as a food source was almost always close to being all gone or was completely eaten by the end of the day (Plantan et al. , 2009). The third cage that contained only ticks for a food source were eaten scarcely by the oxpecker birds, mainly because that was the only food source present for the oxpecker to feast upon (Plantan et al., 2009). The results of this experiment show that the oxpecker birds preferred host animal flesh over ticks. Therefore, this shows that when the oxpecker birds land upon the animal hosts, they are not looking for invading ticks to feast upon (Plantan et al. , 2009). Instead, the birds are looking for wound in order to feed upon the animal’s flesh and blood. Regardless of all the biting and pestering done by the oxpecker birds in each of the experiments presented, the oxpecker birds also proved to be sometimes helpful and beneficial to their animal hosts when it came to the experiment referring to the rhinoceros habitats.
While removing invading ticks did not always seem like a positive interaction because of the flesh and wound eating that occurred after the tick was removed, there were also some positive results due to removing them from the rhinoceros body (McElligott et al. , 2004). The removing the ticks did stop most of the spread of diseases brought upon from the ticks from entering, overtaking and evidently killing the rhinoceros host that was being invaded by the tick (McElligott et al. , 2004). The survivability of the rhinoceros host also increased drastically when any potential diseases were no longer a health risk (McElligott et al., 2004). This suggested that the oxpeckers were actually helping the rhinoceros in some way, therefore giving evidence of a mutualistic relationship (McElligott et al. , 2004). To test if this is a true observation, another piece of work focusing on invading tick disease in wildlife was thoroughly examined to see if tick removal is truly beneficial to animal hosts (Bengis et al. , 2002). In this particular experiment, a large group of livestock was isolated into two different sections of a field (Bengis et al. , 2002).
One group of livestock was exposed to ticks and other pestering insects (Bengis et al. , 2002). The other group of livestock was clear of ticks and other potential pests daily (Bengis et al. , 2002). The livestock group without any tick or pest exposure was shown to have a 47% higher survivability rate than the livestock that was exposed any type of ticks (Bengis et al. , 2002). Any of the livestock that died during the course of the experiment were examined thoroughly to determine the cause of death (Bengis et al. , 2002).
The test results of the deceased livestock showed that the animal had been bitten by an infected tick that most likely transmitted the malignant disease over a period of time to the unsuspecting livestock host, which evidently killed the animal overall (Bengis et al. , 2002). Overall, these results showed that removing ticks would benefit the animal hosts by removing the infection before it began to spread (Bengis et al. , 2002). This information gives insight on the mutualistic relationships between oxpecker birds and their host animals.
The invading ticks however, were not the only substances that were being pecked at and removed from the rhinoceros hosts body and hair by the oxpecker birds (McElligott et al. , 2004). These oxpecker birds were also noted and observed removing and eating other types of pestering insects, such as flies, lice and fleas, from the rhinoceros hosts body and hair (McElligott et al. , 2004). The oxpecker birds were also sometimes seen feeding upon and picking at the loose dandruff and dry, dead skin that was present all over rhinoceros hosts body and hair (McElligott et al. , 2004).
The oxpecker birds were also sometimes observed removing, and discarding the compacted ear wax that was forming in the rhinoceros hosts ears (McElligott et al. , 2004). These other bodily removals by the oxpecker birds were overall helpful and beneficial to the rhinoceros hosts health and appearance, rather than causing more harm or damage to the rhinoceros (McElligott et al. , 2004). This proved to be a sign of a mutualistic relationship between the two since the oxpecker bird is not only being fed and the rhinoceros host is also being cleaned as well (McElligott et al. , 2004).
In a similar experiment, oxpecker birds were observed not only removing but also eating the earwax and dandruff off of other animal hosts such as giraffes, elephants, deer, zebras, etc. (Dickman, 1992). The earwax and dandruff from the animal host’s body provided protein to the oxpecker birds, benefitting their overall health and development (Dickman, 1992). The animal hosts benefit in two separate ways from this interaction with the oxpeckers (Dickman, 1992). The animal host’s ears are cleared of all of the earwax, meaning that they can detect and hear upcoming predators more easily than with their blocked ears (Dickman, 1992).
Also, the dandruff removal from the animal hosts hair and body helps prevent rashes or other irritations from developing on the animal hosts skin (Dickman, 1992). This type of removal and eating habit benefits both the animal host and the pest (the oxpecker bird) of the interaction (Dickman, 1992). Therefore, this experiment gives evidence of a possible mutualistic relationship between the two parties. In summary, all of the experiments presented for this topic represented one or both of the parasitic and mutualistic relationships of oxpeckers birds and their ungulate hosts. Each paper represented either a similar or an alternative experiment to other experiments. Their results either gave further support to or rejected the conclusions of the experiment all together. Both types of the oxpecker bird’s relationships were thoroughly investigated and proper examples of each type of relationship were provided. After many experiments and sometimes contrary results, it has been concluded that the oxpeckers have more a parasitic relationship with their ungulate hosts than a mutualistic relationship.
Many of the experiments presented for this topic showed the oxpecker birds in a state where they were only harming there animal host and not giving them any benefit at all (McElligott et al. , 2004). The oxpecker birds, however, should not be seen as only harmful creatures. Even though they seem to do more harm than good, they also tend to help their animal hosts with predators, spread of infection, and other overall health benefits (Bengis et al. , 2002) (McElligott et al. , 2004). This type of research on oxpecker birds is very important for future studies as well.
It is suggested that the oxpecker bird is currently on the verge of going extinct (Mellanby et al. , 2009). If the oxpecker bird is truly going extinct, it is suggested to be a positive thing to the ungulates since the oxpeckers will no longer be invaded and attacked by these animals (Mellanby et al. , 2009). Their extinction, however, can also prove to be very dangerous as well. While it would prevent animal hosts from being practically eaten alive, the overall health of these animal hosts will be in jeopardy because the oxpeckers will not be able to warn hosts of predators or stop the spread of infection (Mellanby et al. , 2009). The oxpeckers birds may be considered a parasite, but it does not mean that these birds are not needed in the environment. These birds help in more ways than are known and they should not be seen as just a threat to their hosts. Their extinction should be monitored more carefully so this species does not disappear altogether. Without this species, it is unknown what may truly happen to the animals that the oxpecker birds interact with on a daily basis. The oxpeckers should always be given the benefit of the doubt because we never know what may arise if this creature just disappeared one day.