Feeding preferences of Oxpeckers in Kruger National Park, South Africa
In addition, impala (Aepyceros melampus) were found We studied the relationship between red-billed oxpeckers and black rhinos. (Diceros bicornis) in . were small and only slightly larger than the tips of the beaks. We could measure the. Red Billed Oxpecker and Impala The red billed oxpecker eats ticks on the from EDUC Humans and Commensalism • What are some commensal relationships . PDF | In order to better understand the symbiotic relationship of the interactions between yellow-billed oxpeckers (Buphagus africanus) and impala (Aepyceros Impala hosts tolerated oxpeckers 86% of the time, and 42% of .. red-billed oxpeckers Conflict, cheats and the persistence of symbioses.
Oxpeckers – Heroes or villains?
Furthermore, Koenig did not find any marked differences in the host species preferences of Red-billed Oxpeckers when comparing between areas of sympatry and areas of allopatry. Perhaps these differences between the Kenya study and the KNP findings could be attributed to differences in ungulate densities between the two sites. One would assume that the Kenya sites Masai Mara Reserve and Lake Nakuru National Park had a high abundance of large ungulates compared to KNP, hence a marked host preference would only be apparent in lower ungulate densities where interspecific competition is unavoidable.
However, that hypothesis cannot be tested without a measure of ungulate densities from all sites. Surprisingly, the PI results in the present study differed from Grobler and Stutterheim and Stutterheim Optimal foraging strategy Pyke will predict that animals will concentrate on the most abundant and profitable food source.
For example, there were fewer White Rhinoceros and Hippopotamus in KNP in the s compared to the present-day population It is therefore reasonable to conclude that as White Rhinoceros and Hippopotamus numbers increased, Red-billed Oxpeckers responded by selecting for these new abundant host species with potentially higher tick loads and less hair to hide the ticks.
Giraffe remained the most preferred host species in both the northern and southern regions of the park. This could also be a detection bias, given that it is possibly easier for flying birds to detect Giraffe compared to other shorter species. This is further supported by Oxpeckers' preference for White Rhinoceros and Hippopotamus both large ungulatesrecorded as host species in Skukuza.
Interestingly, Impala, an abundant, small-sized ungulate, was less preferred as a host species across studies. This surprising contradicts what has been reported by GroblerStutterheim and Stutterheim and Hart et al. Both Red-billed and Yellow-billed Oxpeckers displayed a preference for the back and head regions of their respective host species.
Red-billed Oxpeckers also preferred the necks of Giraffe. Additionally, Oxpeckers prefer feeding on the back regions of a host species since this is easily accessible and provides a stable perch Weeks Small groups of oxpeckers continued to visit and feed on the oxen in the field throughout the day Weeks, Cattle are hosts to five species of ixodid tick at Sentinel blue ticks, brown ear ticks, bont ticks Amblyommma hebraeum, red-legged ticks Rhipicephalus evertsi, and bont-legged ticks Hyalomma marginatum.
Ticks have three life stages larva, nymph, and adulteach of which requires a different individual host on which they attach and engorge with blood before dropping off and metamorphosing to the next stage. The exception is the one-host blue tick, which goes through its entire life cycle a process that takes roughly 4 weeks on a single host.
Adult male ticks of all species spend up to a month attached to their host; adult females are attached for about 1 week. For the experiment, I arbitrarily divided the herd into 2 groups of 11 animals, experimentals and controls. For the first treatment 21 November DecemberI excluded oxpeckers from the experimental group for 4 weeks. Because adult ticks are continuously attaching to the hosts and their drop-off rate is low, this period would have been sufficient to detect any effect oxpeckers might have had on tick loads.
An assistant stayed with the herd throughout the day oxpeckers do not feed during the night and chased off any oxpeckers that attempted to land on the oxen. I remained with the control group, which oxpeckers continued to visit and feed on as normal.
The two groups fed in two separate grazing areas, which I alternated every 2 days. They spent the night in separate cattle kraals, which I alternated every week. Controlling for grazing areas was particularly important because the ranch has large populations of other potential tick hosts, notably impala Aepyceros melampuseland Taurotragus oryxkudu Tragelaphus strepsicerosand warthog Phacochoerus aethipicus.
The density of ticks may therefore have varied from area to area. It is also important to note that the developmental period needed for engorged nymphal ticks to change into adult ticks is close to 2 months for brown ear ticks see, e. This does not take into account the additional time required for the adult's cuticle to harden, the tick to start searching for a new host, and the delay while it finds a host.
There was thus no danger of the results being confounded by cross-contamination between control and experimental herds.
Symbiotic relationship - the impala and the oxpecker by AccordingToJess - egauteng.info
For the second treatment 17 January FebruaryI switched the groups so that the experimentals became controls and vice versa. For the third treatment 19 August SeptemberI arbitrarily selected a different combination of oxen to fill the control and experimental groups. Although there were originally 22 oxen, 3 animals died during the year, so the sample size varies slightly between experiments.
For each animal, I counted all the adult ticks, identifying them to species level, and, for the bont ticks Ambylomma hebraeumto sex. I also assigned an earwax score based on a visual assessment of the inner portion of the right ear using the following scale: I repeated full tick counts, wound scores, and earwax measures on all animals every week.
Leave a reply It seems as though the jury is still out on whether the oxpecker is a hero or a villain. It is true that the oxpecker scavenges ticks off a wide variety of the larger African mammals, which is probably a good thing, but it also picks at any wounds or sores on the host animal to keep them open and bleeding, which is probably a bad thing. Indeed, the favourite food of the oxpecker is blood.
Many of the ticks that it feeds on are engorged females, which have already fed on the blood of the host animal, and have therefore already caused whatever harm they are likely to cause in terms of drinking blood and spreading disease. Too late to help the host, but great for the oxpecker! The open wounds also provide access to all manner of infections.