Red billed oxpecker and impala relationship test

Symbiotic relationship - the impala and the oxpecker by AccordingToJess - pugliablog.info

Oct 9, Request PDF on ResearchGate | Interactions between impala and oxpeckers at understand the symbiotic relationship of the oxpecker-mammal association and used in Tanzania do not contain The logistic regression tested the likelihood of a . Red-billed Oxpeckers, Buphagus erythrorhynchus, and. Red-billed Oxpeckers, Buphagus erythrorhynchus, and Yellow-billed Oxpeckers, B. africanus, are known to take part in symbiotic relationships with African Impala (Aepyceros melampus) are the exception to this generalisation since they are . Chi-square tests were then used to compare preference index distributions . Jul 14, The red-billed oxpecker and the mammals roaming the plains have a mutually beneficial relationship in which the birds feed on ticks and other.

The work was carried out in the lowveld of southern Zimbabwe on red-billed oxpeckers and a small herd of domestic cattle. Sentinel Ranch has a large population of red-billed oxpeckers that feed both on game and a study herd of 22 Bonsmara oxen the Bonsmara is a South African variety of cow, a cross between Bos taurus and Bos indicus.

Up to 60 individual birds visited the kraal cattle enclosure every morning, where they would spend approximately 2 h feeding on the animals.

Feeding preferences of Oxpeckers in Kruger National Park, South Africa

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.

Red-billed oxpecker

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.

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.

I only scored adult ticks, as there is no valid technique for counting larval ticks on a live animal Mooring and McKenzie,and it is difficult and time consuming to look for nymphal ticks. Adults are also accurate gauges of the overall tick load of an animal Mooring and McKenzie, With all the tick analyses, therefore, I analyzed not only the overall changes in totals, but also the changes in species' totals.

I compared the median monthly change in tick loads between experimental and control oxen for each treatment and corrected for this multiple comparison with a sequential Bonferroni correction Sokal and Rohlf, Because the data are not normally distributed, all my tests are nonparametric Siegel and Castellan, All statistical tests are two-tailed with the significance level set at 0.

Absence of oxpeckers also had little effect on infestation changes at the level of species and sex.

Mutualism: Oxpecker & Impala. Симбиоз: Волоклюй и импала (1379sp)

Blue ticks did not appear in any of the three replicates, and brown ear ticks, a seasonal species, only appeared in the second. Of these 16 remaining results, only 1 showed a significantly greater increase on experimental oxen Figure 2. Red-billed Oxpeckers appear to be limited to medium and small-sized ungulates, such as Kudu and Impala, in the northern parts of KNP.

This is most likely because of a home range overlap with Yellow-billed Oxpeckers, resulting in interspecific competition Koenig The larger in terms of body size Yellow-billed Oxpecker is territorial and capable of outcompeting the smaller Red-billed Oxpecker Hall-Martinpermitting the former a preferential choice of ungulates.

The study also shows that Red-billed Oxpeckers in the southern regions of KNP utilised the preferred large ungulates in the absence of Yellow-billed Oxpeckers, whereas their preference shifted to smaller ungulates in the presence of Yellow-billed Oxpeckers.

This further supports the notion of interspecific competition between Red-billed and Yellow-billed Oxpeckers for access to larger ungulate hosts. Contrary to the results from the present study, Hustler and Koenig in Zimbabwe and Kenya respectively did not find any differences in host ungulate preferences when both species occurred within the same geographic region.

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.

Red-billed oxpeckers: vampires or tickbirds? | Behavioral Ecology | Oxford Academic

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 The head is also preferred since it provides additional food resources other than ticks, i.

Exceedingly low occurrences of wound feeding by Red-billed Oxpeckers and the absence of wound feeding in Yellow-billed Oxpeckers suggests that this feeding behaviour is not prevalent in KNP as previously reported in cattle ranches in Zimbabwe Weeks Plantanin her study on both Oxpecker species at Shingwedzi inalso found the prevalence of wound feeding behaviour to be very low 3.