They went on to argue that this demonstrates the oxpecker's role in tick control. They artificially infested two oxen with a known number of adult ticks of different species and put them in a pen with five red-billed oxpeckers.Yet their result indicates only that impalas are better at reducing their own tick loads than are oxpeckers, which they achieve by grooming themselves with their teeth, a behavior shown to be extremely effective at reducing tick loads (Mooring et al., 1996). The birds significantly reduced the tick loads over a period of 7 days.Tags: Apa Research Paper SubheadingsAsthma Research PaperOrwell Essay On Making TeaSchool Life Memories EssayWhat To Write In A Scholarship EssayEssay On If I Were Given Three WishesThesis Binding NottinghamAccenture Case Study CompetitionInformal Letter Essay About HealthFree 10 Page Research Paper
Yet evidence for beneficial tick reduction is usually either anecdotal (Pitman, 1956), or inferred (Breitwisch, 1992; Someren, 1951).
Mooring and Mundy (1996), for instance, showed that the congeneric yellow-billed oxpeckers () feed on those areas of an impala where the animal cannot groom itself (head, neck, and ears), and that these areas have significantly heavier tick loads than the rest of the body.
Ticks are costly parasites because they drain blood, inflict bites, and are vectors for many diseases (Howell et al., 1978).
It is thought that tick removal must be beneficial to the host mammals, and the relationship between oxpecker and mammal is therefore believed to be a mutualism (Bezuidenhout and Stutterheim, 1980; Moreau, 1933; Mundy, 1992; Someren, 1951).
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.g., Randolph, 1994, 1997) and the congeneric red-legged tick (Yassir et al., 1992), and is considerably longer for the other species (Norval et al., 1992; Petney et al., 1987; Rechav, 1982).
For the experiment, I arbitrarily divided the herd into 2 groups of 11 animals, experimentals and controls.
For the first treatment (21 November-18 December 1996), I 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.