We tested the success rate and accuracy of GPS collar positioning for a free-ranging Japanese macaque. The orientation of the GPS unit, behavior of subject monkey and environmental conditions during positioning attempts were videotaped, in order to examine the factors affecting success rate and accuracy. Total positioning success rate was 38 % (54 success in 142 trials). Orientation of the collar GPS unit primarily influenced the positioning success rate. Success rate was 81 % when the collar GPS unit was oriented above or horizontal to the gravity, while all positioning attemps failed when the collar GPS unit was oriented downward. Vegetation also affected the success rate. Success rate was lower in the evergreen broad-leaved forest than those in the feeding site, grassland and defoliated broad-leaved forest. Orientation of the GPS unit was not seriously affected by positional behavior of the monkey. Frequent manipulation of the GPS collar by the subject monkey caused the changes in the relative position of the GPS unit around the neck (dorsal, ventral or side). On the other hand, other monkeys did not touch the collar. We conducted positioning by handheld GPS (Garmin GPS V) at the same time and place of each GPS collar positioning attempt. The difference between coordinate values of the GPS collar and that of the handheld GPS was 13.2 m on average, suggesting that the accuracy of the GPS collar is comparable to that of a handheld GPS. Effect of vegetation on the difference between coordinates recorded by the GPS collar and by the handheld GPS was not detected. The results clearly indicate that the orientation of the GPS unit is of primary importance to achieve higher success rate in GPS telemetry. In applying GPS telemetry to primate research, measures to stabilize the GPS orientation to upwards, no matter how hard the animal manipulates the GPS collar, must be considered.

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The evolutionary history of cercopithecine monkeys in the Eurasian continent is discussed based on the compiled chronological and geographic data of fossil records from the late Miocene through the middle Pleistocene. Cercopithecines are likely to have originated in northern Africa and appeared in Eurasia as early as the latest Miocene. The fossil records of cercopithecines are rich in Europe and Eastern Asia, where cercopithecines appeared at the latest Miocene. In both areas, respectively, there are three cercopithecine genera reported so far: Macaca, Paradolichopithecus, and Theropithecus in Europe, and Macaca, Procynocephalus, Theropithecus in Eastern Asia. All European fossil macaques are referred to the single species, M. sylvanus or to its close relative, whereas many species are recognized for the Asian macaques. This taxonomic contrast may reflect the geographical differences between the two areas: contrary to the relatively continuous land condition in Europe, Eastern Asia, especially Southeast Asia, has been fractionized into small islands or regions many times due to the eustatic change in sea level, which accelerated speciation of Asian macaques. On the other hand, it is also a debatable issue whether baboons have invaded Eurasia as well as geladas. It has been suggested by a Russian researcher that “Paradolichopithecus” sushkini of the late Pliocene of Kuruk-Say, Tajikistan, is not a macaque but a baboon based on the craniodental morphology (Maschenko, 1994; 2005), which was recently supported by CT (computer tomography) analysis on the structure of the maxillary sinus (Nishimura et al., in prep.). Evolutionary history of cercopithecine monkeys may be more complicated than ever presumed.

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