Reliability of a New Method to Census Japanese Macaques Fixed Observers in Quadrats

Oi, Toru; Yoshihiro, Shinichi; Higashi, Hideo; Tezuka, Makito; Azuma, Shigeru

doi:10.2354/psj.10.77

Cited by 4 publications

(4 citation statements)

References 6 publications

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“…Traditional census methods, such as line transects, were difficult to conduct because of steep mountains and dense vegetation. Instead, I modified the “fixed observers in quadrats (FOIQ)” method devised by Oi et al ( 1994 ) by dividing the research area into 500 m × 500 m quadrats, with observers positioned at a fixed point in each quadrat. Four observers participated in one party covering an area of 1 km 2 with one leader.…”

Section: Yakushima Macaquesmentioning

confidence: 99%

My studies of primates: Sex, affinity, and competition

Takahata

2023

Primates

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In this essay, I summarize my research career, with reference to the early days of the Laboratory of Physical Anthropology (LPA) at Kyoto University led by Kinji Imanishi and Junichiro Itani. When I started conducting research on the sexual behavior of Japanese macaques in 1975, I made some unexpected observations. High-ranking males did not obtain high mating success. Estrous females often rejected the courtships of high-ranking males and chose to mate with lower-ranking males. Some male–female dyads exhibited long-lasting affinitive relations, but they avoided mating. Females frequently showed ‘excessive’ sexuality. Clear explanations for some of these observations do not exist. After that, I changed my study subjects several times from chimpanzees, Yakushima macaques (a subspecies of Japanese macaque), and ringtailed lemurs. It is difficult to summarize my findings into a consistent story. Instead, I review my research and experiences. Throughout my career, I kept two things in mind. The first was established by Imanishi at the Laboratory of Physical Anthropology at Kyoto University: to explore the evolution of human society. Second, I tried to understand seemingly incomprehensible phenomena using evolutionary theory. Despite adhering to these foundational concepts, things did not always work out as planned.

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Section: Yakushima Macaquesmentioning

confidence: 99%

My studies of primates: Sex, affinity, and competition

Takahata

2023

Primates

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“…However, this method is not applicable to populations whose mountainous habitats preclude the use of long, straight transects. For example, Japanese macaques (Macaca fuscata), as well as many other macaques in temperate regions, have never been censused by the line-transect method [Oi et al, 1994]. Most of the density data on Japanese macaques have been derived from intensive studies [e.g., Takasaki, 1981].…”

Section: Introductionmentioning

confidence: 99%

“…We used this method on Japanese macaques in Yakushima. The design of the census in this study is the same as that used in Oi et al [1994]; however, our work is original because we devised a procedure for estimating group density based on a statistical model, and examined various factors that might influence detectability. We examine the validity of our new method by comparing the results with the density values calculated by home-range data.…”

Section: Introductionmentioning

confidence: 99%

New method to census primate groups: Estimating group density of Japanese macaques by point census

Hanya

Yoshihiro

Zamma

et al. 2003

American J Primatol

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We devised a new method to estimate the density of primate groups in habitats that preclude the use of a line-transect census because the ground is too steep. We combined point census and group follows. From the number of groups counted at a fixed point for an hour, n, group density D was calculated: D = lambda n / pi. Lambda, the detectability constant, was a constant when distance-dependent detectability g(y) was regressed on a half-normal model: g(y) = e (-lambda y(2)) and can be estimated by combining the information of group follow and point census. Using this method, we estimated the group density of Japanese macaques in Yakushima. A census area of 7 km(2) was divided into 28 grid squares (500 m x 500 m). One observer was positioned at a point in each grid square, and those points were censused simultaneously for 4-6 days from 0600-0700 to 1500-1600 hr. Four troops were followed for 144 hr during the point census. Distance-dependent detectability closely correlated with the half-normal model. The detectability constant varied with the time of day, but it was not influenced by troop identity or topography. Group density was calculated to be 1.48 +/- 0.61 and 0.701 +/- 0.432 groups/km(2) in the disturbed and undisturbed areas, respectively (95% confidence limit). "True" group density estimated by home range data was within the confidence limit calculated by a point census in the home range of the troops for two troops, suggesting that this method was valid. This method is applicable to other species as long as at least one group can be followed, because it satisfies the fundamental assumptions of point census, and the detectability does not seem to be biased by troop or topography.

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“…1), in order to evaluate the reliability of a new census method, the 'fixed observers in quadrat (FOIQ) method' (see CENSUS METHOD for details). It was concluded that the FOIQ method could be successfully used in steep mountainous areas to produce sufficiently accurate estimates of macaque populations (Oi et at., 1994).…”

Section: Introductionmentioning

confidence: 99%