ABSTRACT We investigated the bodily mass of infants and postpartum adult females longitudinally i... more ABSTRACT We investigated the bodily mass of infants and postpartum adult females longitudinally in provisioned free-ranging Japanese macaque (Macaca fuscata) troops of the Takasakiyama Natural Zoo, Oita, Japan. We investigated whether the rate of mass change in postpartum adult females and infants is more strongly associated with season (or calendar date) as opposed to the length of time since delivery/birth. Focal adult females' postpartum mass ranged between 7 and 10 kg for a year after delivery. For postpartum adult females, calender date (season) influenced the rate of mass change more than the length of time since delivery did. Rate of mass change in postpartum adult females was high in October (autumn) and April and May (spring) and low between December and February (winter). This may reflect seasonality in energy and protein intake from natural foods. Infant mass increased steadily from birth. Mass of infants varied between individuals, some infants reached 2 kg by about 240 days of age, and others by about 400 days of age. It was unclear, however, whether the rate of mass change in infants was influenced more by age or calendar date (season). Differences in trends between adult females and infants may reflect, to some degree, differences in sources of energy intake, i.e. solid foods for adult females and suckling and solid foods for infants.
In a wild-living, artificially provisioned population of Japanese macaques at Takasakiyama in sou... more In a wild-living, artificially provisioned population of Japanese macaques at Takasakiyama in southern Japan, nine sets of twins were recorded from 12,392 known deliveries over a 56-year study period. Recorded twinning frequency was 0.073%. During the first 28-year period, artificial food was given until macaques were satiated and population size increased rapidly. In the second 28-year period, provisioned food was restricted to about half of the former period's calorific content. Seven sets of twins were born in the first period and two sets in the second. Twining frequency in the two periods was 0.137 and 0.027%, respectively. In comparing studies of other Catarrhine primate samples, we hypothesize that twinning frequency is influenced by living conditions, and we suggest that living conditions should be carefully evaluated in studies of twinning frequency.
From the late 1960s to the early 1970s, many congenitally malformed infants were born into provis... more From the late 1960s to the early 1970s, many congenitally malformed infants were born into provisioned Japanese macaque troops. Although the exact cause of this problem was not determined, the occurrence of malformations decreased thereafter. We examined possible factors such as total population size, number of adult females, birth rate, and volume of provisioned food. Agrichemicals attached to provisioned food are suspected as the main cause, as other factors were found to have no influence. Many more malformations were seen in males compared with females, in feet compared with hands, and in the fourth compared with other digits. We confirmed that the frequency of congenital malformation was high during the 1960s through to the mid-1970s when increased levels of provisioned food were given and that the incidence of congenital malformations was also elevated among wild macaques during this time.
Sex differences in infant mortality in provisioned Japanese macaque populations were examined usi... more Sex differences in infant mortality in provisioned Japanese macaque populations were examined using 10 data sets from five populations. The results indicate that there was no available data set in which a sex difference in infant mortality was statistically significant. To examine whether the observed sex ratios in infant mortality rates could be the product of stochastic variation in small samples, a correlation between sample size and the magnitude of sex ratios in infant mortality rates was also examined. Notably, the magnitude of sex ratios in infant mortality rates declined significantly as sample sizes increased. These results suggest that previously reported marked sex ratios in infant mortality could be the product of stochastic variation in small samples.
ABSTRACT Studies of body weight variation in non-human primates have demonstrated not only season... more ABSTRACT Studies of body weight variation in non-human primates have demonstrated not only seasonal changes [1, 2], but that weights may fluctuate greatly during the course of a single day [1]. No reports, however, have demonstrated in detail how these changes occur over the course of a day. This study presents data on hourly changes in body weight in adult females and yearlings of provisioned free-ranging troops of Japanese macaques (Macaca fuscata). It is recommended that hourly changes be taken into consideration when collecting body weight data.
The quantification of nutritional status (e.g., total body fat) of animals is difficult, because ... more The quantification of nutritional status (e.g., total body fat) of animals is difficult, because the linear dimension (body length) required for the calculation of proxy parameters, such as the physique or body mass indices, cannot be measured without capture. One solution is photogrammetry of body length, provided the following two criteria are met: (1) the camera axes and subject are oriented vertically, and (2) anatomical landmarks are easily identified with low measurement error. By modifying Mori's (Primates 20:371-397, 1979) approach, we devised an accurate photogrammetric method that uses a horizontal bar with an attached ruler for the monkey to traverse, and the anatomical landmarks of the eye and upper border of the ischial callosity to measure body length. We tested the applicability of this method on 11 adult female, habituated, free-ranging Japanese macaques (Macaca fuscata). Somatometric body length (crown-rump length and anterior trunk length) was statistically compared with the body length obtained using photogrammetry. The significant correlation of the photogrammetric body length with each somatometric measurement verified that the former could be employed to calculate various indices that are used to characterize fat mass (nutritional status) in Japanese macaques. The advantages and disadvantages of photogrammetry are also discussed.
ABSTRACT We investigated the bodily mass of infants and postpartum adult females longitudinally i... more ABSTRACT We investigated the bodily mass of infants and postpartum adult females longitudinally in provisioned free-ranging Japanese macaque (Macaca fuscata) troops of the Takasakiyama Natural Zoo, Oita, Japan. We investigated whether the rate of mass change in postpartum adult females and infants is more strongly associated with season (or calendar date) as opposed to the length of time since delivery/birth. Focal adult females' postpartum mass ranged between 7 and 10 kg for a year after delivery. For postpartum adult females, calender date (season) influenced the rate of mass change more than the length of time since delivery did. Rate of mass change in postpartum adult females was high in October (autumn) and April and May (spring) and low between December and February (winter). This may reflect seasonality in energy and protein intake from natural foods. Infant mass increased steadily from birth. Mass of infants varied between individuals, some infants reached 2 kg by about 240 days of age, and others by about 400 days of age. It was unclear, however, whether the rate of mass change in infants was influenced more by age or calendar date (season). Differences in trends between adult females and infants may reflect, to some degree, differences in sources of energy intake, i.e. solid foods for adult females and suckling and solid foods for infants.
In a wild-living, artificially provisioned population of Japanese macaques at Takasakiyama in sou... more In a wild-living, artificially provisioned population of Japanese macaques at Takasakiyama in southern Japan, nine sets of twins were recorded from 12,392 known deliveries over a 56-year study period. Recorded twinning frequency was 0.073%. During the first 28-year period, artificial food was given until macaques were satiated and population size increased rapidly. In the second 28-year period, provisioned food was restricted to about half of the former period's calorific content. Seven sets of twins were born in the first period and two sets in the second. Twining frequency in the two periods was 0.137 and 0.027%, respectively. In comparing studies of other Catarrhine primate samples, we hypothesize that twinning frequency is influenced by living conditions, and we suggest that living conditions should be carefully evaluated in studies of twinning frequency.
From the late 1960s to the early 1970s, many congenitally malformed infants were born into provis... more From the late 1960s to the early 1970s, many congenitally malformed infants were born into provisioned Japanese macaque troops. Although the exact cause of this problem was not determined, the occurrence of malformations decreased thereafter. We examined possible factors such as total population size, number of adult females, birth rate, and volume of provisioned food. Agrichemicals attached to provisioned food are suspected as the main cause, as other factors were found to have no influence. Many more malformations were seen in males compared with females, in feet compared with hands, and in the fourth compared with other digits. We confirmed that the frequency of congenital malformation was high during the 1960s through to the mid-1970s when increased levels of provisioned food were given and that the incidence of congenital malformations was also elevated among wild macaques during this time.
Sex differences in infant mortality in provisioned Japanese macaque populations were examined usi... more Sex differences in infant mortality in provisioned Japanese macaque populations were examined using 10 data sets from five populations. The results indicate that there was no available data set in which a sex difference in infant mortality was statistically significant. To examine whether the observed sex ratios in infant mortality rates could be the product of stochastic variation in small samples, a correlation between sample size and the magnitude of sex ratios in infant mortality rates was also examined. Notably, the magnitude of sex ratios in infant mortality rates declined significantly as sample sizes increased. These results suggest that previously reported marked sex ratios in infant mortality could be the product of stochastic variation in small samples.
ABSTRACT Studies of body weight variation in non-human primates have demonstrated not only season... more ABSTRACT Studies of body weight variation in non-human primates have demonstrated not only seasonal changes [1, 2], but that weights may fluctuate greatly during the course of a single day [1]. No reports, however, have demonstrated in detail how these changes occur over the course of a day. This study presents data on hourly changes in body weight in adult females and yearlings of provisioned free-ranging troops of Japanese macaques (Macaca fuscata). It is recommended that hourly changes be taken into consideration when collecting body weight data.
The quantification of nutritional status (e.g., total body fat) of animals is difficult, because ... more The quantification of nutritional status (e.g., total body fat) of animals is difficult, because the linear dimension (body length) required for the calculation of proxy parameters, such as the physique or body mass indices, cannot be measured without capture. One solution is photogrammetry of body length, provided the following two criteria are met: (1) the camera axes and subject are oriented vertically, and (2) anatomical landmarks are easily identified with low measurement error. By modifying Mori's (Primates 20:371-397, 1979) approach, we devised an accurate photogrammetric method that uses a horizontal bar with an attached ruler for the monkey to traverse, and the anatomical landmarks of the eye and upper border of the ischial callosity to measure body length. We tested the applicability of this method on 11 adult female, habituated, free-ranging Japanese macaques (Macaca fuscata). Somatometric body length (crown-rump length and anterior trunk length) was statistically compared with the body length obtained using photogrammetry. The significant correlation of the photogrammetric body length with each somatometric measurement verified that the former could be employed to calculate various indices that are used to characterize fat mass (nutritional status) in Japanese macaques. The advantages and disadvantages of photogrammetry are also discussed.
Uploads
Papers by Hiroyuki Kurita