Predicting Rice Lodging Risk from the Distribution of Available Nitrogen in Soil Using UAS Images in a Paddy Field.

Rice lodging causes a loss of yield and leads to lower-quality rice. In Japan, Koshihikari is the most popular rice variety, and it has been widely cultivated for many years despite its susceptibility to lodging. Reducing basal fertilizer is recommended when the available nitrogen in soil (SAN) exceeds the optimum level (80-200 mg N kg-1). However, many commercial farmers prefer to simultaneously apply one-shot basal fertilizer at transplant time. This study investigated the relationship between the rice lodging and SAN content by assessing their spatial distributions from unmanned aircraft system (UAS) images in a Koshihikari paddy field where one-shot basal fertilizer was applied. We analyzed the severity of lodging using the canopy height model and spatially clarified a heavily lodged area and a non-lodged area. For the SAN assessment, we selected green and red band pixel digital numbers from multispectral images and developed a SAN estimating equation by regression analysis. The estimated SAN values were rasterized and compiled into a 1 m mesh to create a soil fertility map. The heavily lodged area roughly coincided with the higher SAN area. A negative correlation was observed between the rice inclination angle and the estimated SAN, and rice lodging occurred even within the optimum SAN level. These results show that the amount of one-shot basal fertilizer applied to Koshihikari should be reduced when absorbable nitrogen (SAN + fertilizer nitrogen) exceeds 200 mg N kg-1.

A multidisciplinary view on cultural primatology: behavioral innovations and traditions in Japanese macaques.

Cultural primatology (i.e., the study of behavioral traditions in nonhuman primates as a window into the evolution of human cultural capacities) was founded in Japan by Kinji Imanishi in the early 1950s. This relatively new research area straddles different disciplines and now benefits from collaborations between Japanese and Western primatologists. In this paper, we return to the cradle of cultural primatology by revisiting our original articles on behavioral innovations and traditions in Japanese macaques. For the past 35 years, our international team of biologists, psychologists and anthropologists from Japan, France, Sri Lanka, the USA and Canada, has been taking an integrative approach to addressing the influence of environmental, sociodemographic, developmental, cognitive and behavioral constraints on the appearance, diffusion, and maintenance of behavioral traditions in Macaca fuscata across various domains; namely, feeding innovation, tool use, object play, and non-conceptive sex.

Affiliative interactions between one-male units in a band of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) living in the Qinling Mountains, China.

We studied affiliative behaviors that occurred within and between one-male units (OMUs) in a band of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) living in the Qinling Mountains, China for 3 years from 2002 to 2004. During the birth season, females handling infants of other females affiliatively interacted with females in neighboring OMUs as well as with females in their own OMU. After these interactions, affiliative encounters occurred without conflict between the OMUs. In the mating season, females sometimes presented their genitals to males of other OMUs. These interactions may facilitate the maintenance of a higher level social organization, a band. Therefore, the band composed of OMUs and all male group(s) is the basic unit of social structure of this species. Almost all other Asian colobines have OMUs that either maintain distance from each other or engage in territorial defense, so these OMUs would not be expected to form a band. Contrary to these species, the 3 species of Rhinopithecus spp. inhabiting China form a band composed of OMUs, because infants and females may function as a bridge connecting OMUs.

Modified Grey Model and its application to groundwater flow analysis with limited hydrogeological data: a case study of the Nubian Sandstone, Kharga Oasis, Egypt.

Groundwater flow at Kharga Oasis, located in the western desert of Egypt, was previously analyzed using numerical models; however, the lack of basic data often limits the implementation of these models, as well as introducing a problem for model calibration and validation. The Grey Model (GM) was used to overcome these difficulties of data limitation and uncertainty of hydrogeological conditions. However, no clear theories exist for selecting the number of input model trends and the most suitable values of input parameters. Therefore, in the current study, a modification of the GM is newly proposed and called the Modified Grey Model (MGM) in an attempt to determine a process for selecting the best input models' trends with the appropriate values of input parameters to achieve acceptable fitting to observations. The sensitivity analysis results showed that the MGM produced more stable results than the GM using a wide range of values for input parameters. Moreover, the MGM reduced the calculation time required for fitting the measured piezometric level trends by 99.8%. Three development scenarios of groundwater withdrawal were proposed that involved either expanding the present extraction rate or redistributing the groundwater withdrawal over the recent working production wells (RWPWs). The results concluded that the groundwater table in the northern part of the oasis could be temporally recovered to an economical piezometric level; however, the table in the southern part is severely decreased. Therefore, new production wells are recommended to be constructed in the southern part far enough from the RWPWs.

Intraspecies variation in dominance style of Macaca fuscata.

Knowledge of intraspecific variation is important to test the evolutionary basis of covariation in primate social systems, yet few reports have focused on it, even in the best-studied species of the Macaca genus. We conducted a comparative study of the dominance styles among three provisioned, free-ranging groups of Japanese macaques at Shodoshima Island, Takasakiyama Mountain and Shiga Heights, and collected standard data on aggressive and affiliative behavior during a period of 5 years. Our data in the Takasakiyama and Shiga groups support previous studies showing that Japanese macaques typically have despotic social relations; nevertheless, our data in the Shodoshima group are inconsistent with the norm. The social traits of Shodoshima monkeys suggested that: (1) their dominance style is neither despotic nor tolerant but is intermediate between the two traits; (2) some measures of dominance style, e.g., frequency and duration of social interactions, covary as a set of tolerant traits in Shodoshima monkeys. This study suggests broad intraspecific variation of dominance style in Japanese macaques as can be seen in some other primate species.

Male attacks on infants and infant death during male takeovers in wild white-headed langurs (Trachypithecus leucocephalus).

Infanticide was first observed in langurs nearly 50 years ago, and this rare phenomenon has been inferred to have either an evolutionarily adaptive function or to be a pathological and non-functional behavior. In this study, we report 5 male takeover events in one-male groups of white-headed langurs in the Nongguan Karst Hills, Guangxi, China from 1998 to 2006. We recorded 13 attacks on 9 infants by extra-group males or new resident males. During the male takeovers, all of the infants younger than 6 months (with an average age of 3.6 months [N = 11]) in the groups disappeared. The infant death rate during the 4.2 months after takeover by a new male was significantly higher than the infant death rate calculated for most of the year. Older infants that were still nursing (with an average age of 14.1 months [N = 7]) were often attacked and seriously wounded by the extra-group males or new resident males, but all of them survived. The interbirth intervals of females whose infants were assumed to be killed by males were significantly reduced relative to those of females in groups with stable male tenure (mean = 10 months vs 25 months). Our data suggest that males kill unrelated and unweaned infants during the takeover period to decrease the time until the infants' mothers resume fertility. Thus, infanticide would support sexual selection theory in white-headed langurs. The data also show that infanticidal behavior was directed toward the infants, especially those who were still nursing. Female dispersal may function as a counter-strategy to avoid infanticide.

Identification of individual adult female Javan lutungs (Trachypithecus auratus sondaicus) by using patterns of dark pigmentation in the pubic area.

In a series of field surveys of wild Javan lutungs (Trachypithecus auratus sondaicus) conducted at Pangandaran Nature Reserve in West Java, Indonesia, from 2011 to 2012, we tried to use a method of individual identification by using individual-specific patterns of dark pigmentation in the pubic area. During the 2011 dry season, we used a digital SLR camera with a 400-mm telephoto lens to photograph the pubic area of each individual of a habituated group. These photographs were the basis for identifying 14 different adult females. During the rainy season of 2011 and the dry season of 2012, we checked the presence/absence of each of the identified individuals and found that these patterns were stable, at least during our study period. We found that two adult females and one adult female disappeared from the subject group between the first and second and between the second and third surveys, respectively, and that one adult female gave birth between the first and second surveys, but the infant had disappeared from the group between the second and third surveys. We could not confirm the validity of the method for juvenile females because of the dense white hair in their pubic areas and the fact that few individuals had clear patterns. Furthermore, we could not use this method for males because of the lack of pigmentation in the pubic area. As patterns of pigmentation in the pubic area are known to be present in other Trachypithecus species, our method can be useful for identification of individual adult females of these species, on which few individual-based behavioral studies have been conducted. Collecting individual-based behavioral data would enable us to track the presence of individuals in groups or movements between groups; determine the effects of social rank and age on within-group competition and copulation; and examine population data.

Food-snatching behavior of free-ranging Japanese macaques observed on Shodoshima Island: a preliminary report.

We investigated the characteristics of a particular food-snatching behavior in which one individual forced another's mouth open and grabbed the food, as performed by free-ranging Japanese macaques (Macaca fuscata) in Choshikei Monkey Park on Shodoshima Island, western Japan. We conducted a survey in late June 2012 and observed one of two monkey troops, comprising 214 monkeys. We recorded the age classes and sexes of the individuals who performed the snatching behavior and were snatched from, and examined the effects of provisioned food distribution and quantity on the frequency of snatching trials and success. During the survey, we recorded 747 snatching trials, of which 609 were successful, all of which were performed by seven individuals: one adult male and six adult females. The snatching behavior occurred only during provisioning. The target animals were primarily juveniles (650 trials, 578 successful), while cases in which food was snatched from adult females (93 trials, 30 successful) and subadult females (4 trials, 1 success) were less frequent. Among the juveniles, small juveniles had food snatched more frequently than large juveniles. The higher frequency of snatching trials against juveniles was likely due to their subordinate nature. Neither the distribution nor quantity of the provisioned foods had significant effects on the number of snatching trials and successes, while the time elapsed after provisioning had significant negative effects, attributed to a decrease in the number of wheat grains left within the mouth pouch of the potential target animals.

Impact of group size on female reproductive success of free-ranging Rhinopithecus roxellana in the Qinling Mountains, China.

Group size influences female reproductive success through scramble/contest feeding competition, predation pressures and infanticide risks in primates. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is an endangered folivorous colobine species living in a multilevel society. From 2002 to 2008, we studied a free-ranging band of R. roxellana in the Qinling Mountains of China to examine the effect of group size on female reproductive success. During our observation period, the number of monkeys in the study band fluctuated from 61 to 108, and the number of one-male/multi-female groups within it varied from 7 to 10. A significant negative linear relationship was found between group size and birth rate, but group size was not significantly correlated with infant survival rate or interbirth interval. These results suggest that group size influences female reproductive success via within-group scramble competition in this folivorous species.

Sleeping cluster patterns and retiring behaviors during winter in a free-ranging band of the Sichuan snub-nosed monkey.

Little information is available on the sleeping cluster pattern and retiring behavior of Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Here, we provide observational data on a provisioned free-ranging band in the Qinling Mountains, central China. The results suggest that winter night activity of R. roxellana is a compromise between antipredator and thermoregulatory strategies and an adaptation to ecological conditions of their temperate habitat. Monkeys retired between 1804 and 1858 h in winter. In support of the antipredation hypothesis, all monkeys slept in trees at night, whereas 18.8% of individuals slept on the ground during the day. Also, the study band was more spatially cohesive at night than in daytime, with shorter distances between one-male units. Keeping warm is critical for survival in freezing temperatures. Monkeys often slept in the lower stratum of the tree canopy, avoiding the upper canopy where it is cold and windy. They formed larger sleeping clusters at night than in daytime. The most common types of night-sleeping clusters were adult females and juveniles, followed by adult females with other adult females. These accounted for 60.2% of the total records. The frequency of female-male clusters is two times greater, and that of adult male-juvenile clusters was four times less at night than during the day. The variations in composition of sleeping clusters suggest affiliative patterns at night-sleeping sites differ from those during the day.

Sexual interference in the Golden snub-nosed monkey (Rhinopithecus roxellana): a test of the sexual competition hypothesis in a polygynous species.

Sexual interference (SI), which is defined as any disturbance directed to a mating pair by other individuals, has been reported in several primate species. It is widely suggested that successful harassers experience improved mating success by increasing their access to reproductive partners as well as by reducing the mating success of rivals. Although theories of primate sexual conflict highlight male intra-sexual mating competition, females also are reported to actively disrupt copulations between mating partners. In this study, we investigated SI in a multilevel troop of Golden snub-nosed monkeys (Rhinopithecus roxellana) inhabiting the Qinling Mountains, China. Behavioral observations of 11 one-male units (OMU) that comprised the multilevel troop were conducted from September 2007 to May 2008. During this period 17.1% of 652 documented intra-OMU sexual encounters were characterized either by mild or aggressive forms of harassment. Sexual harassment was typically performed by a single individual (91.9%), and in 75.7% of cases the harasser was an adult or sub-adult female. The frequency of female harassment was positively correlated with the number of adult and sub-adult females residing in an OMU, and resulted in a significant decrease in matings ending in ejaculation. We found that the amount of SI a female received was not a significant predictor of her reproductive success. However, females who conceived during the mating season directed higher levels of harassment at other females than females who did not conceive. We evaluate the strength of the sexual competition hypothesis and the hormonally modulated aggression hypothesis in explaining patterns of SI in female Golden snub-nosed monkeys.

Social dynamics of the golden snub-nosed monkey (Rhinopithecus roxellana): female transfer and one-male unit succession.

Among primates that form multilevel societies, understanding factors and mechanisms associated with the movement of individuals between groups, clans, and one-male social units offers important insight into primate reproductive and social strategies. In this research we present data based on an 8-year field study of a multilevel troop of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains of China. Our study troop contained 78-126 individuals, and was usually organized into 6-8 one-male units (OMU). The majority of OMUs were composed of networks of unrelated females and their offspring. We found that 59.7% (43/72) of subadult and adult females in our study troop transferred between OMUs (n=66) or disappeared (n=7) from the troop. In the majority of cases, two or more females transferred together into new OMUs or troops. In R. roxellana, new OMUs formed in several ways. During 2001-2008, 16 adult males appeared in the study troop. Over this period, we observed 13 different males who became harem leaders either by taking over an existing harem or by attracting females from other OMUs into their harem. We also observed four OMUs from a neighboring troop to successfully immigrate into the study troop. The number of individuals in these newly immigrated OMUs was significantly smaller than that number of individuals in resident OMUs. During harem formation, fighting between adult males was rarely observed, and female mate choice appeared to play a crucial role in harem male recruitment and replacement. These results suggest that golden snub-nosed monkeys are organized in a nonmatrilineal social system. Female mate choice and possibly incest avoidance appear to play important roles in female transfer, male tenure, and OMU stability.

Free-ranging macaque mothers exaggerate tool-using behavior when observed by offspring.

The population-level use of tools has been reported in various animals. Nonetheless, how tool use might spread throughout a population is still an open question. In order to answer that, we observed the behavior of inserting human hair or human-hair-like material between their teeth as if they were using dental floss in a group of long-tailed macaques (Macaca fascicularis) in Thailand. The observation was undertaken by video-recording the tool-use of 7 adult females who were rearing 1-year-old infants, using the focal-animal-sampling method. When the data recorded were analyzed separately according to the presence/absence of the infant of the target animal in the target animal's proximity, the pattern of the tool-using action of long-tailed adult female macaques under our observation changed in the presence of the infant as compared with that in the absence of the infant so that the stream of tool-using action was punctuated by more pauses, repeated more often, and performed for a longer period during each bout in the presence of the infant. We interpret this as evidence for the possibility that they exaggerate their action in tool-using so as to facilitate the learning of the action by their own infants.

Evaluation of uncertainties originating from the different modeling approaches applied to analyze regional groundwater flow in the Tono area of Japan.

Qualitative evaluation of the effects of uncertainties originating from scenario development, modeling approaches, and parameter values is an important subject in the area of safety assessment for high-level nuclear waste disposal sites. In this study, regional-scale groundwater flow analyses for the Tono area, Japan were conducted using three continuous models designed to handle heterogeneous porous media. We evaluated the simulation results to quantitatively analyze uncertainties originating from modeling approaches. We found that porous media heterogeneity is the main factor which causes uncertainties. We also found that uncertainties originating from modeling approaches greatly depend on the types of hydrological structures and heterogeneity of hydraulic conductivity values in the domain assigned by modelers. Uncertainties originating from modeling approaches decrease as the amount of labor and time spent increase, and iterations between investigation and analyses increases.

Mate competition and reproductive correlates of female dispersal in a polygynous primate species (Rhinopithecus roxellana).

Different mating systems in group-living animals have characteristic behavioral correlates that are primarily related to mate competition. Mate competition may push individuals to selectively make dispersal decisions for the purpose of maximizing of opportunities for reproduction. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is a polygynous primate species endemic to China. We provide the first data on female dispersal in a free-ranging group of R. roxellana in the Zhouzhi National Nature Reserve, Qinling Mountains, China. Both adult and subadult female dispersal occurred. Immigration/emigration rates of adult females are higher than those of subadult females. Mate competition is one apparent driving force behind adult female dispersal, and inbreeding avoidance is the possible proximate factor influencing subadult female dispersal. Adult female R. roxellana employ various reproductive strategies related to dispersal, which may increase their reproductive success.

First evidence on foot preference during locomotion in Old World monkeys: a study of quadrupedal and bipedal actions in Sichuan snub-nosed monkeys (Rhinopithecus roxellana).

This is the first report of foot preference during locomotion in Old World monkeys. Foot preferences during the quadrupedal walking action and the bipedal shifting action of a naturalistic group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in Zhouzhi National Nature Reserve in the Qinling Mountains of China were investigated. Twelve of 21 individuals tested on quadrupedal action and all 21 individuals tested on bipedal action exhibited a significant foot preference. Both significant right- and left-footed preferences were observed; sex affected neither direction nor strength of foot preference in both actions. The finding that 61.90% of focal R. roxellana showed a right-foot preference, both in quadrupedal action based on the footed index and in bipedal action based on the z-score, is in partial agreement with the postural origin hypothesis on footedness. Foot preference was significantly stronger in bipedal action than in quadrupedal action, supporting the view that posture could be a crucial factor influencing foot preference as well as hand preference in this species.

Female social dynamics in a provisioned free-ranging band of the Sichuan snub-nosed monkey (Rhinopithecus roxellana) in the Qinling Mountains, China.

Little information is available on the social dynamics of the Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Here, we provide 5-year observational data on a provisioned free-ranging band in the Qinling Mountains, central China, from October 2001 to December 2005. The results of this study suggested that females place a high priority on maintaining long-term relationships with other female in their one-male units (OMUs). Females had more social interactions with unit members than with nonunit individuals. They showed relatively high rates of affiliation with their unit females, intermediate levels with the resident males, and low levels with individuals outside the unit. Females had few interactions with other resident males. Social interactions, especially affiliative interactions, were more symmetrical between focal females and their unit females than between focal females and the resident males. Thus female social interactions appeared to resemble those of other female-bonded primate societies. On the other hand, female transfers occurred sometimes. We recorded 11 cases of female immigration and 5 cases of female disappearance, 1 case of female intraband shift, and 2 cases of "merging of OMUs," which suggested that unit females might be loose-knit in this species. We discussed influencing factors on female Sichuan snub-nosed monkey social dynamics, by comparing them with those of Hamadryas and gelada baboons that also have multilevel societies.

Dominance relationships among one-male units in a provisioned free-ranging band of the Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains, China.

We studied the dominance relationships among one-male units (OMUs) in a provisioned free-ranging band of the Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains of central China from 2001 to 2005. The band was composed of 6-8 OMUs that stayed in the band for several years. Linear dominance orders could be detected using displacement interactions with directional asymmetry among OMUs in 82.3+/-5% of interactions, and ambiguous and reversed interactions in 17.7+/-5%. The dominance rank of OMUs was positively related with the duration of their stay in the band, and this may be attributed to the association of the resident male with adult females, rather than the fighting ability of resident males, as males do not fight seriously with each other. Subordinate units were observed to merge with dominant units resulting in an elevation of their rank order. The linear dominance relationship among OMUs in the Sichuan snub-nosed monkeys may have evolved as a result of competition for preferred food trees.

Hand preference during unimanual and bimanual reaching actions in Sichuan snub-nosed monkeys (Rhinopithecus roxellana).

Hand preferences were investigated during one unimanual action (food-reaching) and one bimanual action (mount-reaching) in a semi-free-ranging group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in Zhouzhi National Nature Reserve, Qinling Mountains of China. Nine of 14 individuals tested on the unimanual food-reaching action and all six individuals tested on the bimanual mount-reaching action exhibited a manual preference. Both significant right- and left-handed preferences were observed in the two actions. Sex did not affect either direction or strength of hand preference in the unimanual action. Hand preference for the bimanual action was stable over time, and the strength of hand preference was significantly stronger in the bimanual action than in the unimanual action.

First wild evidence of neonate nipple preference and maternal cradling laterality in Old World monkeys: a preliminary study from Rhinopithecus roxellana.

Although captive or free-ranging settings offer a more controlled environment for assessing non-human primate laterality, research on wild populations provides evidence of how laterality is affected by natural environmental conditions and, thus may yield potential insights into the evolution of laterality. This study of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) constitutes the first report on asymmetric patterns of early mother-infant interactions among Old World monkeys in the wild. It was found that neonate nipple preference and maternal cradling laterality are both evident on the individual level. Although there is no significant group-level preference direction, the group preference strength on both measures is evident. Moreover, neonate nipple preference is not significantly correlated with maternal cradling laterality on either LBI scores or the direction (LBI scores: r=0.174, p=0.632; direction: r=0.624, p=0.054). Taken together, it is possible to suggest that wild R. roxellana show independent orientation laterality from the first week of life.