Welfare assessment of slow loris (Nycticebus spp.) at an Indonesian primate rehabilitation center: Development and validation of body condition score.

Body condition scoring (BCS) assessment can reflect animal welfare status and help the veterinarian to make a quick health management decision, including for confiscated slow loris (Nycticebus spp.). The confiscated slow loris should be rehabilitated in a rehabilitation center before being released. It is essential to monitor the welfare of slow loris to ensure that candidates are released. Assessment of animal welfare status requires representative measurable criteria and indicators. However, there is no standardized BCS for slow loris yet. This study focuses on developing and validating BCS based on body weight and circumference. In this study, 180 individuals were evaluated and scored. We measured body weight and circumferences to validate the assessment of BCS. There are no significant differences in body weight and circumferences within species and sexes. Muscle mass and fat deposits were palpated, visually viewed, and grouped in five BCS. There was a significant difference in body weight and circumference between BCS levels. According to this study, the development of BCS is valid and can be used to slow loris in prevailing circumstances and any ex-situ facilities.

Handedness heritability in industrialized and nonindustrialized societies.

In modern societies, there is a decreased usage of traditional weapons to settle interpersonal or inter-group disputes compared to usage in traditional societies, possibly affecting the frequency-dependent selection on the handedness polymorphism. Another societal difference is the extensive automation of hard manual labour (including agriculture) in industrialized societies, relaxing the selection for hand specialization. Thus, selection of handedness is likely to differ between traditional and modern societies. As heritability determines the relative speed of evolutionary dynamics, handedness heritability was compared between industrialized and non-industrialized societies. First, individuals were sampled from a non-industrialized area in Indonesia, where violent conflicts are relatively frequent and tribal wars have been prevalent recently. Handedness was recorded directly or indirectly for 11,490 individuals belonging to 650 independent pedigrees, and handedness heritability was estimated using a pedigree-based animal model. Second, estimates of handedness heritability derived from published sources were collected to compare heritability estimates, accounting for various confounding variables. Non-industrialized countries displayed a significantly higher heritability value (h2 = 0.56) than that of industrialized countries (h2 = 0.20). Heritability decreased with time along the twentieth century in industrialized countries, independently of the frequency of left-handedness, and independently of the method used to measure handedness. In conclusion, the data are consistent with a decrease in handedness heritability following the industrialization process and/or the associated decrease in violence using traditional weapons. The difference in heritability between industrialized and non-industrialized countries suggests that selection of handedness is thus likely to differ between traditional and modern societies.

Grouping behavior of Sumatran orangutans (Pongo abelii) and Tapanuli orangutans (Pongo tapanuliensis) living in forest with low fruit abundance.

In contrast to the African great apes, orangutans (Pongo spp.) are semisolitary: Individuals are often on their own, but form aggregations more often than expected by chance. These temporary aggregations provide social benefits such as mating opportunities. When fruit availability is high, costs of aggregating should be lower, because competition is less pronounced. Therefore, average party size is expected to be higher when fruit availability is high. This hypothesis would also explain why orangutans in highly fruit-productive habitats on Sumatra are more gregarious than in the usually less productive habitats of Borneo. Here, we describe the aggregation behavior of orangutans in less productive Sumatran habitats (Sikundur and Batang Toru), and compare results with those of previously surveyed field sites. Orangutans in Sikundur were more likely to form parties when fruit availability was higher, but the size of daily parties was not significantly affected by fruit availability. With regard to between-site comparisons, average party sizes of females and alone time of parous females in Sikundur and Batang Toru were substantially lower than those for two previously surveyed Sumatran sites, and both fall in the range of values for Bornean sites. Our results indicate that the assessment of orangutans on Sumatra as being more social than those on Borneo needs revision. Instead, between-site differences in sociality seem to reflect differences in average fruit availability.

Orangutan males make increased use of social learning opportunities, when resource availability is high.

Humans' colonization of diverse habitats relied on our ancestors' abilities to innovate and share innovations with others. While ecological impacts on innovations are well studied, their effect on social learning remains poorly understood. We examined how food availability affects social learning in migrant orangutan unflanged males, who may learn from local orangutans through peering (i.e., observational social learning). We analyzed 1,384 dyadic associations, including 360 peering events, among 46 wild Sumatran orangutan and 25 Bornean orangutan males, collected over 18 years. Migrants' peering rates significantly increased with higher food availability and time spent in proximity to others. Furthermore, migrants in the more sociable Sumatran population exhibited significantly higher peering rates compared to the Borneans, suggesting intrinsic and/or developmental effects of food availability on social learning. These findings emphasize the importance of investigating ecological effects on social learning on the immediate, developmental, and intrinsic levels for our understanding of cultural evolution.

Feeding ecology of free-ranging long-tailed macaques in East Java, Indonesia: Relationship with human food availability.

Food availability is an important factor affecting the feeding strategies of animals. Primate species living in habitats with high human activity have the potential to employ unique strategies to utilize human food resources. This study describes the feeding ecology of provisioned free-ranging long-tailed macaques (Macaca fascicularis) inhabiting Alas Purwo National Park, East Java, Indonesia. The activity budgets, dietary compositions, vertical usage, and ranging patterns of macaques were recorded between October 2021 and March 2022, and their relationships with the number of visitors (a proxy of human food availability) were examined. The macaques consumed more human food (mean ± SD: 53.9 ± 25.6%) than natural food (43.8 ± 25.5%), followed by unidentified food (2.3 ± 6.3%). Human food has several effects on the behavioral ecology of macaques, including reduced movement and increased social activity in response to the number of visitors, decreased consumption of natural food, frequent use of the ground and subcanopy strata, and decreased home range when the number of visitors increases. Thus, the relative importance of human food has substantially changed the essential behavioral ecology of provisioned macaque troops. Understanding the behavioral plasticity of macaques, particularly their responses to anthropogenic effects, could guide and contribute to the formulation of conservation policies and management plans.

Reproductive success of Bornean orangutan males: scattered in time but clustered in space.

Abstract: The social and mating systems of orangutans, one of our closest relatives, remain poorly understood. Orangutans (Pongo spp.) are highly sexually dimorphic and females are philopatric and maintain individual, but overlapping home ranges, whereas males disperse, are non-territorial and wide-ranging, and show bimaturism, with many years between reaching sexual maturity and attaining full secondary sexual characteristics (including cheek pads (flanges) and emitting long calls). We report on 21 assigned paternities, among 35 flanged and 15 unflanged, genotyped male Bornean orangutans (Pongo pygmaeus wurmbii), studied from 2003 to 2018 in Tuanan (Central Kalimantan, Indonesia). All 10 infants born since mid-2003 with an already identified sire were sired by flanged males. All adult males ranged well beyond the study area (c. 1000 ha), and their dominance relations fluctuated even within short periods. However, 5 of the 10 identified sires had multiple offspring within the monitored area. Several sired over a period of c. 10 years, which overlapped with siring periods of other males. The long-calling behavior of sires indicated they were not consistently dominant over other males in the area around the time of known conceptions. Instead, when they were seen in the area, the known sires spent most of their time within the home ranges of the females whose offspring they sired. Overall, successful sires were older and more often resident than others. Significance statement: It is difficult to assess reproductive success for individuals of long-lived species, especially for dispersing males, who cannot be monitored throughout their lives. Due to extremely long interbirth intervals, orangutans have highly male-skewed operational sex ratios and thus intensive male-male competition for every conception. Paternity analyses matched 21 immature Bornean orangutans with their most likely sire (only 10 of 50 genotyped males) in a natural population. Half of these identified sires had multiple offspring in the study area spread over periods of at least 10 years, despite frequently ranging outside this area. Dominance was a poor predictor of success, but, consistent with female mating tactics to reduce the risk of infanticide, known "sires" tended to have relatively high local presence, which seems to contribute to the males' siring success. The results highlight the importance of large protected areas to enable a natural pattern of dispersal and ranging. Supplementary Information: The online version contains supplementary material available at 10.1007/s00265-023-03407-6.

Stingless Bees Pollination Increases Fruit Formation of Strawberry (Fragaria x annanassa Duch) and Melon (Cucumis melo L.).

Stingless bees (Apidae: Meliponini) are distributed in tropical and subtropical areas in the world. Stingless bees are potential pollinator to increase yield of various crops species. We measured the pollination effectiveness of stingless bees, i.e., Tetragonula laeviceps in strawberry (Fragaria x annanassa) and Heterotrigona itama in melon (Cucumis melo) in the greenhouse. Pollination effectiveness of stingless bees were measured based on their visiting activities, i.e., foraging rate and flower handling time using focal sampling method. Measurements of fruit set consist of the number of fruits per plant, the number of normal and abnormal fruits, and the size and weight of fruits. Results showed that visiting activity of T. laeviceps in strawberry flowers ranged 2.33-2.73 flowers/3 min, while H. itama in melon flowers ranged 1.77-7.12 flower/3 min. Peak activities of H. itama in melon (7.12 flowers/3 min) occurred at 9.00 a.m. to 10.00 a.m., while T. laeviceps in strawberry (2.73 flowers/3 min) occurred at 11.00 a.m. to 12.00 p.m. Pollination by T. laeviceps increased 78.9% of fruit formation and reduced 16.7% of abnormal fruits of strawberry. In melon, ratio between female and male flowers was 0.03. The number of fruits produced in melon with T. itama (6.1 fruits/plant) was higher than in open field (2.6 fruits/plant) and control plants (no pollination) (0.2 fruits/plant). Pollination by H. itama increased fruit formation of melon.

Molecular diagnosis with the corresponding clinical symptoms of canine distemper virus infection in javan leopard (Panthera pardus ssp. melas).

Diseases are one of the possible threats to the conservation of wild cat populations. One disease that has been reported to infect and cause death, including in various wildlife, is the canine distemper virus (CDV). Here, we report the first case of CDV in an adolescent melanistic Javan female leopard in Indonesia. We combined the clinical report with the Reverse Transcription PCR (RT-PCR) analyses on the faecal and brain samples of partial nucleoprotein (CDV-N) and hemagglutinin (CDV-H) genes. We also performed analyses of urine, haematology, and blood chemistry. The CDV-H nucleotide sequence confirmed the CDV infection in the female leopard and was clustered to the CDV's Asia 1 genotype. This finding opens an investigating window to analyse the pathogen transmission between animals in wildlife, particularly to support the management of conservation in natural habitats in Indonesia.

Male Homosexual Preference: Femininity and the Older Brother Effect in Indonesia.

Male homosexual preference (MHP) is an evolutionary enigma because it is partially heritable and imposes a fertility cost. In occidental societies, homosexual men are feminized at various levels and they have more older brothers than heterosexual men. To evaluate whether femininity and the fraternal birth order (FBO) effect are universal features of MHP or not, we collected original data from homosexual men, heterosexual men, and heterosexual women from Java (Indonesia). Facial photographs were used to test whether homosexual faces are feminized when compared with heterosexual ones. We found that faces manipulated to resemble the average face of homosexual men are perceived as facially feminized, suggesting that homosexual men are facially feminized compared to heterosexual men, although a higher facial femininity was not captured by morphological analyses. Then, family data were used to detect differences in siblings' composition between homosexuals and heterosexuals. Homosexual men displayed a higher number of older brothers than heterosexual men, even when sibship size was controlled for, suggesting that the FBO effect exists in Indonesian populations. Independent of sexual orientation, men with older brothers seem more feminized than those without older brothers, consistent with the immune origin of the FBO effect. In conclusion, MHP in Indonesia is partially feminized and they have more older brothers. Such features are also associated with MHP in other cultural contexts, suggesting a cross-cultural effect of men homosexual preference. An evolutionary explanation is available for the feminizing effect, although the FBO effect remains unexplained even if proximal mechanisms start to be identified.

Morphometric, Behavioral, and Genomic Evidence for a New Orangutan Species.

Six extant species of non-human great apes are currently recognized: Sumatran and Bornean orangutans, eastern and western gorillas, and chimpanzees and bonobos [1]. However, large gaps remain in our knowledge of fine-scale variation in hominoid morphology, behavior, and genetics, and aspects of great ape taxonomy remain in flux. This is particularly true for orangutans (genus: Pongo), the only Asian great apes and phylogenetically our most distant relatives among extant hominids [1]. Designation of Bornean and Sumatran orangutans, P. pygmaeus (Linnaeus 1760) and P. abelii (Lesson 1827), as distinct species occurred in 2001 [1, 2]. Here, we show that an isolated population from Batang Toru, at the southernmost range limit of extant Sumatran orangutans south of Lake Toba, is distinct from other northern Sumatran and Bornean populations. By comparing cranio-mandibular and dental characters of an orangutan killed in a human-animal conflict to those of 33 adult male orangutans of a similar developmental stage, we found consistent differences between the Batang Toru individual and other extant Ponginae. Our analyses of 37 orangutan genomes provided a second line of evidence. Model-based approaches revealed that the deepest split in the evolutionary history of extant orangutans occurred ∼3.38 mya between the Batang Toru population and those to the north of Lake Toba, whereas both currently recognized species separated much later, about 674 kya. Our combined analyses support a new classification of orangutans into three extant species. The new species, Pongo tapanuliensis, encompasses the Batang Toru population, of which fewer than 800 individuals survive. VIDEO ABSTRACT.