Origin and evolution of the sulawesi macaques 1. Electrophoretic analysis of hemoglobins

The monkeys on the island of Sulawesi (Celebes), Indonesia, comprise seven species ofMacaca, that isM. maura, M. tonkeana, M. hecki, M. nigrescens, M. nigra, M. ochreata, andM. brunnescens. Hemoglobins from 248 individuals of these seven species were analyzed by isoelectric focusing electrophoresis (IEFE) and by starch gel electrophoresis in the presence of urea (USGE). Eighteen phenotypes consisting of eight molecular types were identified by IEFE analysis. The speciestonkeana inhabiting the central part of the island revealed 11 phenotypes, while peripheral species such asnigrescens andbrunnescens carried only 3 and 2 phenotypes, respectively. On USGE, three α chains and three β chains were identified and named α1, α2, and α6, and β1, β3, and β5, respectively. The α1 chain has the same mobility as the α chains of other macaques, while the α2 chain is less positively charged than α1, and α6 is the least positive among these α chains. The α2 chain is widely distributed in the Sulawesi macaques as the major component. Four species,ochreata, tonkeana, maura, andnigrescens, carried the α1 and α6 chains as minor components. The electrophoretic mobility of β1 was the same as that of other macaques, while β3 and β5 were more positively charged and less positively charged than β1, respectively. All of the Sulawesi species had β3 in high or low gene frequencies and inmaura, tonkeana, andbrunnescens, this type was most abundant. β5 chain existed in the species of the northern peninsula, as the major type. The subordinate type was β3 innigra andnigrescens and β1 inhecki. On the other hand, β1 was most frequently observed inochreata.     

Vocal communication in adult greater horseshoe bats, Rhinolophus ferrumequinum

Whereas echolocation in horseshoe bats is well studied, virtually nothing is known about characteristics and function of their communication calls. Therefore, the communication calls produced by a group of captive adult greater horseshoe bats were recorded during various social interactions in a free-flight facility. Analysis revealed that this species exhibited an amazingly rich repertoire of vocalizations varying in numerous spectro-temporal aspects. Calls were classified into 17 syllable types (ten simple syllables and seven composites). Syllables were combined into six types of simple phrases and four combination phrases. The majority of syllables had durations of more than 100 ms with multiple harmonics and fundamental frequencies usually above 20 kHz, although some of them were also audible to humans. Preliminary behavioral observations indicated that many calls were emitted during direct interaction with and in response to social calls from conspecifics without requiring physical contact. Some echolocation-like vocalizations also appeared to clearly serve a communication role. These results not only shed light upon a so far widely neglected aspect of horseshoe bat vocalizations, but also provide the basis for future studies on the neural control of the production of communicative vocalizations in contrast to the production of echolocation pulse sequences.     

Ranging patterns and habitat use of Sulawesi Tonkean macaques (Macaca tonkeana) in a human-modified habitat

The goal of this study was to investigate the ecological flexibility of Tonkean macaques (Macaca tonkeana) by examining how they respond to human-induced habitat alteration. To do so, I observed movement patterns, forest strata use, microhabitat use, and home range use in two groups that occupied habitats with different levels of human alteration and habitat quality in Lore Lindu National Park, Sulawesi, Indonesia. The group occupying the heavily altered habitat (Anca) spent a significantly greater proportion of time traveling on the ground than the group in minimally altered habitat (CH), and significantly more time than expected in microhabitats within their range that were characterized by greater alteration (e.g., agroforestry areas). There was no significant difference between the two groups in daily path length, despite differences in group size. The Anca group exhibited a greater home range area per individual than the CH group, and utilized a more limited area within their home range with greater intensity, relative to the CH group. Tonkean macaques therefore show considerable flexibility in response to anthropogenic disturbance by adjusting their use of forest strata to facilitate travel and increase foraging opportunities and by intensively using particular areas within their home range where known resources are present and predictably available.     

Long-term data on basic reproductive parameters and evaluation of endocrine,morphological, and behavioral measures for monitoring reproductive status in a group of semifree-ranging Tonkean macaques (Macaca tonkeana)

Cycle and gestation lengths, menstruation patterns, female genital swelling characteristics, and male-female consortship durations are reported in a semifree-ranging group of Tonkean macaques (Macaca tonkeana) studied over a 12 year period. In addition, profiles of urinary estrone conjugates (E1C) and immunoreactive pregnanediol glucuronide (PdG) throughout four complete menstrual cycles in two females and three full-term pregnancies are presented. Based on intermenstrual intervals, a mean cycle length of 37–41 days (n = 55 cycles in 10 females) was found. Gestation length averaged 173 days (n = 27 pregnancies in eight females). Measurement of PdG immunoreactivity in urine revealed a cyclic pattern with a 5–15-fold increase between follicular and luteal phase concentrations, suggesting that PdG is a reliable indicator of ovarian cyclicity and luteal function. In contrast to PdG, E1C excretion showed no clear pattern throughout the cycle; however, highest values of E1C were usually found shortly before the onset of the luteal phase PdG rise at the presumed time of ovulation. Levels of both hormones were elevated during the first half of gestation and showed a marked increase throughout the second half, with maximum E1C concentrations being up to 100-fold higher than nonpregnant levels. Consortships by the male and occurrence of female genital swelling were long lasting (on average 5–10 days and 13 days, respectively) and were restricted to the follicular phase of the cycle. The day of maximal swelling and day of detumescence as well as the end of male consortship were closely associated with the periovulatory period. Swellings and consortships were longer following lactational ammenorhea than for subsequent cycles. The evolutionary significance of the cyclical changes undergone by females upon their relations with males is discussed. © 1996 Wiley-Liss, Inc.     

Vocal communication in lion-tailed macaques (Macaca silenus)

Investigations of vocal communication in captive groups of lion-tailed macaques (Macaca silenus) revealed a repertoire of 17 basic patterns. Sixteen of them were recorded and their physical parameters analysed by sonagrams. During a field study these results were verified and complemented, and additional data on the vocal behaviour of this species were gathered. The vocal repertoire of lion-tailed macaques is characterized by discretely structured, mostly interaction- and situation-specific sound patterns. The fundamental characteristics of vocal communication seem to be adjusted to the acoustic conditions of the rain forest habitat as well as to the social organization in 1-male groups. In contrast to other species of the macaque genus, lion-tailed macaques are highly adapted to a strictly arboreal life in the rain forests of the Western Ghats (South India). Due to the dense vegetation in this habitat, propagation of visual signals is restricted to short distances. Vocal signals are therefore of great importance. The vocal repertoire of lion-tailed macaques differs from that of more terrestrial macaques insofar as the basic patterns show comparatively insignificant structural variations. Also, patterns were recorded which have not yet been found in any other member of the genus.     

Effects of six-day maternal separation on tonkean macaque infants

Maternal separation may induce a depressive state in infant macaques. However, this does not occur in all macaque species. From present hypotheses, it may be predicted that infants belonging to a species characterized by open and tolerant social relationships should not develop severe depressive symptoms. Tonkean macaques (Macaca tonkeana) stand as such a species. The goal of the study was to verify that the infant’s reaction to mother loss is related to the social environment. The mothers of eight 5- to 9-month-old infants were removed during 6-day experimental periods. Infants’ behavior was characterized by a mild initial protest stage, followed by a slight decrease in activity during later maternal separation, and quick recovery after the mother’s return. No despair stage occurred. During separation, group members compensated for mother’s absence by cradling the infants. That social networks determine the intensity of the infant’s response to separation has far-reaching implications with regard to the meaning of depression occurrence within social networks.     

Vocal communication of wild bonnet macaques (Macaca radiata)

Field observations and spectrographic analyses of sound recordings of South Indian bonnet macaques revealed a vocal repertoire of at least 25 basic patterns. The repertoire consists of well separated sound classes and acoustic categories connected by structural intergradation. Besides structural variations within and between different elements of the repertoire, the vocal system ofMacaca radiata is characterized by regular combinations of particular basic patterns. These combinations occurred not only between calls of similar structure and function but also between calls usually emitted in entirely different social contexts. According to the qualitative analysis, sex-specific asymmetries of the vocal behaviour were less pronounced than age-dependent characteristics. The comparison of clear call vocalizations ofMacaca radiata andM. fuscata revealed significant species-specific differences on the structural and the behavioural level. Evaluations of the structural features of alarm calls of various macaque species imply marked differences between members of thefascicularis group andsinica group on one hand and thesilenus group andarctoides group on the other.     

Vocal communication in captive golden monkeys (Rhinopithecus roxellanae)

The Sichuan golden snub-nosed monkey,Rhinopithecus roxellanae, is an endangered Colobine endemic to China. The behavior and biology of this species are little known, and it has rarely been kept in captivity outside China. Results from 42 hr of observations of a male-female golden monkey pair provide preliminary information on the vocal behavior of this species in captivity. Vocalizations by the animals often occurred within antiphonal sequences, which were primarily initiated by the female. Sequences were brief (2–3 calls), showed little or no temporal overlap, and were emitted primarily when the animals were distal from one another, suggesting that sequences may function as contact calls in nature. Some vocalizations appeared to be cryptic, i.e. unaccompanied by mouth or body movement, and these were observed more often than noncryptic calls in both animals. Vocal communication appears to be complex in this species, and remains poorly understood.     

Confirmation and location of the hybrid zone between wild populations of Macaca tonkeana and Macaca hecki in Central Sulawesi,Indonesia

Reports of hybridization between Macaca tonkeana and Macaca hecki were investigated in Central Sulawesi, Indonesia. We defined sets of morphological traits that were diagnostic for M. tonkeana and M. hecki and then located an areas where animals had intermediate or mosaic features. Hybridization as indicated by morphology was detected between M. tonkeana and M. hecki. The hybrid zone appeared to be strongly centered at the road that crosses the isthmus of Central Sulawesi from Tawaeli to Toboli. Macaques in this region were not morphologically uniform; animals from the western area of the Tawaeli–Toboli road resembled M. hecki, while animals from the eastern area resembled M. tonkeana. The hybrid zone was found to be smaller than previously thought, with maximum dimensions of approximately 15 and 7.5 km. Clines for diagnostic morphological features were broadly coincident, suggesting that the hybrid zone originated by secondary contact. Analysis of three museum specimens collected in 1916 provided evidence that the hybrid zone has been in existence since at least then. The narrow width of the hybrid zone, along with its age, suggested that some prezygotic or postzygotic barrier must exist to full introgression between M. tonkeana and M. hecki. Am. J. Primatol. 43:181–209, 1997. © 1997 Wiley-Liss, Inc.     

Discrimination of macaques by macaques: the case of Sulawesi species

A series of work by the first author have demonstrated that many macaque species show a visual preference for the pictures of their own species when the monkeys actively press a lever to see the pictures. We expanded this study to Sulawesi macaques kept as a pet by local people with slight modification. All seven species of Sulawesi macaques were passively exposed to a variety of colored slides of Sulawesi macaques. The experimenter recorded the duration of visual fixation onto the pictures. Male monkeys of all the seven species clearly watched the pictures of their own species for longer duration than those of the other species. Such visual preference suggested that the seven Sulawesi macaques discriminate each other species and, thus, they may not be integrated into fewer number of species. This visual preference may work to prevent overall intergradation of the Sulawesi macaques who sometimes have hybrid zones only in limited areas. This preference was in general weaker in female monkeys. In one species,Macaca ochreata, females actively avoided to see the pictures of conspecifics. These results may be related to how female monkeys interact with other individuals.     

The tiny difference between foraging and communication buzzes uttered by the Mexican free-tailed bat, <Emphasis Type="Italic">Tadarida brasiliensis</Emphasis>

Echolocating insectivorous bats consummate prey captures using a distinct vocal motor pattern commonly known as the terminal or feeding buzz, which is widely considered a fixed motor pattern executed independently of auditory feedback influences. The Mexican free-tailed bat, Tadarida brasiliensis, offers an opportunity to explore the role of sensory feedback in buzzing because they emit similar buzzes both in flight during foraging and while stationary as communication sounds. Here we compared the spectral and temporal patterns of foraging and communication buzzes to address whether or not auditory feedback may influence buzz patterns. We found that while foraging buzzes uttered in open space were composed of generic FM calls, communication buzzes were composed of an adapted CF–FM call similar to the call type used by T. brasiliensis when navigating in confined spaces. This provides the first evidence that some bats can make significant context-dependent changes in the spectral parameters of calls within their buzz. We also found that inter-pulse intervals, but not call durations, were different within the two buzz types. These observations indicate that though a common pattern generator hierarchically organizes all buzzes, T. brasiliensis retains a significant capacity to adapt the spectral and temporal patterns of elements within its buzzes.     

Thoracic radiography of pet macaques in Sulawesi, Indonesia

This report describes the results from a study of thoracic radiographs taken on a sample (n = 20) of pet macaque monkeys (Macaca) on the Indonesian island of Sulawesi. We present findings relating to general thoracic health, as well as describe our field methods and outline some of the challenges of conducting thoracic radiography in remote areas of the developing world. Examination of the radiographic images identified six possible cases of cardiac enlargement, and one case of minor lung consolidation possibly consistent with tuberculosis. The study did not identify major radiographic evidence of significant respiratory illness in the monkeys as might be expected based on the intense exposure to human respiratory diseases. These largely negative findings may be in part a consequence of image quality which seems to be influenced by power output and incomplete inspiration during film exposure.     

Handedness found in a wild group of moor monkeys Macaca maurus in the Karaenta Nature Reserve, South Sulawesi,Indonesia

Hand preference of wild moor monkeys Macaca maurus was investigated in food reaching situations at the Karaenta Nature Reserve, South Sulawesi, Indonesia. The frequency picking up sweet-corn grains to take into the mouth by either hand of monkeys was counted directly at the feeding ground where sweet-corn grains were scattered for monkeys. Among the 20 monkeys examined, 8 were fight-handed, 8 were left-handed, and 4 were ambilateral. The results indicated the prevailed hand preference on individual level but not either trends of left- or right-hand preference on population level. The trend toward a higher proportion of left-handed monkeys found in Japanese and rhesus monkeys was not found. Some other characteristics found in moor monkeys are discussed in comparison with those previous findings in Japanese and Tibetan macaques in order to evaluate variations within the genus Macaca.     

Social and vocal behavior in adult greater tube-nosed bats (Murina leucogaster)

Many studies have revealed the significant influence of the social nature and ecological niche of a species on the design and complexity of their communication sounds. The knowledge of communication sounds and particularly of the flexibility in their use among mammals, however, remains patchy. Being highly vocal and social, bats are well suited for investigating vocal plasticity as well as vocal diversity. Thus, the overall aim of this study was to test the presence of structural overlap between calls used in social communication and echolocation pulses emitted during foraging in greater tube-nosed bats (Murina leucogaster). Acoustic analysis and spectrotemporal decomposition of calls revealed a rich communication repertoire comprising 12 simple syllables and 5 composites with harmonics in the ultrasonic range. Simultaneous recording of vocal and social behavior in the same species yielded a strong correspondence between distinct behaviors and specific call types in support of Morton's motivation-structure hypothesis. Spectrographic analysis of call types also revealed the presence of modified components of echolocation pulses embedded within social calls. Altogether, the data suggest that bats can parse complex sounds into structurally simpler components that are recombined within behaviorally meaningful and multifunctional contexts.     

Vaccine protection against the SARS-CoV-2 Omicron variant in macaques

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Vocal communication in frogs

The robust nature of vocal communication in frogs has long attracted the attention of natural philosophers and their biologically inclined successors. Each frog species produces distinctive calls that facilitate pre-mating reproductive isolation and thus speciation. In many terrestrial species, a chorus of simultaneously calling males attracts females to breeding sites; reproductive females then choose and locate one male, using distinctive acoustic cues. Males compete with each other vocally and sometimes physically as well. Anuran acoustic signaling systems are thus subject to the strong pressures of sexual selection. We are beginning to understand the ways in which vocal signals are produced and decoded by the nervous system and the roles of neurally active hormones in both processes.     

Structure-guided foraging in long-tailed macaques

The aim of this study was to identify some of the cues that macaques follow when they search for new food sites. A social group of 37 long-tailed macaques was confined to a holding cage while an experimenter concealed food in an outdoor enclosure according to one of the following rules: (1) along the edge of a visible environmental border, (2) within structures of the same general type, or (3) along an ecologically irrelevant, invisible straight line. To provide the animals with a cue for detecting the rule, three piles of visible food were also presented according to the rule. Each of the 60 trials involved a different location in the 880 m² enclosure. The animals showed clear evidence of utilizing the first two rules from the outset of testing and the third rule about five trials. The animals found concealed food along environmental borders and within matching objects more quickly than along invisible lines. They also showed a rapid improvement in food finding on the invisible line. The results suggest that long-tailed macaques extend their search for food to a given class of environmental structure rather than exclusively by pure spatial gradients. © 1996 Wiley-Liss, Inc.