Comparative analyses of age- and sex-specific patterns of vocal behaviour in four species of Old World monkeys

Sound recordings and behavioural data were collected from four primate species of two genera (Macaca, Presbytis). Comparative analyses of structural and behavioural aspects of vocal communication revealed a high degree of intrageneric similarity but striking intergeneric differences. In the two macaque species (Macaca silenus, Macaca radiata), males and females shared the major part of the repertoire. In contrast, in the two langurs (Presbytis johnii, Presbytis entellus), many calls were exclusive to adult males. Striking differences between both species groups occurred with respect to age-specific patterns of vocal behaviour. The diversity of vocal behaviour was assessed from the number of different calls used and the proportion of each call in relation to total vocal output for a given age/sex class. In Macaca, diversity decreases with the age of the vocalizer, whereas in Presbytis the age of the vocalizer and the diversity of vocal behaviour are positively correlated. A comparison of the data of the two genera does not suggest any causal relationship between group composition (e.g. multi-male vs. one-male group) and communication system. Within each genus, interspecific differences in vocal behaviour can be explained by differences in social behaviour (e.g. group cohesion, intergroup relation, mating behaviour) and functional disparities. Possible factors responsible for the pronounced intergeneric differences in vocal behaviour between Macaca and Presbytis are discussed.     

Species differences of male loud calls and their perception in sulawesi macaques

Playback experiments were conducted to investigate interspecific discrimination of male loud calls in Sulawesi macaques. Loud calls of four macaque species living in Sulawesi (Macaca tonkeana, M. maurus, M. hecki, andM. nigrescens) and a control stimulus (an 8-sec frequency modulated sound) were played back to semi-free-ranging Tonkean macaques (M. tonkeana). A preliminary acoustic analysis indicated that the calls of these four species differ in some spectral and temporal features. In the playback experiments, Tonkean macaques responded in a similar manner to conspecific calls and calls of two other species,M. maurus andM. hecki. In contrast, animals responded more weakly to the call ofM. nigrescens and the control stimulus. Males responded more strongly than females to all stimuli, while females appeared to be more discriminating for species differences than males. Analyses on the acoustic features of loud calls suggested that high frequency, wide frequency range, and repetition of sound units at a high rate elicit quick responses from animals.     

Vocal communication of tonkean macaques in confined environments

Vocal recordings of one semi-free-ranging group and one captive group of Tonkean macaques (Macaca tonkeana) were used to establish the vocal repertoire of the species. Only the alpha male of the groups uttered a very distinctive loud call. Localization variants of coo calls were found. Alarm calls given by this species were acoustically similar to those by Japanese, rhesus, and long-tailed macaques (M. fuscata, M. mulatta, andM. fascicularis). Adult females uttered a specific variant of vocalizations during sexual morphological changes. The repertoire of agonistic vocalizations was more variable than that of any other macaque species investigated. These characteristics were discussed with reference to previous studies on vocalizations of macaque species.     

The study of vocal communication of wild mandrills in Cameroon in relation to their social structure

The vocal repertoire of the mandrill (Mandrillus sphinx), a forest living baboon, is described, and their vocal communication analyzed quantitatively. Although the vocal repertoire of mandrills corresponds well to that of savanna living baboons,Papio, some characteristics differed, such as the development of long-distance calls and differentiation of vocalizations between age-sex classes. Vocal communication within a group was closely related to changes in the spatial distribution of group members, and the two most common vocalizations, crowing and 2PG, appear to function as contact calls. Based on the wide dispersion of food trees, a group of mandrills divided into several feeding groups (subgroups). The two types of contact call were given in different and in some senses complementary contexts, and helped to facilitate and maintain group integration. According to their acoustic structure, these calls are long distance calls. Influenced by the high-level of attenuation of vocalization on the forest floor, the mandrill has developed them as contact calls, instead of using the contact “grunt,” which is common to the savanna living baboons. Comparing the patterns of vocal exchanges of mandrills with those of gelada and hamadryas baboons which have a multi-levelled society, the social structure of the mandrill is discussed. From the analysis of the spatial distribution of vocal emission, a number of clusters of vocalizations were obtained. These clusters correspond to subgroups. The frequent female-female and female-male vocal exchange between subgroups of mandrills suggest that the relationships between subgroups are less closed than between the one-male units of gelada and hamadryas baboons. Furthermore some of these clusters include more than two vocalizing adult males, while in other clusters there are no vocalizing adult males. Thus, the social structure of mandrills is suggested to be multi-male rather than a multilevelled type. The absence of contact calls specific for short distance and the functional replacement of the grunting of all group members by persistent emission of a loud call (2PG) by usually just one adult male suggests that the social structure of mandrills is not exactly equivalent to that of the multimale troop of savanna living baboons. Usually the use of 2PG is monopolized by one adult male travelling in the rear part of the group. Such monopolization of 2PG emission and the pattern of 2PG-2PG or 2PG-roar exchanges by adult males in some cases indicate the existence of strong dominance relationships among adult males, and especially the existence of a leader male within a multi-male group of mandrills.     

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.     

Loud calls ofGalago crassicaudatus andG. garnettii and their relation to habitat structure

Long distance vocalizations have been shown to be good indicators of genetic species in primates. Here the loud calls of two recently identified greater galago taxa —Galago crassicaudatus andG. garnettii — are compared and analyzed statistically. Observed differences in call structures are investigated further as potential indicators of differences in the structures of habitats frequented by the two species. Although the calls share a repetitive structure, and show similar dominant frequency bands (1,000 – 1,500 Hz), they differ significantly in the number of units per call, unit duration, inter-unit interval, highest frequency, lowest frequency, dominant frequency band, first harmonic, and call duration. The duration of theG. crassicaudatus call is more than twice that ofG. garnettii. Strong intraspecific consistency is seen in the most energetic frequency bands (dominant frequency band and first harmonic), and durations of the individual units and inter-unit intervals. Information important to species recognition is thus most likely to be contained in these features. Individual recognition may be encoded in the relative emphasis of higher level harmonics. The frequency structures of the calls will reflect requirements for acoustical transmission in a forest environment, as well as structural constraints imposed by body size. Higher frequencies detected in theG. garnettii call (up to 8,500 Hz) may have a functional significance related to distance estimation, or may simply be a reflection of smaller body size. The greater modulation of theG. garnettii call suggests that its habitat constitutes a denser or more turbulent medium for sound transmission than does the habitat ofG. crassicaudatus.     

Comparative study of vocal communication in two Asian leaf monkeys, Presbytis johnii and Presbytis entellus

This paper presents comparative data on the vocal communication of two Asian leaf monkeys, the Nilgiri langur (Presbytis johnii) and South Indian common langur (Presbytis entellus), based on sound recordings and behavioural observations of free-ranging groups. Spectrographical analyses revealed a repertoire of 18 basic patterns for Nilgiri langurs, and 21 basic patterns for common langurs. The repertoires of the two langur species consist of both discretely structured vocal patterns, in which alterations of the physical parameters are restricted to intra-class variation, and those in which structural variations cause integration between different sections of the repertoire. Qualitative assessments of group scans indicate that in both species vocal behaviour is characterized by pronounced sex-differences in the use of the different elements of the vocal repertoire. Comparison of data available from different populations of P. entellus suggests population-specific modifications on both structural and behavioural levels. Moreover, characteristic elements of the vocal systems of the two Asian species demonstrate striking similarities to those described for the African black-and-white colobus.     

Cytological characterization of heterochromatin and rDNA inPinus radiata andP. taeda

Fluorochrome C-banding ofPinus radiata andP. taeda metaphase chromosomes showed many pericentromeric DAPI bands and interstitial CMA bands inP. radiata, and centromeric and interstitial CMA bands inP. taeda. Giemsa C-band patterns differed between the species with centromeric bands inP. radiata but no consistent bands inP. taeda. A karyotype ofP. radiata was developed based on banding patterns that distinguished all but two of the 12 pairs of chromosomes. In situ hybridization (ISH) using probes for high-copy ribosomal DNA (rDNA) showed 10 pairs of 18S–25S sites and two pairs of 5S sites in both species. Most of the sites were interstitial or centromeric.     

Vox alouattinae: A preliminary survey of the acoustic characteristics of long-distance calls of howling monkeys

This survey of the acoustic characteristics of howling monkey loud calls, covering six of the seven members of the genus Alouattaand presenting audiospectrograms of roars from two species for the first time, suggests that the genus consists of at least two groups: a monotypic palliatagroup, including all subspecies, and a non-palliatagroup, including belzebul, caraya, fusca, pigra,and seniculus.The non-palliatagroup vocalizes continuously for sustained periods of time;their loud calls exhibit a wide bandwidth relative to the calls of the palliatagroup, with emphasized frequencies generally in the range 300- 2000 Hz. The palliatagroup does not vocalize continuously, their vocal bouts being significantly shorter than those of the non-palliataforms. The emphasized frequencies are normally restricted to 300- 1000 Hz, with little acoustic energy in higher frequencies. This bipartite classification places pigrawithin the non-palliatagroup father than with parapatric palliata,which may have important phylogenetic implications. Further, the classification suggests two modes of employing the highly derived howler vocal tract to produce loud calls within the portion of the ambient noise spectrum favorable to long- distance transmission of sound. Finally, I discuss the constraints placed by environmental acoustics on strategies for long- distance communication, hypothesized modes of vocal production, and the use of acoustic studies for phylogenetic reconstruction. Each discussion suggests projects, some already under way, that could elucidate the determinants of variations in communicative patterns within specific social and physical environments.     

A preliminary study of vocal communication in wild long-tailed macaques (Macaca fascicularis). II. Potential of calls to regulate intragroup spacing

This study is a preliminary assessment of the potential of long-tailed macaque (Macaca fascicularis) calls to operate in systems of within-group spacing. Covariation in the rate of occurrence of calls with party spread, size, and activity among wild individuals of one group suggested that four classes of calls may function in intragroup spacing. Two of them are “clear” calls of long duration and pronounced frequency modulation. Calling rate increased with party spread for low- and high-frequency variants of these calls during resting and feeding respectively, suggesting possible utility in maintenance of spatial relations over moderately long distances. A third “harsh” call was negatively correlated with party spread during foraging and may thus function to increase dispersion among foraging individuals. Another harsh call with a tonal onset was unique among all calls in the vocal repertoire in being more frequently performed by lone, isolated individuals than by macaques accompanied by others, suggesting a possible function in reestablishing contact that has been severed. The functional significance of these calls with respect to their acoustic structures is discussed. Macaques that use calls to regulate intragroup spacing can control communication distance and direction by their choice of acoustically different vocalizations. This choice may be affected not only by varying environmental constraints on sound transmission, but also by social and ecological factors such as intragroup competition.     

Interactions of thePolycomb group of genes with homeotic loci ofDrosophila

Summary Members of thePolycomb (Pc) group of genes are required for the correct determination of segment identity, and are thought to be negative regulators of thebithorax andAntennapedia complexes. This hypothesis has been tested molecularly for only some members of thePc group. Here, we examine the distribution ofUltrabithorax (Ubx),Antennapedia (Antp), andSex combs reduced (Scr) proteins in the epidermis, central nervous system, and midgut of embryos homozygous for mutations in tenPc group genes. We show that zygotic loss of mostPc group genes causes ectopic expression ofUbx andAntp, but that there are differences in time and tissue-specificity. FivePc group mutations lack midgut constrictions and also exhibit ectopic or suppressedUbx expression and suppression ofAntp expression. Distribution ofAntp is upset earlier than distribution ofUbx in the central nervous system of everyPc group mutant affecting both genes. Loss of the zygotic products ofPolycomb, extra sex combs, andAdditional sex combs cause ectopic expression ofScr in epidermis, and allPc group genes exceptPsc have suppressedScr expression in the nervous system. These results are discussed with respect to the function of thePc group.     

A preliminary study of vocal communication in wild long-tailed macaques (Macaca fascicularis). I. Vocal repertoire and call emission

Vocal communication in wild long-tailed macaques (Macaca fascicularis) is described in terms of (1) a preliminary vocal repertoire and the situations in which calls occur in the natural habitat of this species and (2) quantitative measurement of the natural occurrence of calls in the field. Although a number of calls are relatively discrete (e.g., a male loud call), gradation is pronounced for both wide-spectrum (“harsh”) and narrow-spectrum (“clear”) vocal signals. Thirteen general types of harsh calls are identified provisionally as elements of the vocal repertoire. The exact number of discrete clear calls contributing to the vocal repertoire could not be ascertained precisely, but these calls were classified operationally into six broadly acoustically different classes in order to measure natural vocal behavior. Vocalizations tended to occur in temporal “clusters” during sample, periods. Narrow-band clear or “coo” calls were more frequently performed by macaques than wide-band harsh calls. The possible functional implications of the correlated occurrence of multiple vocal signals are discussed.     

In vitro induction of multiple shoots and plant regeneration inVigna

Summary Cotyledonary nodes, excised cotyledons, and hypocotyl segments of six varieties ofVigna mungo andV. radiata have been tested for their morphogenic potential on media containing a range of hormonal combinations including benzyladenine, kinetin, thidiazuron (TDZ), and zeatin. Multiple shoots developed on cotyledonary node explants in all varieties tested on basal medium containing cytokinin. Presence of both the cotyledons, either full or half, resulted in a maximum number of shoots produced. Shoot bud regeneration was achieved via meristem formation on excised cotyledons on Murashige-skoog basal medium with B₅ vitamins supplemented with TDZ. Mature plants had normal phenotypes.V. mungo var. PS1 andV. radiata var. Pusa 105 were found to be the most responsive varieties for shoot regneration. The histology ofin vitro organogenesis was studied.     

A case of simple tool use in wild liontailed macaques (Macaca silenus)

Three members of a group of liontailed macaques (Macaca silenus) were seen to use leaves for food preparation. Other examples of prey-selection and hunting behaviour in liontailed macaques reflect individual- and group-specific skills. The absence of similar patterns in bonnet macaques (Macaca radiata) living in the same habitat might be related to differences in the social design and indicate the high significance of social aspects for the occurrence and manifestation of innovative behaviour.     

Seasonal variation of vocal behaviour in a temperate songbird: assessing the effects of laboratory housing on wild-caught, seasonally breeding birds

Many laboratories are conducting research using songbirds as their animal model. In particular, songbirds are widely used for studying the behavioural and neural mechanisms underlying vocal learning. Many researchers use wild-caught birds to conduct this research, although few studies of behaviour have been conducted to determine the effects of captive housing on these species. We investigated the vocal production pattern of wild-caught black-capped chickadees (Poecile atricapillus) over an entire season in laboratory housing. We documented the frequency of production of four vocalizations (fee-bee song, chick-a-dee calls, dee calls, and gargle calls) across seasons and diurnal pattern and compared the observed pattern of laboratory vocalizations to those previously observed and reported in the wild. Laboratory-housed chickadees had seasonal and diurnal vocal production shifts that were related to both photoperiodic changes (season) and diurnal pattern. For instance, there was significantly more fee-bee song in the spring than summer, autumn, and winter with the most fee-bee song occurring at spring dawn as seen in the wild. Our results also confirmed that the general pattern of vocalizations was consistent between wild and laboratory populations, with no significant differences for either the seasonal or diurnal pattern of fee-bee song production between populations. Differences between settings were observed in the pattern of chick-a-dee calls at dawn and sunset between field and laboratory populations. However, differences in the quantity of vocalization types between laboratory and wild populations suggest that housing conditions are influencing the normal vocal behavioural patterns.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

RFLP analysis for species separation in the generaBipolaris andCurvularia

Restriction fragment length polymorphism (RFLP) of the total DNA ofBipolaris andCurvularia species was analysed using arbitrarily chosen genomic clones of DNA fromCurvularia lunata andBipolaris maydis as probes. Clear differences among species in both genera, resulting in different banding positions, were obtained with some probe-enzyme combinations. Intraspecific polymorphism in banding positions with these probe-enzyme combinations was slight. These analyses allow discrimination between the species. DNA fingerprinting with intrageneric probes is a potentially useful tool for species separation and identification inBipolaris andCurvularia when coupled with another characteristic such as conidial morphology.Curvularia aeria comb. nov. was proposed forCurvularia lunata var.aeria on the basis of differences in RFLP banding patterns and differences in conidial morphology.     

Molecular control of early cone development inPinus radiata

Summary A family of genes expressed during early stages of shoot development were isolated fromPinus radiata. A homologue of theLEAFY/FLORICAULA flower meristem-identity genes,NEEDLY (NLY), and three MADS-box genes,PrMADS1, PrMADS2 andPrMADS3 (Pinus radiata MADS-box genes), were expressed at early stages of initiation and differentiation of reproductive (male and female) cone buds, as well as vegetative buds. Expression ofNLY in transgenicArabidopsis thaliana promoted floral fate, demonstrating that it encodes a functional ortholog of theFLORICAUL A/LEAFY genes of angiosperms.Abbreviations DSB dwarf shoot bud - LSTB long-shoot terminal bud - PCB pollen cone bud - SCB seed cone bud - LD long day - SD short day     

Evolution of thedec-1 eggshell locus inDrosophila. I. Restriction site mapping and limited sequence comparison in themelanogaster species subgroup

Summary We have analyzed 18 kb of DNA in and upstream of thedefective chorion-1 (dec-1) locus of the eight known species of themelanogaster species subgroup ofDrosophila. The restriction maps ofD. simulans, D. mauritiana, D. sechellia, D. erecta, andD. orena are shown to have basically the restriction map ofD. melanogaster, whereas the maps ofD. teissieri andD. yakuba were more difficult to align. However, the basic amount of DNA and sequence arrangement appear to have been conserved in these species. A small deletion of varying length (65–200 bp) is found in a repeated sequence of the central transcribed region ofD. melanogaster, D. simulans, andD. erecta. Restriction site mapping indicated that thedec-1 gene is highly conserved in themelanogaster species subgroup. However, sequence comparison revealed that the amount of nucleotide and amino acid substitution in the repeated region is much larger than in the 5 translated region. The 5 flanking region showed noticeable restriction site polymorphisms between species. Based on calculations from the restriction maps a dendrogram was derived that supports earlier published phylogenetic relationships within themelanogaster species subgroup except that theerecta-orena pair is placed closer to themelanogaster complex than toD. teissieri andD. yakuba.