Gonadal control of male scent in the tarmarin Saguinus fuscicollis (Callitrichidae, Primates)

Spontaneous responses to the scent marks of male Saguinus fuscicolliswere tested in experiments where the subjects received a choicebetween scent of intact males and castrated males. Male tamarinsdiscriminated between the odors of intact and castrated males,both on the basis of fresh individual scent marks and on thebasis of marks from several donors pooled in methanol. Theirdiscriminatory response to pooled odors was more pronouncedthan that to individual odors. Females discriminated betweenintact and castrated male scents only on the basis of pooledsamples. This result shows that castration causes changes inthe odor of males. The difference in the response of the tamarinsto individual scent marks as compared to pooled samples is discussedin terms of quantitative changes caused by extraction and ofindividual recognition.     

The anatomy of the circumgenital scent gland of Saguinus fuscicollis (Callitrichidae, Primates)

In the adult male Saguinus fuscicollis , the scrotal skin and the area above the root of the penis are raised in a sharply defined cushion, which extends cranially into a rectangular suprapubic pad. The circumgenital area of the adult female resembles that of the male, except that the suprapubic pad is relatively and absolutely larger. A complex glandular organ, composed of holocrine and apocrine glands, is located beneath the epidermis of the circumgenital skin. In males, specialized holocrine glands associated with hair follicles predominate. They form a layer, 2-3 mm deep beneath the epidermis. These holocrine glands have a complex alveolar structure and possess numerously branched excretory ducts. Each group of glands empties into a common duct which enters the hair follicle. In males, the apocrine glands are located predominantly at the periphery of the glandular pad and between the scrotal and perineal areas. The excretory ducts of most apocrine glands empty on to the skin surface in close spatial association with hair follicles. However, independent openings were also observed. In females, the specialized holocrine glands resemble those of males but are more frequently interspersed with apocrine glands. The apocrine glands are larger and much more numerous than in males, especially in the region of the labia majora. Gonadectomy of an adult male and female resulted in a reduction in the size of the holocrine glands but had much less effect on the apocrine glands of the scent organ. In addition, the sexual dimorphism in gland histology was retained years after castration.     

Craniometric sexual dimorphism inLeontopithecus Lesson, 1840 (Callitrichidae, Primates)

Lion tamarins are among the World's most critically endangered primates. Many studies have been produced under guidance of the International Management Committees for the preservation and management of these tamarins. Primates present morphological sexual differences in a wide range of characteristics, including cranial morphology. Studies of sexual dimorphism in the cranial morphology of theLeontopithecus are few in number and contradictory in their results. In order to check for the existence of sexual dimorphism in lion tamarins the present study analyzed 17 craniometric distances on 56 crania of three species of lion tamarins (Leontopithecus): 20L. rosalia (14 females and 6 males); 13L. chrysomelas (6 females and 7 males); and 23L. chrysopygus (8 females and 15 males). All crania are housed in the CPRJ-FEEMA collection (Primatological Center of Rio de Janeiro) and came from animals born in captivity.L. chrysopygus was more sexually dimorphic (10/17 measurements, 59%) thanL. chrysomelas (9/17 measurements, 53%) orL. rosalia (7/17 measurements, 41%). In all three species, male values are greater than the female ones, except for orbital breadth (m7) inL. rosalia. However, this distance is not sexually dimorphic in this species. This study reveals that some cranial distances, especially in the facial region, are sexually dimorphic in lion tamarins.     

Races of the emperor tamarin,Saguinus imperator Goeldi (Callitrichidae,Primates)

The two described subspecies of the emperor tamarin,Saguinus imperator imperator Goeldi andSaguinus imperator subgrisescens Lönnberg are defined and compared, the geographic range of each plotted.     

Field observations on scent-marking behaviour in saddle-back tamarins, Saguinus fuscicollis (Callitrichidae, Primates)

The scent-marking behaviour of a group of six saddle-back tamarins, Saguinus fuscicollis nigrifrons , was studied in the Amazon rain forest of north-eastern Peru. Three types of scent marking were recognized: anogenital marking, suprapubic marking and sternal marking. Anogenital marking was the most frequent type. Two or more scent-marking acts of the same or different type were generally combined into sequences. Most scent-marking was performed on branches and lianas; trunks were infrequently used. The tamarins mainly marked on horizontal or inclined substrata with diameters between 3 and 10 cm and a height between I and 10 m. The temporal distribution of scent-marking exhibited a maximum in the early morning between 06:00 and 07:00h and a minimum between 16:00 and 17:00h. The majority of scent-marking occurred in the peripheral areas of the home-range. The spatial distribution of scent-marking was correlated with the intensity of home-range use. No elevated frequencies of scent-marking were observed during intergroup encounters. The results of this field study are compared with findings from laboratory studies, and hypotheses concerning the function of scent-marking are discussed.     

Characterization of constitutive heterochromatin of Callithrix geoffroyi (Callitrichidae, Primates) by restriction enzymes and fluorochrome bands

The neotropical primate genus Callithrix comprises two groups of species, jacchus and argentata, which inhabit distinct geographical regions and manifest different fur coloration and constitutive heterochromatin (CH) markers in their karyotypes. In this investigation the CH of a representative of the jacchus group, Callithrix geoffroyi, was analysed using fluorochromes and restriction enzymes in situ. To clarify the source of the constitutive heterochromatin of both groups, the data obtained in the jacchus group were compared with those published in the argentata group obtained by the same techniques. The C-bands of C. geoffroyi (four specimens, 2n = 46) were centromeric in all chromosomes, and distally located in pairs 6 and 22. The Alu I, Hae III, Hin fI, Rsa I, Dde I, Mbo I, and Msp I restriction endonucleases and CMA3 and DAPI fluorochromes produced different bands, which allowed the characterization of four distinct types of constitutive heterochromatin in the C. geoffroyi genome. Several of these types of heterochromatin were present in the ancestor of the two groups of species, jacchus and argentata, while others originated after their cladogenesis.     

Play Behavior in Juvenile Golden Lion Tamarins (Callitrichidae: Primates): Organization in Relation to Costs

Play is a complex behavior that is widespread among vertebrates. Despite the potential benefits for the development of social, cognitive and motor skills, play behavior has costs: energy expenditure, and the risks of injury and predation. As the fitness benefits of play are presumably to be gained as adults, we expect young animals to minimize its immediate costs. Here, we describe play behavior in golden lion tamarins (GLTs) (Leontopithecus rosalia) and test cost-minimizing hypotheses. We collected data on play behavior and adult vigilance in nine groups (four wild and five supplemented, the latter deriving from a reintroduction) of wild-living lion tamarins (16 infants) in Brazil. Results showed that play occupied 3.8% of the activity budget, occurred during the hottest times of the day, and was characterized by being mainly social, involving partners of different ages, and sometimes different species. We found no differences in playing time between wild and supplemented groups. The lion tamarins played less in ‘dangerous’ substrates (canopy branches and forest floor), and more in ‘safe’ substrates (large branches and vine tangles), and favored playing in the center of the group over the periphery. The reproductive animals were vigilant during 78% of the time the infants were playing, and were mostly oriented away from the playing animals. The observed organization of play behavior suggests that juvenile GLTs minimize the risk of predation and accidental injuries, but do not seem to minimize energy expenditure and the risks of social injuries. The social-cognitive benefits acquired from experience of older partners during play may overcome the costs of the latter behavior, and because little time was spent in play, the energetic costs may be inconsequential.     

An interdisciplinary approach to measurement

This meeting had as its theme the importance of good communications between workers in different disciplines. Papers and demonstrations were presented on a range of topics as apparently unrelated as the intraocular pressure, the tension of nitrogen in blood, and the experimental production of mesothelial tumours. In his introduction Dr J C Gilson showed how these were some recent end-products of research into pneumoconiosis. The work of the Pneumoconiosis Research Unit was centred round the properties of airborne dust and the acute and long-term effects of its inhalation. Studies ranged from the immunological responses of coal workers to surveys of men in some of the world's major asbestos fields; the latter were selected on account of the exposure to dust differing from that of workers in the UK in being confined to a single type of fibre. One link between the different studies was the features of the chest radiographs. For rounded opacities these were now read using the ILO Classification which was largely developed at the Unit; Dr Gilson demonstrated a recent extension to include the irregular opacities which are associated with exposure to asbestos.     

Home range of a Geoffroy's marmoset group, Callithrix geoffroyi (Primates, Callitrichidae) in South-eastern Brazil

The home range of one group of the Geoffroy's marmoset (Callithrix geoffroyi) was studied in a fragment of the Atlantic Forest in south-eastern Brazil, between February 1993 and January 1994. The total home range was 23.3 ha and the area used in the dry season was significantly larger than that of the wet season. The smallest distance travelled by group was 480 m/day in May and the longest was 1,980 m/day in March, but with no significant differences between seasons. The total home range used for this species agrees with the ecological grouping of the genus Callithrix proposed by Rylands & Faria (1993) and may be associated with the habitat structure, the limit of the fragment and the inexistence of neighbouring groups.     

Seasonality of the activity pattern of Callithrix penicillata (Primates, Callitrichidae) in the cerrado (scrub savanna vegetation).

Two wild groups of Callithrix penicillata, the Black Pincelled Marmoset, were observed from January to September 1998, in two areas, one an area of dense scrub savanna vegetation (cerrado) and the other, a semidecidual woodland (cerrad?o), both within the boundaries of the Ecological Reserve of IBGE (Brazilian Institute of Geography and Statistics), in an environmentally protected area, the APA (Portuguese abbreviation for "environmental protected area") Gama/Cabe?a-de-Veado, Brasília, DF. The behavioral data collected during the rainy (January 15 to April 15) and dry season (June 1 to September 15) were compared. Because of the proximity to the Reserve facilities, the group from the dense scrub savanna vegetation (CD) was submitted to antropic impacts different from the group in the semidecidual woodland (CE), which was using as territory an area that had been suffering from man-made fires every two years as part of a long-term experimental project on fire impacts. The behavioral data was quantified by instantaneous cross-section ("scan sampling") every ten minutes with records of locomotion, rest, foraging for insects, use of exudate, and feeding. During the whole year, the greatest percentage of time spent by CE and CD was in foraging for insects, with 44% and 39%, respectively. It was evident when comparing the data for the two seasons that, for both groups, foraging for insects was more intense during the dry season, possibly to complement the shortage of food, and locomotion increased during the rainy season. The greater the availability and distribution of fruit in the areas, the greater the locomotion of the groups to obtain these resources. None of the other behavioral patterns, including the use of exudates, presented significant differences between the two seasons. Both groups foraged more frequently during the dry season and locomoted more during the rainy one.     

Restriction enzyme and fluorochrome banding analysis of the constitutive heterochromatin of Saguinus species (Callitrichidae, Primates)

Metaphases of Saguinas fuscicollis fuscicollis and Saguinas mystax were subjected to restriction enzyme banding (Alu I, Hae III, Hin fI, Rsa I, Dde I, Mbo I and Msp I) and sequenced C-banding, together with fluorochrome staining (CMA3 and DAPI). Both species showed large C-bands in the pericentromeric regions. S. f. fuscicollis also manifested distal C-bands in both arms of pair 5 and in the short arms of pairs 8-15. In each species the heterochromatin revealed different reactions to the restriction enzymes and fluorochromes. This was related to its location in the genome (centromeric, pericentromeric, distal), making possible the identification of distinct categories of constitutive heterochromatin. In S. f. fuscicollis there were at least five types, namely centromeric in bi-armed chromosomes, centromeric in acrocentrics, pericentromeric, distal, and cryptic bands, detected only with the Alu I. There were three types in S. mystax, viz centromeric in bi-armed chromosomes, centromeric in acrocentric, and pericentromeric chromosomes. Several aspects of their constitution and origin are discussed.     

Mitochondrial COII gene sequences provide new insights into the phylogeny of marmoset species groups (Callitrichidae,Primates)

Mitochondrial cytochrome oxidase II (COII) gene sequences (549 base pairs) were used to investigate the taxonomic relationships among 12 marmoset (Callithrix, Cebuella and Mico) taxa. A large number of substitutions were found in the third base codon positions, providing a strong phylogenetic signal in a gene coding a conserved protein. Despite the significant affinity between the 2 Amazonian genera Cebuella and Mico, found in recent molecular studies, the analysis presented here did not resolve convincingly the phylogenetic relationships between the 3 genera. Mico nevertheless formed 3 distinct clades, reflecting a basic division of species groups based on geographic distribution (east or west of the Rio Tapajós) rather than morphology (presence or absence of auricular hair). This supports the taxonomic distinction of the allopatric emiliae forms. In Callithrix, Callithrix aurita forms a distinct clade, but the remaining morphotypes form a somewhat contradictory cluster, possibly resulting from an extremely rapid radiation.     

Feeding ecology of Saguinus bicolor bicolor (Callitrichidae: Primates) in a relict forest in Manaus, Brazilian Amazonia.

This study is part of a long-term ecological study of habitat and dietary requirements of the pied bare-face tamarin (Saguinus bicolor bicolor). One group was studied for 11 months in an area of secondary forest in a suburb of Manaus, Amazonas, Brazil. Three main vegetation types occurred inside the group's home range (12 ha): capoeira, older secondary forest and campinarana (white sand forest). The tamarins ate fruits (21 species), flowers (1 species), exudates (4 species), and arthropods (insects and spiders). They spent 14.3% of total activity time seeking and eating animal prey, and 9.9% feeding on plant material, mostly fruits. In general, fruits consumed were ripe, small and succulent. Trees used for feeding were low and had small crown diameters. Three plant species (Protium aracouchinni, Myrcia cf. fallax, and Couma utilis) were used intensively during the three seasons covered by the study period. The concentrated use of 3 fruit species, each for an extended period (one fruiting species per season), provided the tamarins with a regular food supply. Tamarins consumed exudates from holes in the bark of trees of the families Anacardiaceae and Vochysiaceae, as well as gum exuded from seed pods of Mimosaceae. Exudates were exploited during the dry season and at the beginning of the wet season. Group travel was primarily based on routes connecting the fruiting trees exploited, with foraging for animal prey occurring during travel. Tamarins searched for arthropods on trunks, branches and leaves and in trunk holes. The foraging and feeding tactics displayed by S. b. bicolor are closely linked to morphological characteristics (small size and weight, claw-like nails) that allowed access to energy-rich resources (arthropods and plant exudates) in different strata of the vegetation.     

Karyotypic comparison among Cebuella pygmaea,Callithrix jacchus and C. emiliae (Callitrichidae,Primates) and its taxonomic implications

The karyotype of Cebuella pygmaea (2n=44) obtained by G-, C-banding, and NOR-staining is described. This species presents a heteromorphic C band in the intersticial region of the short arm of chromosome 2. The data obtained were compared with those previously described for the karyotypes of Callithrix jacchus and Callithrix emiliae. The three species differ in the amount and distribution of non-centromeric constitutive heterochromatin. The importance of the variation in constitutive heterochromatin for the phylogeny of the group is discussed. Comparison of the karyotypes in terms of G-banding patterns showed that C. pygmaea and C. emiliae differ from C. jacchus by a Robertsonian translocation and a paracentric inversion, whereas C. pygmaea and C. emiliae differ from each other by a reciprocal translocation between an acrocentric autosome and the short arm of the submetacentric chromosomes that distinguishes their karyotypes from that of C. jacchus. The possible evolutionary paths followed by the karyotypes of the three species are discussed.     

Karyotype of Callithrix mauesi (Callitrichidae,Primates) and its relations with those of C. emiliae and C. jacchus

A study was conducted on the most recently described marmoset species, Callithrix mauesi, and the results obtained were compared to those previously reported for the karyotypes of C. jacchus and C. emiliae. No mechanism of chromosome rearrangement differentiates the karyotypes of C. mauesi (2n = 44) and C. emiliae (2n = 44), which diverge from C. jacchus (2n = 46) by a Robertsonian translocation and a paracentric inversion. C. mauesi, like C. emiliae, presents telomeric constitutive heterochromatin in various chromosomes, forming large heterochromatic blocks in some. This does not occur in C. jacchus, which basically presents centromeric constitutive heterochromatin. The karyotype of C. mauesi differs from that of C. emiliae only by the amount and distribution of this telomeric constitutive heterochromatin. One of the chromosomes presenting a heterochromatic block in C. mauesi is chromosome X, a fact not previously reported in the Order Primates. The present chromosome data show that C. mauesi is closer to C. emiliae than to C. jacchus, in agreement with its inclusion in the C. argentata group. In the present paper, we describe for the first time, at the chromosome level, chimerism between fraternal twins of the same sex (XY/XY), with the heterochromatic block of pair 2 being the marker. © 1994 Wiley-Liss, Inc.     

A New Subspecies of <Emphasis Type="Italic">Saguinus fuscicollis</Emphasis> (Primates,Callitrichidae)

Saddleback tamarins (Saguinus fuscicollis, S. melanoleucus, and S. tripartitus) occur in the upper Amazon, west of the rios Madeira and Mamoré–Guaporé to the Andes. They currently comprise 13 species and subspecies in Bolivia, Brazil, Colombia, Ecuador, and Peru. Here we report on a previously undescribed subspecies of Saguinus fuscicollis from the interfluvium of the lower rios Madeira and Purus in the central Amazon of Brazil. It is a distinct form with a very pronounced mottling on the back giving the appearance of a saddle, a characteristic shared by the 3 species, and the reason for their collective common name. The lack of a white superciliary chevron and its highly mottled ochraceous-dark brown to black saddle that extends from the scapular region to the base of the tail distinguish the new taxon from Saguinus fuscicollis weddelli. The latter characteristic also distinguishes it from another saddleback tamarin (Saguinus fuscicollis ssp.) that has been reported immediately to the south of its range in the same interfluvium. We compare pelage coloration, external characters and craniometric measurements with its geographically closest relatives, Saguinus fuscicollis weddelli and S. f. avilapiresi, and indicate its probable geographic distribution in a small area between the rios Madeira and Purus, just south of the Rio Amazonas.     

Sleeping habits of tamarins, Saguinus mystax and Saguinus fuscicollis (Mammalia; Primates; Callitrichidae), in north-eastern Peru

The sleeping habits of moustached tamarins, Saguinus mystax , and saddle-back tamarins, Saguinus fuscicollis , were studied in northeastern Peru. Five types of sleeping sites were distinguished: 1) Jessenia bataua palms; 2) tree hollows; 3) dense tangles of vegetation; 4) crotches; 5) open horizontal branches. Both tamarin species used Jesseniu-palms most frequently. Tree hollows ranked second in the saddle-back tamarins, but were never used by moustached tamarins. Sleeping sites of moustached tamarins were located significantly higher than those of saddle-back tamarins. Jessenia -palms used by moustached tamarins were significantly higher than palms from a random transect sample, but this was not the case for Jessenia -palms used by saddle-back tamarins. For both species, concealment seems to be more important than height above ground. The maximum number of subsequent nights spent in the same sleeping site was two in moustached tamarins and six in saddle-back tamarins. The two tamarin species did not compete for sleeping sites. While the general pattern of sleeping site selection conforms to hypotheses predicting safety from predators as a major factor, differences between the two tamarin species reflect general niche differences between them. Most sleeping sites are located in exclusively used parts of the home range. Moustached tamarins generally use sleeping sites that are close to the last feeding site of the afternoon. The distance between simultaneously used sleeping sites of moustached and saddle-back tamarins are generally close together, which helps to minimize time spent out of interspecific association.     

Floral scent and intrafloral scent differentiation inMoneses andPyrola (Pyrolaceae)

Floral scent was collected by headspace methods from intact flowers, petals, and stamens of four species ofPyrolaceae. The scent samples were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The floral scent inPyrola spp. is differentiated into a characteristic petal scent—phenyl propanoids and a characteristic stamen scent—methoxy benzenes. InMoneses the scent is characterized by isoprenoids and benzenoids, with a larger proportion of benzenoids in the stamens compared to the petals. Specific anther scents may promote foraging efficiency in buzz-pollinated species and enhance flower fidelity. Variation in floral scent composition is consistent with the taxonomic relationships among the genera and species examined.