Geographic Distribution of Red Howlers (Alouatta seniculus) in Southwestern Brazilian Amazonia, with Notes on Alouatta caraya

We surveyed howler (Alouatta) populations at 36 sites throughout the Brazilian state of Rondônia, in southwestern Amazonia, using quantitative (line transect surveys) and qualitative (interviews) methods. We recorded the red howler (Alouatta seniculus) at only one- third of the sites, and the species was relatively rare at most of them, especially in comparison with sympatric atelids (Ateles chamek and Lagothrix cana). In addition to local discontinuities, Alouatta was absent from a wide area (possibly as much as 100,000 km²) of northern Rondônia, south of the upper Madeira river. This lacuna apparently contradicts the typical association of the species with flooded forest ecosystems, but the ecological factors that may underlie it remain unclear. Competition with sympatric atelids does not appear to be a significant factor anywhere within the study area. Also, there is no evidence to suggest that the distribution patterns are related to recent human colonization of the state. We collected indirect evidence of the presence of a second howler species – Alouatta caraya – at two sites in southern Rondônia, where they are associated with highland savanna habitats and gallery forests in the Guaporé grasslands.     

Arboreal Quadrupedism and Forelimb Articular Anatomy of Red Howlers

I describe the patterns of forelimb movements that facilitate adult red howling monkeys (Alouatta seniculus) to advance quadrupedally on arboreal trails in directions ± 45° from the horizontal, the articular surface morphology at the scapulohumeral and elbow joints, and the structure of the trails. Results indicate (1) that red howlers splay their forelimbs when advancing on arboreal trails of mesh-like substrates, but they do not splay them to proceed on unilineal arboreal trails, and (2) that the articular surfaces are adapted to enable the scapulohumeroulnar bony alignments that result in both splayed and nonsplayed forelimb motions. These results have implications for the locomotor habits of several fossil catarrhines.     

New species of Justicia (Acanthaceae) from the Guianas

Four new species,Justicia oldemanii, J. mcdowellii, J. wilhelminensis, andJ. prevostiae are described, illustrated, and compared with their closest relatives. A key to species ofJusticia from the Guianas is also provided.     

New species of Hiraea (Malpighiaceae) from the Guianas and adjacent Brazil

Four species of Hiraea are described and discussed:H. gracieana andH. morii from Saül, French Guiana,H. longipes from the Oyapock region of French Guiana and Amapá, Brazil, andH. propinqua from French Guiana and Suriname.Hiraea gracieana is illustrated.     

Relation of Intergroup Variation in Allogrooming to Group Social Structure and Ectoparasite Loads in Red Howlers (Alouatta seniculus)

We compare the allogrooming behavior of 5 troops (average size = 8.2) of red howlers (Alouatta seniculus) from the Venezuelan Llanos with that of other A. seniculus and Alouatta spp. of the genus. In 126.9 observation hr, we recorded 118 allogrooming events, with an average bout length of 109 sec. Females groomed more frequently than males did, but as groomees there is no significant differences between sexes. Adult males groomed adult females mostly in a sexual context (before copulation). Allogrooming rates differ significantly among groups. There are also significant differences among members of the same troop both as groomers and groomees, which we explain in the context of the social behavior and history of each troop. There is no significant correlation between weight of the groomee and duration of the grooming bout. However, the examination of grooming rates and ectoparasite load suggests that allogrooming may have hygienic consequences. Differences in allogrooming rates among species of Alouatta are related to differences in group kin structure and patterns of female competition, in particular, coalition formation. We conclude that the social structure and the degree of relatedness among individuals within a group (or among individuals in a population in interpopulation comparisons) is a more important determinant of allogrooming rate than body size or group size. Our results emphasize the importance of considering intergroup and interpopulational variation in behavior.     

Adoption in free-ranging red howler monkeys,Alouatta seniculus of Venezuela

This report describes three cases of infant adoption in red howler monkeys (Alouatta seniculus) of Venezuela. In one case, a lactating female adopted her infant granddaughter after the infant's mother disappeared and the infant survived for the next 25 months. In the second case, an adult female adopted her infant granddaughter for nine days while the infant's mother was still a group member. In the third case, a nulliparous female temporarily adopted an infant from a neighboring group. The details and the possible reasons for these adoption are described.     

Antipredator Behavior of Brown Howlers Attacked by Black Hawk-eagle in Southern Brazil

In field studies between 2002 and 2004 in southern Brazil, we recorded antipredatory behaviors (N=9) of brown howlers (Alouatta guariba clamitans) under attack by the black hawk-eagle (Spizaetus tyrannus). We observed 2 types of behavioral responses: the descent to the understory followed by the dispersion of the group and immobility and silence. Brown howlers displayed behaviors specific to evading aerial predators, which are similar to the ones in other Neotropical primates.The article is contribution number 1578 of Departamento de Zoologia, Universidade Federal do Paraná     

Estimation of the retention times and distances of seed dispersed by two monkey species, Alouatta seniculus and Lagothrix lagotricha, in a Colombian forest

Isolated-bout method to estimate the retention times and dispersal distances was applied to the seed dispersal by red howler monkeys (Alouatta seniculus) and Humboldts woolly monkeys (Lagothrix lagotricha) in a lowland tropical forest at La Macarena, on the border of the Macarena and Tinigua National Parks, the Department of Meta, Colombia. Continuous observations were made on the feeding and ranging behavior of well-habituated troops of howler monkeys and woolly monkeys as well as continuous collection of monkeys feces. We selected out the isolated-bout as a feeding bout on the specific species that was only once recorded within 48 h before the seeds of that species appeared in the feces of monkeys. In that case, the seeds were strongly suggested to come from that isolated bout. Then retention times, route seed dispersal distances and direct seed dispersal distances were estimated. Howler monkeys, which are regarded as generalist herbivores, showed longer retention times and dispersal distances along monkeys route than did woolly monkeys, which are specialist frugivores. However, the direct distances that seeds were carried from the mother tree were not significantly greater for howler monkeys than for woolly monkeys. This shows that both retention time and movement patterns by the monkeys, especially the total ranging area, influence the direct distance that seeds are carried from the mother tree.     

Three new species of <Emphasis Type="Italic">Elaphoglossum</Emphasis> (Dryopteridaceae) from the Guianas

Three new species of Elaphoglossum are described from the Guianas: E. arachnidoideum, E. boudriei, and E. cremersii.     

Notes on the geographic distribution of howling monkeys in the marajó archipelago, pará, Brazil

I review the distribution of genus Alouattain the Marajó Archipelago based on geographic variation of pelage color patterns. Specific differences exist among the labeled specimens at Museu Paraense Emílio Goeldi, which are confirmed via new field information from wild populations. The animals from Marajó, Caviana, and Mexiana Islands possess color patterns of Alouatta belzebul,while Alouatta seniculusis confirmed as the species that inhabits Gurupá Island. The high variability of pelage coloration of the animals from Marajó, Caviana, and Mexiana Islands includes all phenotypes formerly designated as different subspecies. The howler populations from these three islands belong to the same subspecies as those populations that inhabit the region of Tucurui dam reservoir (area 4). Finally, it seems that, as also suggested by chromosome studies, A. belzebulprobably comprises different epiphenotypes without taxonomic validity.     

Nomenclature,redescription, and new record from Okinawa of Cymbasoma moriiSekiguchi,1982 (Monstrilloida)

In 1990 and 1991 the distribution of the genus Gammarus was examined in the River Hunte and its tributaries (Lower Saxony, northern Germany). In contrast to data from the literature, Gammarus fossarum and G. roeseli were just as abundant as G. pulex, which had been known to inhabit rivers and brooks in northern Germany. G. pulex was most frequent (1900 at 57 out of 70 and 1991 at 37 out of 39 sampling sites) followed by G. fossarum (at 52 and 32 sampling sites, respectively), whereas G. roeseli was locally restricted (at 7 and 6 sampling sites, respectively). G. fossarum and G. pulex were distributed up to the level of the city of Oldenburg; further north their distribution is limited by tidal influences and they are replaced by G. zaddachi. The possibility of using gammarids as indicators of water quality, as it has been done in low mountain ranges, is discussed.     

Diet of the red howler monkey (Alouatta seniculus) in French Guiana

We report the feeding behavior and food preferences of a troop of red howler monkeys (Alouatta seniculus) over two annual cycles in primary tropical rain forest in French Guiana. The monkeys used 195 plant species from 47 families as food. Major food categories were young leaves (54%), mature fruits (21.5%), and flowers (12.6%). Other food categories included old leaves, immature fruits, termitarium soil, bark, and moss. The monkeys were less selective than other howler groups, since 19 plant species contributed 1% to their diet and accounted for only 35.7% of their total diet. The Sapotaceae was the most frequently eaten plant family and represented >10% of the total diet.     

Two new species ofHalicyclops (Copepoda,Cyclopoida) from the Amazon Basin,Brazil

Two new species ofHalicyclops are described from plankton samples taken in two localities in the Amazon River mouth area, State of Pará, Brazil.Halicyclops lindbergi sp.n. resemblesH. hurlberti andH. clarkei from which it differs by a combination of characters in leg 5, the anal pseudoperculum and the caudal rami. The other new species,H. dussarti, is most morphologically similar toH. pilosus, but they are separated by differences in legs 1 and 5 as well as in the ornamentation of the middle caudal setae.     

Sponge-dwelling Fishes of Northeastern Brazil

In this first attempt to survey the Brazilian sponge-dwelling fishes we present a list of collected fishes, with notes on their distribution, abundance and habitat preferences. Risor ruber, an obligate sponge-dwelling goby, and Scorpaenodes tredecimspinosus, never before collected in association with sponges, are recorded for the first time in the western South Atlantic based on collections made in localities on the northeastern Brazilian coast. Previous work on Risor ruber indicated that it preferred massive sponges, but in our study the majority of the specimens were found in the lumen of tubular sponges, Aplysina lacunosa, together with other fishes and invertebrates, mostly crustaceans. Elacatinus figaro, originally described as a cleaner goby, is also a sponge-dweller that occurs in waters much deeper than previously thought. The sponge community off northeastern Brazil represents the only shelter for several species of fishes in a desert of rubble and flat rocky bottoms, perhaps functioning as habitat oases. We also found four Brazilian endemic species of fishes associated with sponges in depths greater than 50m, which contradicts a previous hypothesis suggesting that endemic fishes in Brazilian coastal waters are restricted to depths less than 50m.     

Animal rhinosporidiosis in Brazil. Report of three additional cases

Fifteen cases of animal rhinosporidiosis seen in Brazil are briefly reviewed. Additional cases of the disease in two horses and one mule are reported.     

Seed dispersal by red howling monkeys (Alouatta seniculus) in the tropical rain forest of French Guiana

A 2-year field study of the frugivorous diet of a howling monkey troop, in a tropical rain forest in French Guiana, shows that they disperse by endozoochory ≥95% of plant species from which they eat ripe fruit. Passage through the digestive tract of howlers does not significantly modify the germination success of most plant species samples. Their low digestion rate (X = 20 hr 40 min) is the ultimate cause of a bimodal defecation rhythm that results in the concentration of 60% of defecations being deposited under sleeping sites. The distance of seed dispersal can reach more than 550 m from parent trees,with a mean of 260 m. Although howling monkeys consume fruits differing in morphological characteristics, they are particularly able to disseminate seeds of species whose fruits have a hard and indehiscent external coat or large seeds or both. In French Guiana, they may be especially important dispersers of the Sapotaceae with fruits that simultaneously present both characteristics.     

Morphological analysis ofAlouatta seniculus species group (Primates,Cebidae). A comparison with biochemical and karyological data

Fifteen cranial measurements were taken from wild caught specimens ofAlouatta seniculus seniculus, A. s. stramineus andA. s. macconnelli. A morphological analysis showed sex dimorphism in these three groups. A multivariate analysis discriminated among these taxa; males being more clearly discriminated than females. Our data showed that these taxa can be separated on the basis of quantitative cranial traits, biogeographic distribution, karyological differences, and biochemical characters. We therefore propose a new taxonomic arrangement, changing their taxonomic status to the species level (Alouatta seniculus, A. macconnelli, andA. stramineus).     

A new southern limit for the distribution ofAlouatta caraya in Rio Grande do Sul State,Brazil

The discovery of two groups of the black howler monkey,Alouatta caraya, inhabiting two orchards on a cattle farm, Fazenda Casa Branca (29°56′S, 55°59′W), Rio Grande do Sul State, Brazil, represents a new southern limit for the geographic distribution of this species.