Kenneth E. Glander

Dispersal patterns in Costa Rican mantled howling monkeys

Both male and female juveniles disperse in Costa Rican mantled howling monkeys (Alouatta palliata). 79% of the males and 96% of the females leave their natal groups. Males may spend up to 4 years and females up to 1 year as solitaries. Extra-group individuals are faced with only three possibilities, i.e., form a new group by joining another extra-group individual, join an established social group, or remain solitary. Most surviving extra-group individuals join an established social group which contains no kin. Females join with the help of a resident male and once in a group proceed to rise to the alpha position through dyadic interactions. The immigrant female either becomes the alpha female or leaves and tries again in another group. Males challenge the alpha male and either defeat him or remain solitary. Competition with relatives for limited high quality food may be the reason for both sexes leaving their natal groups in howlers. By leaving, the successful immigrants increase their mothers inclusive fitness while suppressing the fitness of nonrelatives instead of remaining natal and competing with relatives for limited food.

Field methods for capture and measurement of three monkey species in Costa Rica.

A total of 54 free-ranging monkeys were captured and marked in Santa Rosa National Park, Costa Rica, during May 1985, and an additional 17 were captured during March 1986. The animals were darted using a blowpipe or a CO2 gun. The drugs used were Ketaset, Sernylan and Telazol. Ketaset was effective for Cebus capucinus but unsuccessful for Alouatta palliata and Ateles geoffroyi. Sernylan was successful for A. geoffroyi and A. palliata but is no longer commercially available. Telazol proved to be an excellent alternative capture drug for both A. palliata and A. geoffroyi.

Morphometrics and testicle size of rain forest lemur species from southeastern Madagascar

Abstract Six species of prosimians inhabiting the montane rain forest of the Ranomafana National Park located in southeastern Madagascar were captured, weighed, and measured during the months of May or June of 1987, 1988, and 1989. There were no significant differences in body weights and measurements between male and female Eulemur rubriventer (red-bellied lemur) or Eulemur fulvus rufus (red-fronted lemur). Adult female Propithecus diadema edwardsi (Milne Edwards sifaka) were heavier than males but the difference was not significant. A few Avahi laniger laniger (woolly lemur), Hapalemur aureus (golden bamboo lemur) and H. g. griseus (gentle bamboo lemur) also were captured and measured. Body weights of the same individual adult P. d. edwardsi changed over the three years, suggesting variation in food availability. Although there was no difference in body weight among adult males of two groups of P. d. edwardsi , one male in each group had a testicular volume four times larger than that of other males, even though these measurements were taken five months after the breeding season. These data suggest that only one adult male mates in each group. Testicular size of the polygynous E. f. rufus males was significantly larger than that of the monogamous E. rubriventer .

Lemur diversity in Madagascar

A basic understanding of the taxonomy, diversity, and distributions of primates is essential for their conservation. This review of the status of the taxonomy of lemurs is based on a 5-d workshop entitled “Primate Taxonomy for the New Millennium,” held at the Disney Institute, Orlando, Florida, in February 2000. The aim is not to present a taxonomic revision, but to review our current understanding of the diversity and current and past ranges of lemurs and indicate where there is controversy, discrepancy, or lack of knowledge. Our goal therefore is to provide a baseline for future taxonomic investigation, as well as a clearer focus for research and conservation priorities. We here focus on the lemurs of Madagascar and recognize 5 families, 15 genera, and 99 species and subspecies. We list 39 species of lemurs described since 2000: 2 dwarf lemurs, Cheirogaleus; 11 mouse lemurs, Microcebus; a giant mouse lemur, Mirza; a bamboo lemur, Hapalemur; 17 sportive lemurs, Lepilemur; and 7 woolly lemurs, Avahi. Taxonomic revisions have resulted in the resurrection of a further 9 taxa. However, the figures do not represent the total diversity of Malagasy lemurs because more new species are being identified via new field studies and accompanying genetic research, and should be described in the near future.

Calibrating single-ended fiber-optic Raman spectra distributed temperature sensing data.

Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installations. The new methods presented are more accurate than the instrument-calibrated data, achieving accuracies on the order of tenths of a degree root mean square error (RMSE) and mean bias. Effects of localized non-uniformities that violate the assumptions of single-ended calibration data are explored and quantified. Experimental design considerations such as selection of integration times or selection of the length of the reference sections are discussed, and the impacts of these considerations on calibrated temperatures are explored in two case studies.

Parasites of Wild Howlers (Alouatta spp.)

A literature review of howler parasites provides the basis for an overview of the ecological significance of parasite surveys in primates. Within this framework, we have added insights into the interactions between primate hosts and their parasites from a long-term study in Costa Rica. We collected fecal samples from mantled howlers (Alouatta palliata) over a 9-year period (1986–1994 inclusive) and analyzed them for parasite eggs, larvae, cysts, and oocysts. We found many misperceptions inherent in the typical methodology of primate parasite surveys and in the reporting of the findings. Our work in Costa Rica suggests that a snapshot effect occurs with most surveys. A static view does not reflect the dynamic and changing ecological interaction between host and parasite. We describe some problems with parasite data analyses that emphasize the need for long-term longitudinal surveys in wild primate groups.

A coprological survey of parasites of wild mantled howling monkeys, Alouatta palliata palliata.

Fecal samples from 155 mantled howling monkeys (Alouatta palliata palliata) examined at Centro Ecologico La Pacifica, Guanacaste Province, Costa Rica, revealed 75 (48%) had parasitic infections. A sampling of nine howling monkeys from Santa Rosa National Park, Costa Rica indicated only one infected animal (11%). Only three of 19 (16%) spider monkeys (Ateles geoffroyi) also from Santa Rosa were infected. Controrchis biliophilus, Trypanoxyuris minutus, unidentified strongylid eggs and Isospora sp. oocysts were found. Three monkeys from La Pacifica died and were examined for adult helminths. They were infected with Ascaris lumbricoides, C. biliophilus and T. minutus.

Captivity humanizes the primate microbiome

Significance Trillions of bacteria live in the primate gut, contributing to metabolism, immune system development, and pathogen resistance. Perturbations to these bacteria are associated with metabolic and autoimmune human diseases that are prevalent in Westernized societies. Herein, we measured gut microbial communities and diet in multiple primate species living in the wild, in a sanctuary, and in full captivity. We found that captivity and loss of dietary fiber in nonhuman primates are associated with loss of native gut microbiota and convergence toward the modern human microbiome, suggesting that parallel processes may be driving recent loss of core microbial biodiversity in humans. The primate gastrointestinal tract is home to trillions of bacteria, whose composition is associated with numerous metabolic, autoimmune, and infectious human diseases. Although there is increasing evidence that modern and Westernized societies are associated with dramatic loss of natural human gut microbiome diversity, the causes and consequences of such loss are challenging to study. Here we use nonhuman primates (NHPs) as a model system for studying the effects of emigration and lifestyle disruption on the human gut microbiome. Using 16S rRNA gene sequencing in two model NHP species, we show that although different primate species have distinctive signature microbiota in the wild, in captivity they lose their native microbes and become colonized with Prevotella and Bacteroides, the dominant genera in the modern human gut microbiome. We confirm that captive individuals from eight other NHP species in a different zoo show the same pattern of convergence, and that semicaptive primates housed in a sanctuary represent an intermediate microbiome state between wild and captive. Using deep shotgun sequencing, chemical dietary analysis, and chloroplast relative abundance, we show that decreasing dietary fiber and plant content are associated with the captive primate microbiome. Finally, in a meta-analysis including published human data, we show that captivity has a parallel effect on the NHP gut microbiome to that of Westernization in humans. These results demonstrate that captivity and lifestyle disruption cause primates to lose native microbiota and converge along an axis toward the modern human microbiome.

DENTAL MICROWEAR AND DIET IN A WILD POPULATION OF MANTLED HOWLING MONKEYS (Alouatta palliata)

The mantled howling monkey (Alouatta palliata) was the subject of the first naturalistic study of nonhuman primate behavior - Carpenter’s classic 1934 work in Panama. That study not only set the stage for future naturalistic behavioral-ecological work, it also set the tone for our perceptions of howling monkeys. For 40-50 years, howlers were essentially viewed as humid tropical forest leaf-eaters. It is only within the past 20-25 years that researchers have begun to appreciate the ecological variability and adaptability of howlers. Now, based on the work of Crockett, Glander, Milton, and others, researchers have gained a more realistic picture of howlers as folivorous frugivores which can inhabit a wide range of habitats including rain forests, swamp forests, and semideciduous forests (Crockett — Eisenberg, 1986). In fact, they are so adaptable that they are often the first neotropical primates to colonize new patches of secondary forest.

HOWLING MONKEYS AND LEAF-CUTTING ANTS - COMPARATIVE FORAGING IN A TROPICAL DECIDUOUS FOREST

Foraging by mantled howling monkeys (Alouatta palliata) and leaf-cutting ants (Atta colombica) is compared with regard to plant species harvested, plant parts harvested, statistical patterns in foraging effort, seasonal variation in foraging effort, daily foraging patterns, and foliage height attacked. This comparison is possible because intensive, year-long studies of foraging by three colonies of A. colombica and by a group of A. palliata were conducted in the same study area (Hacienda La Pacifica) in the Guanacaste Province of Costa Rica. The results show that howling monkeys and leaf-cutters differ in each of the categories mentioned above, yet share many foraging patterns. Both organisms are generalist herbivores, but are also selective. Both leaf-cutters and howlers harvest a variety of plant parts including mature leaves, new leaves, fruit, and flowers, and both cut more mature leaves and fruit in the rainy season and more new leaves and flower parts in the dry season. Both organisms prefer new leaves to mature leaves if given a choice. Nevertheless, howling monkeys and leafcutters prefer different plant species. Of seven rank correlations between monkey and ant preferences, three were negative, and the best positive correlation was 0.100, which was not significant. In addition, based on yearly averages, howlers harvest more new leaves and fruit and fewer mature leaves than do leaf-cutters. These results are compared with recent theoretical predictions concerning feeding behavior in generalist herbivores. THE PURPOSE OF THIS PAPER iS to compare foraging in mantled howling monkeys (Alouatta palliata) and leaf-cutting ants (Atta colombica). This comparison is possible because intensive, year-long studies of foraging by three colonies of A. colombica and by a group of A. palliata were conducted in the same study area in the Guanacaste Province of Costa Rica by Rockwood (1972, 1973a, 1975, 1976) and by Glander (1975a, 1975b, 1977). While it might appear unusual to compare foraging in two such different animals, there are compelling reasons to do so. Howlers and leaf-cutters are both generalist herbivores that cooccur throughout most of the-neotropics (Moynihan 1976; Weber 1966, 1972). They are generalist herbivores in the sense that they consume quantities of material from many plant species. For example, Glander (1975a) found that howlers sampled 61 of 96 (63.5%) tree species present in their home range, while Rockwood (1972, 1976) found that a colony of A. colombica gathered material from 47 of 70 (67.1 %) woody species present in their foraging area. At the same time, both howlers and leaf-cuters are selective. Glander (1975a, 1977) found that howlers spent 75 percent of their feeding time in only 88 of 1699 trees present in the habitat. Rockwood (1976) has demonstrated similar selectivity in both A. colombica and A. cephalotes. In three colonies of A. colombica studied, 80-90 percent of the mature leaves cut by each colony were selected from 10 plant species out of the 57-62 species available in a foraging area. Similarly, in three A. cephalotes colonies, the top six plant species of 36-44 available to each colony accounted for 82-95 percent of mature leaves cut. Howlers and leaf-cutters both harvest flower and fruit pieces and show decided preferences for new versus mature leaves. These preferences show seasonal patterns. Finally, both species depend on mutualistic relationships for digestion of the vegetation they consume. Howling monkeys have the usual mammalian intestinal flora and depend to an unknown degree on fermentation of their food in an enlarged caecum. Colonies of Atta feed on a fungus which is cultured on vegetation brought into the nest by the ants. Thus, while howling monkeys and leaf-cutting ants are not closely related in an evolutionary sense, they appear to have converged ecologically as generalist herbivores in neotropical forests. Since both howlers and Atta colombica forage mainly in the forest canopy they may be important interspecific compe-