bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patterns of Richness and Abundance in a Tropical African Leaf‐litter Herpetofauna1
Authors: Vonesh James R. 
Published: March 2006

ABSTRACTI compared species richness and habitat correlates of leaf‐litter herpetofaunal abundance in undisturbed and selectively logged forests, and an abandoned pine plantation in Kibale National Park, Uganda. I sampled 50 randomly located 25 m2 litter plots in each area during the wet and dry seasons in 1997. Ten anuran, five lizard, and three snake species were captured in plots over the study. Assemblage composition was most similar at logged and unlogged sites. The logged forest herpetofauna had higher species richness and abundance than the unlogged forest, but diversity was greater in the unlogged forest due to greater evenness. In contrast, the pine plantation site had the highest richness, abundance, and evenness of the three study sites, but species composition was distinct from the other areas. Herpetofaunal densities were significantly lower in all three areas during the dry season than in the wet season. During the dry season, soil moisture, litter mass, topography, shrub cover, and number of fallen logs were significant positive predictors of herpetofaunal presence in litter plots, but only soil moisture was significant in the wet season. The interaction of moisture and topography appears to be important in determining seasonal patterns of litter herpetofaunal distribution. Comparison of litter herpetofaunal studies across the tropics have shown that mid‐elevation faunas generally support fewer species than lowland faunas. Compared with other tropical mid‐elevation litter faunas, Kibale supports an intermediate number of species, but at lower densities than observed at any other mid‐elevation site reported in the literature.
Landscape Patterns of Tropical Forest Recovery in the Republic of Palau1
Authors: Endress Bryan A. , Chinea J. Danilo 
Published: March 2006

ABSTRACTA GIS (geographic information systems) database was constructed from aerial photographs, a vegetation map, and topographic map data of the Ngeremeduu Bay Drainage Area (NBDA), Palau, to examine relationships between upland land cover dynamics, environmental variables, and past land use. In 1992, 82.9 percent of the NBDA was forest, 16.6 percent was grassland, and 0.5 percent consisted of village areas. Between 1947 and 1992, there was a 11.2 percent reduction of grassland area primarily due to a 10.9 percent increase in forest cover. These land cover changes led to larger, more continuous stretches of forest and numerous, highly fragmented grassland patches. Significant relationships (P 0.001) were found between the spatial distribution of forest and grassland cover and slope, elevation, soil pH, and percent soil organic matter. These patterns, however, may have resulted from past farm site selection rather than from ecological relationships. Our results indicate that areas of forest expansion were significantly (P 0.001) associated with the location of abandoned agricultural communities. In addition, over 92 percent of areas of forest expansion occurred within 100 m of established forest. These results suggest that the proximity of established forest facilitate forest recovery following human disturbance.
Phenology, Sexual Expression, and Reproductive Success of the Rare Neotropical Palm Geonoma epetiolata1
Authors: Martén Silvana , Quesada Mauricio 
Published: March 2006

ABSTRACTWe studied the phenology and reproductive biology of the stained glass palm Geonoma epetiolata in a premontane rain forest of Costa Rica. This understory species is endemic to Costa Rica and Panama. We followed 102 plants for two years and found that G. epetiolata is monoecious and protandrous. Flowering duration at the inflorescence level is three to six months for the male phase and two to three weeks for the female phase; this is one the most extended flowering periods reported for palms. Flowering in this palm is continuous throughout the year, both at the individual and population level. This long and continuous flowering pattern may represent an adaptation to increase the chances of reproduction in a environment of high and unpredictable rainfall. The species is self–compatible, but self–pollination is possible only when there is overlap of male and female inflorescences (38% of the cases). Only 28 percent of the stigmas of 1020 flowers received pollen grains and 20 percent developed pollen tubes in the styles. Of all the flowers produced by an inflorescence, 14 percent initiated fruit development but only 3 percent develop into mature fruits. Seventy–six percent of the initiated fruits were aborted.RESUMESEstudiamos la fenologia y la biología reproductiva de la palma Geonoma epetiolata en un bosque húmedo del pre‐montano en Costa Rica. Esta palma de sotobosque es endémica de Costa Rica y Panamá. Durante dos años observamos 102 plantas marcadas y encontramos que G. epetiolata es monoica y protándrica. La duración de floración a nivel de inflorescencia es de tres a seis meses para la fase masculina y de dos a tres semanas para la fase femenina, este es el período de floración más prolongado que se ha reportado para cualquier especie de palma. La floración de esta palma es continua a través del año, tanto a nivel individual como poblacional. Este partón de floración largo y continue parece representar una adaptación para aumentar las posibilidades de reproductión en un ambiente de precipitacion alta e impredecible. La especie es auto‐compatible pero la autopolinización solo es posible cuando existe traslape de flores femeninas y masculinas dentro de un mismo individuo (38% de los casos). Unicamente el 28 por ciento de los estigmas de 1020 flores analizadas recibieron granos de polen y 20 por ciento desarrollaron tubos polínicos en los estilos. De todas las flores producidas por una inflorescencia, en promedio 14 por ciento inician el desarrollo de frutos pero solo el 3 por ciento de las flores llega a producir frutos maduros. El 76 por ciento de los frutos iniciados se abortan.
Dietary Benefits of Twilight Foraging by the Insectivorous Bat Hipposideros speoris1
Authors: Pavey Chris R. , Burwell Chris J. , Grunwald Jan‐Eric , Marshall Chris J. , Neuweiler Gerhard 
Published: March 2006

ABSTRACTAlthough bats are nocturnal, many species emerge from roosts to forage during twilight, despite a presumed high risk of predation at this time. Here, we describe twilight foraging by a maternity colony of Schneider's leafnosed bat (Hipposideros speoris) in the dry zone of Sri Lanka and determine the dietary benefits of such behavior. Bats usually began foraging during dusk, sometimes before sunset, and also foraged during twilight in the morning. Mean use of available twilight by four radio‐tagged bats was 75 percent. Twilight foraging made up, on average, 47 percent of the total foraging time of these bats (range = 25–96%), although twilight consisted of only 12 percent of the available time between sunset and sunrise the next morning. Eight species of potential predators (7 birds and 1 mammal) were observed within a 1 km radius of the colony, of which 5 species are predicted to regularly capture bats. Bats took a wide diversity of prey (11 insect orders, including at least 27 families, and spiders) that ranged in wing length from 2.0 to 54.0 mm. Major orders in the diet were Coleoptera, Lepidoptera, and Diptera. Prey of secondary importance included Hemiptera, Hymenoptera, Isoptera, and Neuroptera. Bats captured large numbers of insects that were only available or had marked peaks in abundance during twilight. These groups included small, swarming insects (especially flies) that have peaks in flight activity at dusk and dawn, large diurnal species (especially dragonflies) that have crepuscular activity, and winged termites that emerge in swarms at dusk. Access to these insects was a clear benefit of twilight foraging.
Jaguar (Panthera onca) Food Habits in Atlantic Rain Forest of Southeastern Brazil1
Authors: Garla Ricardo C. , Setz Eleonore Z. F. , Gobbi Nivar 
Published: March 2006

ABSTRACTBetween January and December 1996, the food habits of a relict population of jaguars were studied in 220 km2 Linhares Forest Preserve, which comprises much of the remaining old‐growth Atlantic Forest of Espirito Santo, Brazil. Fecal analysis indicated opportunistic feeding on 24 prey species (N= 101 scats). Mammals represented 87 percent of the total items, followed by reptiles (9.8%) and birds (2.8%). Considering prey weight, 23.4 percent of the items weighed 1–3 kg, 40.5 percent were 3–10 kg, and 27.7 percent weighed more than 10 kg. Analysis of relative prey frequency and biomass indicated that the diet was concentrated in two prey types: long‐nosed armadillo and white‐lipped peccary. Literature data suggest that forest jaguars rely on the same mammal prey over their entire geographic range.RESUMESEntre janeiro e dezembro de 1996, os hábiros alimentares de uma populaçáo da onga pinrada foram estudados na Reserva Florestal de Linhares (220 km2), que cornpreende 25 porcento da floresra Atlintica primlria remanescente do Esrado do Espirito Santo, Brasil. A andise de fezes indicou o consumo de 24 esptcies de presas (N = 101 arnosrras). Mamiferos representaram 87 porcento do total de itens, seguidos por rtpteis (9.8%) e aves (2.8%). Considerando o peso das presas 23.4 porcento dos itens pesavam entre 1 e 3 kg, 40.5 porcenro de 3 a 10 kg, e 27.7 porcento acima de 10 kg. De acordo com a análise de freqütncia relariva de ocorrsncia e a estimariva de biomassa relativa, a dieta concentra‐se em dois itens: o tatu galinha e queixada. A onga pintada parece basear sua dieta nas mesmas esptcies de mamiferos ao longo de sua distribuig8o geogrlfica.
Comparative Genetic Structure between Tropical Colombian and North American Drosophila pseudoobscura Populations1
Authors: Alvarez Diana , Noor Mohamed A. F. , Ruiz‐Garcia Manuel 
Published: March 2006

ABSTRACTSince the discovery of Drosophila pseudoobscura in the tropical highlands of the Colombian Andes during the 1960s, this population has been studied by many evolutionary biologists because of its geographical isolation from the main North American range of this species. We used five highly variable microsatellite loci (DPSX001, DPS2001, DPS3001, DPS3002, and DPS4001) to analyze the genetic structure of three Colombian populations and the genetic relationships with four North American populations. We found that the average heterozygosity was consistent among the three tropical Colombian populations (H = 0.665–0.675), but they had less variability than their North American counterparts. Nonetheless, the genie diversity found in the Colombian populations was higher than that found previously using other genetic markers. The average genie heterogeneity estimate among the Colombian populations (Rjr = 0.042), although statistically significant, was substantially lower than that found among the North American populations (RsT = 0.088). We identified alleles in the Colombian populations not reported in North American populations, suggesting further divergence between the populations. We estimated that the populations on the two continents diverged ca 80,000 years ago, consistent with independent sequence analyses of these populations but contrary to some suggestions in the literature. Finally, we estimated an average effective population size of the Colombian populations to be on the order of 100,000.
Home Range of Dobsonia minor (Pteropodidae): A Solitary, Foliage–roosting Fruit Bat in Papua New Guinea
Authors: Bonaccorso Frank J. , Winkelmann John R. , Dumont Elizabeth R. , Thibault Katherlne 
Published: March 2006

ABSTRACTLesser bare–backed bats (Dobsonia minor [Pteropodidae]) are solitary and roost in foliage of understory and subcanopy trees in lowland rain forest. These 70–90 gram frugivorous bats forage in primary and secondary forest and in abandoned gardens. At the Kau Wildlife Area in Papua New Guinea, movements (N = 1041) of four males and four females fitted with radio transmitters were monitored for 1 to 18 months. Mean home range within 30–day sampling periods was 5.1 ha (N = 12). There were no significant differences in home ranges by sex or by dry–wet season. Females, however, had significandy larger mean core–use areas than males (1.43 ± 0.61 and 0.65 ±0.16 ha, respectively). There was moderate overlap in home range and core–use areas among some simultaneously tracked animals. The long axes of home ranges varied from 150 to 1150 m and the mean was significantly larger in females. Individuals commuted from day roosts to multiple feeding areas, sometimes resulting in disjunct core–use areas and home ranges. Fruits of native Fiats species and the exotic shrub Piper attuncum were staple food items. Piper aduncum grew as dense clusters within early successional habitats, and individual plants ripened 5–20 fruits per night throughout the year. Ficus spp. grew in primary and secondary forest and fruited asynchronously, but individual trees produced tens to thousands of ripe fruits over 7 to 10 days. Three adult female D. minor were tracked over multiple periods spanning 2.5–18 months. Although each female continued to visit a core–use area containing P. aduncum throughout the study, turnover of other core–use areas reflected the ephemeral locations of fruiting fig trees.
Organic Matter Dynamics on the Forest Floor of a Micronesian Mangrove Forest: An Investigation of Species Composition Shifts1
Authors: Gleason Sean M. , Ewel Katherine C. 
Published: March 2006

ABSTRACTSpecies composition shifts in mangrove forests may alter organic matter dynamics. The purpose of this study was to predict the effect of species replacements among mangrove trees on organic matter dynamics in a mangrove forest on the island of Kosrae, Federated States of Micronesia. We were particularly interested in elements of the carbon cycle that affect peat accumulation rates, organic matter exports to the estuary and coral reef systems, and soil microbiology. We compared organic matter production and decomposition rates among three mangrove species that commonly grow in similar hydrogeomorphic settings: Rhizophora apiculata BL, which is selectively harvested; Bruguiera gymnorrhiza, which may gradually replace Rhizophora; and Sonneratia alba, which is producing few mature fruits. Sonneratia had significantly higher rates of root production (estimated with ingrowth chambers) than Bruguiera or Rhizophora. Sonneratia foliage had significantly faster decomposition rates and significantly lower lignin:nitrogen ratios than Bruguiera foliage. Live root mass was positively correlated with ingrowth and soil carbon, although soil carbon and ingrowth were not significantly correlated with each other. Humic acid concentrations were significantly higher in Sonneratia rhizospheres than in either Bruguiera or Rhizophora rhizospheres and were positively correlated with root ingrowth. The species changes taking place on Kosrae are likely to result in lower rates of root production and foliage decomposition, and more refractory carbon pools in soil.
The Role of Cloud Combing and Shading by Isolated Trees in the Succession from Maquis to Rain Forest in New Caledonia1
Authors: Rigg L. S. , Enright N. J. , Perry G. L. W. , Miller B. P. 
Published: March 2006

ABSTRACTThis study examined the role of shading and cloud combing of moisture by scattered trees of the emergent conifer Araucaria laubenfelsii (Corbass.) in montane shrubland‐maquis at Mont Do, New Caledonia, in facilitating the succession from shrubland to rain forest. Water collection experiments showed that these trees combed significant amounts of water from low clouds on days when no rainfall was recorded and deposited this moisture on the ground beneath the tree canopy. Analysis of photosystem II function in A. laubenfelsii and five other plant species using fluorometry revealed much lower photosystem stress in plants beneath scattered A. laubenfelsii than for individuals exposed to full sunlight in the open maquis. Transition matrix analyses of vegetation change based on “the most likely recruit to succeed” indicated that the transition from maquis to forest was markedly faster when emergent trees of A. laubenfelsii acted as nuclei for forest species invasion of die maquis. On the basis of these lines of evidence, it is argued that increased moisture and shading supplied to the area directly below the crown of isolated A. laubenfelsii trees in the maquis facilitates the establishment of both conifer seedlings and other rain forest tree and shrub species. In the absence of fire, rain forest can reestablish through spread in two ways: first, by expansion from remnant patches, and second, from coalescence of small rain forest patches formed around individual trees of A. laubenfelsii.
High Temperatures and Net CO2 Uptake, Growth, and Stem Damage for the Hemiepiphytic Cactus Hylocereus undatus1
Authors: Nobel Park S. , De la Barrera Erick 
Published: March 2006

ABSTRACT Hylocereus undatus, which is native to tropical forests experiencing moderate temperatures, would not be expected to tolerate the extremely high temperatures that can be tolerated by cacti native to deserts. Nevertheless, total daily net CO2 uptake by this hemiepiphytic cactus, which is widely cultivated for its fruits, was optimal at day/night air temperatures of 30/20°C, temperatures that are higher than those optimal for daily net CO2 uptake by cacti native to arid and semiarid areas. Exposure to 35/25°C for 30 weeks led to lower net CO2 uptake than at 10 weeks; exposure to 40/30°C led to considerable necrosis visible on the stems at 6 weeks and nearly complete browning of the stems by 19 weeks. Dry mass gain over 31 weeks was greatest for plants at 30/20°C, with root growth being especially noteworthy and root dry mass gain representing an increasing percentage of plant dry mass gain as day/night air temperatures were increased. Viability of chlorenchyma cells, assayed by the uptake of the vital stain neutral red into the central vacuoles, was decreased 50 percent by a one‐hour treatment at 55°C compared with an average of 64°C for 18 species of cacti native to deserts. The lower high‐temperature tolerance for H. undatus reflected its low high‐temperature acclimation of only 1.4°C as growth temperatures were raised by 10°C compared with an average acclimation of 5.3°C for the other 18 species of cacti. Thus, this tropical hemiepiphytic cactus is not adapted to day/night air temperatures above ca 40/30°C, although its net CO2 uptake is optimal at the relatively high day/night air temperatures of 30/20°C.
Disperser‐ vs. Establishment‐Limited Distribution of a Riparian Fig Tree (Ficus insipida) in a Costa Rican Tropical Rain Forest1
Authors: Banack Sandra Anne , Horn Michael H. , Gawlicka Anna 
Published: March 2006

ABSTRACTStudies were conducted at the La Selva Biological Station in Costa Rica and in a greenhouse in California to determine the factors accounting for the nonrandom distribution of the riparian fig tree Ficus insipida Willd. along streams in the La Selva Biological Reserve and adjacent deforested lands. We also evaluated the potential seed dispersers of this tree relative to the role of the fruit‐eating fish Brycon guatemalensis that previously was proposed to be an important disperser of F. insipida seeds in this system. At La Selva, we recorded the fig‐foraging activities of vertebrates at fruiting F. insipida trees, surveyed for the presence or absence of F. insipida along streams of different sizes, and determined the fate of fig seedlings transplanted in different riparian habitats. In the greenhouse, we measured seed germination and seedling survival and growth under different light and soil pH conditions mimicking natural conditions. The findings provided evidence that (1) the tree occurs along the larger streams running through forest habitat and only along smaller streams with relatively high light availability; (2) bats (Artibeus spp.) and fish are the major dispersers of F. insipida seeds; (3) the seedlings are subject to mortality not only from low light conditions but also from treefalls, frequent flooding, and bank erosion; and (4) high light levels and near neutral soil pH result in relatively better seed germination, faster growth, and higher survival rates of seedlings. Overall, our results suggest that this fig tree is dispersed mainly by bats and fish and is more establishment‐limited than disperser‐limited in its local distribution in the La Selva rain forest habitat.
Ornithophilous and Chiropterophilous Pollination in Musa itinerans (Musaceae), a Pioneer Species in Tropical Rain Forests of Yunnan, Southwestern China1
Authors: Liu Ai‐Zhong , Li De‐Zhu , Wang Hong , Kress W. John 
Published: March 2006

ABSTRACTThe role of bats and sunbirds in the pollination ecology of Musa itinerans Cheesman (Musaceae) was studied in the tropical seasonal rain forests of Xishuangbanna, southern Yunnan, China. It was found that both long–tongued fruit bats (Macroglossus sobrinus) and sunbirds (Arachnothera longirostris) were effective pollinators of M. itinerans. Nectar production had two peaks, one during the day and one during night (0800–1200 h and 2000–2400 h), which allowed the two different foragers to visit at specific times. The visitation patterns of the two foragers coincided with both flowering time and nectar production. By measuring the differences in fruit weight and seed production among different bagging experiments, we found that birds and bats were equally effective as pollinators of this species.
Primary Seed Dispersal by Red Howler Monkeys and the Effect of Defecation Patterns on the Fate of Dispersed Seeds1
Authors: Andresen Ellen 
Published: March 2006

ABSTRACTThe effectiveness of a seed disperser depends on the quantity and quality of dispersal. The quality of dispersal depends in large part on factors that affect the post–dispersal fate of seeds, and yet this aspect of dispersal quality is rarely assessed. In the particular case of seed dispersal through endozoochory, the defecation pattern produced has the potential of affecting the fate of dispersed seeds and consequently, dispersal quality and effectiveness. In this study, I assessed the effects of dung presence and dung/seed densities on seed predation by rodents and secondary dispersal by dung beetles. In particular, I compared seed fates in clumped defecation patterns, as those produced by howler monkeys, with seed fates in scattered defecation patterns, as those produced by other frugivores. I also determined the prevalence of red howler monkeys(Alouatta seniculus)as seed dispersers at the plant community level in Central Amazonia by determining the number of species they dispersed in a 25–month period. I found that dung presence and amount affected rodent and dung beetle behavior. Seed predation rates were higher when dung was present, and when it was in higher densities. The same number of seeds was buried by dung beedes, in dumped versus scattered defecation patterns, but more seeds were buried when they were inside large dung–piles versus small piles. Seed density had no effect on rodent or dung beetle behavior. Results indicate that caution should be taken when categorizing an animal as a high or low quality seed disperser before carefully examining the factors that affect the fate of dispersed seeds. Red howler monkeys dispersed the seeds of 137 species during the study period, which is the highest yet reported number for anAlouattaspecies, and should thus be considered highly prevalent seed dispersers at the plant community level in Central Amazonian terra firme rain forests.