68 research outputs found

    Effect of Resting Patterns of Tamarins (Saguinus fuscicollis and Saguinus mystax) on the Spatial Distribution of Seeds and Seedling Recruitment

    Get PDF
    The spatial distributions of dispersed seeds have important evolutionary consequences for plants. Repeated defecations in sites frequently used by seed dispersers can result in high seed concentrations. We observed the resting behavior of a mixed-species group of tamarins in Peru and recorded the occurrence of seed dispersal (over 8 mo) and seed fate (over 11–22 mo) to determine whether the location and use of resting sites influenced the spatial distribution of dispersed seeds and seedlings. The tamarins rested mostly on trees (Saguinus fuscicollis: 60.6%, S. mystax: 89.2%) and dead trunks (S. fuscicollis: 24.4%) and used 61% of their resting sites repeatedly. During both the dry and wet seasons, tamarins dispersed significantly more seeds within resting areas (0.00662 and 0.00424 seeds/m2, respectively) than outside them (0.00141 and 0.00181 seeds/m2). Seed survival and seedling recruitment did not differ significantly between resting and other areas, resulting in a higher seedling concentration around the resting sites. Seed density did not increase with the duration or the frequency of use of the resting sites but did increase when we pooled the seasonal resting sites together in 50 m × 50 m quadrats, ultimately causing a clumped distribution of dispersed seeds. The use of resting sites in secondary forest, particularly during the dry season, allows the creation of seedling recruitment centers for species coming from the primary forest. Our findings show that tamarin resting behavior affects the spatial distribution of dispersed seeds and seedlings, and their resting sites play an important role in plant diversity maintenance and facilitate forest regeneration in degraded areas

    DNA Fingerprinting Validates Seed Dispersal Curves from Observational Studies in the Neotropical Legume Parkia

    Get PDF
    Background: Determining the distances over which seeds are dispersed is a crucial component for examining spatial patterns of seed dispersal and their consequences for plant reproductive success and population structure. However, following the fate of individual seeds after removal from the source tree till deposition at a distant place is generally extremely difficult. Here we provide a comparison of observationally and genetically determined seed dispersal distances and dispersal curves in a Neotropical animal-plant system. Methodology/Principal Findings: In a field study on the dispersal of seeds of three Parkia (Fabaceae) species by two Neotropical primate species, Saguinus fuscicollis and Saguinus mystax, in Peruvian Amazonia, we observationally determined dispersal distances. These dispersal distances were then validated through DNA fingerprinting, by matching DNA from the maternally derived seed coat to DNA from potential source trees. We found that dispersal distances are strongly rightskewed, and that distributions obtained through observational and genetic methods and fitted distributions do not differ significantly from each other. Conclusions/Significance: Our study showed that seed dispersal distances can be reliably estimated through observational methods when a strict criterion for inclusion of seeds is observed. Furthermore, dispersal distances produced by the two primate species indicated that these primates fulfil one of the criteria for efficient seed dispersers. Finally, our stud

    Influences on gum feeding in primates

    Get PDF
    This chapter reviews the factors that may affect patterns of gum feeding by primates. These are then examined for mixed-species troops of saddleback (S. fuscicollis) and mustached (S. mystax) tamarins. An important distinction is made between gums produced by tree trunks and branches as a result of damage and those produced by seed pods as part of a dispersal strategy as these may be expected to differ in their biochemistry. Feeding on fruit and Parkia seed pod exudates was more prevalent in the morning whereas other exudates were eaten in the afternoon. This itinerary may represent a deliberate strategy to retain trunk gums in the gut overnight, thus maximising the potential for microbial fermentation of their β-linked oligosaccharides. Both types of exudates were eaten more in the dry than the wet season. Consumption was linked to seasonal changes in resource availability and not the tamarins’ reproductive status pro-viding no support for the suggestion that gums are eaten as a pri-mary calcium source in the later stages of gestation and lactation. The role of availability in determining patterns of consumption is further supported by the finding that dietary overlap for the trunk gums eaten was greater between species within mixed-species troops within years than it was within species between years. These data and those for pygmy marmosets (Cebuella pygmaea) suggest that patterns of primate gummivory may reflect the interaction of prefer-ence and availability for both those able to stimulate gum production and those not

    Factors influencing terrestriality in primates of the Americas and Madagascar

    Get PDF
    Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (bodymass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

    Seasonal variation and an “outbreak” of frog predation by tamarins

    Get PDF
    We report temporal variation and an “outbreak” of frog predation by moustached tamarins, Saguinus mystax, in north-eastern Peruvian Amazonia. Frog predation rates were generally very low, but strongly increased in October 2015. Other high rates, identified by outlier analyses, were also observed in September–November of other years. Over all study years, predation rates in this 3-month period were significantly higher than those in the remainder of the year, suggesting a seasonal pattern of frog predation by tamarins. Reduced fruit availability or increased frog abundance or a combination of both may be responsible for both the seasonal pattern and the specific “outbreak” of frog predation

    Factors influencing terrestriality in primates of the Americas and Madagascar

    Get PDF
    Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (body mass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

    ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

    Get PDF
    Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

    Larval Competition In Weevils Revena Rubiginosa (coleoptera: Curculionidae) Preying On Seeds Of The Palm Syagrus Romanzoffiana (arecaceae)

    No full text
    Inter- and intraspecific local resource competition may lead to the selection of specific adaptive individual characteristics to overcome interference competition. A highly selective scenario is predictable for interference competition among seed preying weevil larvae that live in and feed upon a single host seed. This scenario is found in Syagrus romanzoffiana palm seeds which are predated by Revena rubiginosa (Curculionidae) larvae. Although multiple infestation of one seed by weevil larvae can occur, invariably only one individual survives and develops in each host seed. A strong competition between the first instar larvae in a restricted window of host fruit development stages leads to physical interactions of conspecifics by ovicide or direct fighting using falcate mandibles. The occurrence of this type of mandible is synchronized with fruit development and restricted to instars with probable competition, as infestation occurs only while the endocarp is soft. Only after lignification of the endocarp the larva changes into the next instar. Mandibles of subsequent instars differ markedly from those of the first instar. The new mandibles can scrape the solid endosperm but are unable to perforate and kill conspecifics. These findings give strong evidence for the selective pressure of intraspecific competition, where special behaviour, mandible morphology and synchronization of its changes with the seed development contribute to individual benefit that involves the killing of conspecifics, since one host seed can only maintain a single larva throughout its complete development. © Springer-Verlag 2005.926265268Bondar, G., Notas entomológicas de Baía XIII (1943) Rev Entomol (Rio de Janeiro), 14, pp. 337-388Guedes, R.N., Smith, R.H., Guedes, N.M.P., Host suitability, respiration rate and the outcome of larval competition in strains of the cowpea weevil, Callosobruchus maculatus (2003) Phys Entomol, 28, pp. 298-305Guix, J.C., Ruiz, X., Weevil larvae dispersal by guans in Southeastern Brazil (1997) Biotrpica, 29 (4), pp. 522-525Ishihara, M., Shimada, M., Female-biased sex ratio in a wild bruchid seed-predator, Kytorhinus sharpianus. I. Larval competition and other factors (1993) Ecol Entomol, 18, pp. 54-60Janzen, D.H., Intra- and interhabitat variations in Guazuma ulmifolia (Sterculiaceae) seed predation by Amblycerus cistelinus (Bruchidae) in Costa Rica (1975) Ecology, 56, pp. 1009-1013Johnson, C.D., Ecology of Neltumius texanus (Coleoptera Bruchidae) in the seeds of Candalia (Rhamnaceae) (1978) J Kans Entomol Soc, 51, pp. 432-440Kirkpatrick, R.L., Wilbur, D.A., The development and habits of the granary weevil Sitophilus granarius within the kernel of wheat (1965) J Econ Entomol, 58, pp. 979-985May, B.M., An introduction to the immature stages of Australian Curculionoidea (1994) Australian Weevils, 2, pp. 367-755. , Zimmerman EC (ed) CSIRO Publishing, MelbourneNénon, J.-P., Boivin, G., Le Lannic, J., Van Baaren, J., Functional morphology of the mymariform and sacciform larvae of the egg parasitoid Anaphes victus Huber (Hymenoptera: Mymaridae) (1995) Can Zool, 73, pp. 996-1000Sanz, M.J., Gurrea, P., Life-cycles and competition-avoiding strategies of seed-eating weevil species on broom species (Coleoptera: Curculionidae/Leguminosae: Genisteae) (2000) Entomol Gen, 24, pp. 237-254Salt, G., Competition among insect parasitoids (1961) Symp Soc Exp Biol, 15, pp. 96-119Scherf, H., Die Entwicklungsstadien der mitteleuropäischen Curculioniden (Morphologie, Bionomie, Ökologie) (1964) Abh Senckenb Naturf Ges, 506, pp. 1-335Stehr, F.W., (1991) Immature Insects, 2. , Kendal/Hunt, Dubuque, IowaThanthianga, C., Mitchell, R., Vibrations mediate prudent resource exploitation by competing larvae of the bruchid bean weevil Callosobruchus maculatus (1987) Entomol Exp Appl, 44, pp. 15-21Van Alphen, J.J.M., Visser, M.E., Superparasitism as an adaptive strategy for insect parasitoids (1990) Annu Rev Entomol, 35, pp. 59-79Van Baaren, J., Boivin, G., Nénon, J.P., Intraspecific hyperparasitism in a primary Hymenopteran parasitoid (1995) Behav Ecol Sociobiol, 36, pp. 237-242Van Baaren, J., Boivin, G., Le Lannic, J., Nénon, J.P., The male and female first instar larvae of Anaphes victus and A. listronoti (Hymenoptera, Myrmaridae) (1997) Zoomorphology, 117, pp. 89-197Van Baaren, J., Landry, B.L., Boivin, G., Sex allocation and larval competition in a superparasitizing solitary egg parasitoid: Competing strategies for an optimal sex ratio (1999) Funct Ecol, 13, pp. 66-71Wang, R., Kok, L.T., Life history of Megacerus discoidits (Coleoptera: Bruchidae), a seedfeeder of hedge bindweed, in Southwestern Virginia (1986) Annu Entomol Soc Am, 79, pp. 359-36

    Larval competition in weevils Revena rubiginosa (Coleoptera : Curculionidae) preying on seeds of the palm Syagrus romanzoffiana (Arecaceae)

    No full text
    Inter- and intraspecific local resource competition may lead to the selection of specific adaptive individual characteristics to overcome interference competition. A highly selective scenario is predictable for interference competition among seed preying weevil larvae that live in and feed upon a single host seed. This scenario is found in Syagrus romanzoffiana palm seeds which are predated by Revena rubiginosa (Curculionidae) larvae. Although multiple infestation of one seed by weevil larvae can occur, invariably only one individual survives and develops in each host seed. A strong competition between the first instar larvae in a restricted window of host fruit development stages leads to physical interactions of conspecifics by ovicide or direct fighting using falcate mandibles. The occurrence of this type of mandible is synchronized with fruit development and restricted to instars with probable competition, as infestation occurs only while the endocarp is soft. Only after lignification of the endocarp the larva changes into the next instar. Mandibles of subsequent instars differ markedly from those of the first instar. The new mandibles can scrape the solid endosperm but are unable to perforate and kill conspecifics. These findings give strong evidence for the selective pressure of intraspecific competition, where special behaviour, mandible morphology and synchronization of its changes with the seed development contribute to individual benefit that involves the killing of conspecifics, since one host seed can only maintain a single larva throughout its complete development.92626526
    • …
    corecore