6 research outputs found
Fitness Impacts of Tapeworm Parasitism on Wild Gelada Monkeys at Guassa, Ethiopia
No full textParasitism is expected to impact host morbidity or mortality, although the fitness costs of parasitism have rarely been quantified for wildlife hosts. Tapeworms in the genus Taenia exploit a variety of vertebrates, including livestock, humans, and geladas (Theropithecus gelada), monkeys endemic to the alpine grasslands of Ethiopia. Despite Taenia's adverse societal and economic impacts, we know little about the prevalence of disease associated with Taenia infection in wildlife or the impacts of this disease on host health, mortality and reproduction. We monitored geladas at Guassa, Ethiopia over a continuous 61/2 year period for external evidence (cysts or coenuri) of Taenia-associated disease (coenurosis) and evaluated the impact of coenurosis on host survival and reproduction. We also identified (through genetic and histological analyses) the tapeworms causing coenurosis in wild geladas at Guassa as Taenia serialis. Nearly 1/3 of adult geladas at Guassa possessed 1 coenurus at some point in the study. Coenurosis adversely impacted gelada survival and reproduction at Guassa and this impact spanned two generations: adults with coenuri suffered higher mortality than members of their sex without coenuri and offspring of females with coenuri also suffered higher mortality. Coenurosis also negatively affected adult reproduction, lengthening interbirth intervals and reducing the likelihood that males successfully assumed reproductive control over units of females. Our study provides the first empirical evidence that coenurosis increases mortality and reduces fertility in wild nonhuman primate hosts. Our research highlights the value of longitudinal monitoring of individually recognized animals in natural populations for advancing knowledge of parasite-host evolutionary dynamics and offering clues to the etiology and control of infectious disease. Am. J. Primatol. 77:579-594, 2015. (c) 2015 Wiley Periodicals, Inc
) and their implications for understanding human and nonhuman primate birth evolution
No full textObjectives The birth process has been studied extensively in many human societies, yet little is known about this essential life history event in other primates. Here, we provide the most detailed account of behaviors surrounding birth for any wild nonhuman primate to date. Materials and Methods Over a recent similar to 10-year period, we directly observed 15 diurnal births (13 live births and 2 stillbirths) among geladas (Theropithecus gelada) at Guassa, Ethiopia. During each birth, we recorded the occurrence (or absence) of 16 periparturitional events, chosen for their potential to provide comparative evolutionary insights into the factors that shaped birth behaviors in humans and other primates. Results We found that several events (e.g., adopting standing crouched positions, delivering infants headfirst) occurred during all births, while other events (e.g., aiding the infant from the birth canal, licking infants following delivery, placentophagy) occurred during, or immediately after, most births. Moreover, multiparas (n=9) were more likely than primiparas (n=6) to (a) give birth later in the day, (b) isolate themselves from nearby conspecifics while giving birth, (c) aid the infant from the birth canal, and (d) consume the placenta. Discussion Our results suggest that prior maternal experience may contribute to greater competence or efficiency during the birth process. Moreover, face presentations (in which infants are born with their neck extended and their face appearing first, facing the mother) appear to be the norm for geladas. Lastly, malpresentations (in which infants are born in the occiput anterior position more typical of human infants) may be associated with increased mortality in this species. We compare the birth process in geladas to those in other primates (including humans) and discuss several key implications of our study for advancing understanding of obstetrics and the mechanism of labor in humans and nonhuman primates
Understanding nitrogen transfer dynamics in a small agricultural catchment: Comparison of a distributed (TNT2) and a semi distributed (SWAT) modeling approaches
No full textThe coupling of an hydrological and a crop model is an efficient approach to study the impact of the interactions between agricultural practices and catchment physical characteristics on stream water quality. We analyzed the consequences of using different modeling approaches of the processes controlling the nitrogen (N) dynamics in a small agricultural catchment monitored for 15 years. Two agro-hydrological models were applied: the fully distributed model TNT2 and the semi-distributed SWAT model. Using the same input dataset, the calibration process aimed at reproducing the same annual water and N balance in both models, to compare the spatial and temporal variability of the main N processes. The models simulated different seasonal cycles for soil N. The main processes involved were N mineralization and denitrification. TNT2 simulated marked seasonal variations with a net increase of mineralization in autumn, after a transient immobilization phase due to the burying of the straw with low C:N ratio. SWAT predicted a steady humus mineralization with an increase when straws are buried and a decrease afterwards. Denitrification was mainly occuring in autumn in TNT2 because of the dynamics of N availability in soil and of the climatic and hydrological conditions. SWAT predicts denitrification in winter, when mineral N is available in soil layers. The spatial distribution of these two processes was different as well: less denitrification in bottom land and close to ditches in TNT2, as a result of N transfer dynamics. Both models simulate correctly global trend and inter-annual variability of N losses in small agricultural catchment when a sufficient amount data is available for calibration. However, N processes and their spatial interactions are simulated very differently, in particular soil mineralization and denitrification. The use of such tools for prediction must be considered with care, unless a proper calibration and validation of the different N processes is carried out
Death among geladas (Theropithecus gelada): a broader perspective on mummified infants and primate thanatology
No full textThe ecology of insect pests and fungal pathogens of drought stressed eucalypt plantations in southern Queensland
No full textThe eucalypt plantation industry is rapidly expanding to supply an increasing demand for wood both in Australia and other parts of the world. Despite rapid industry development, most eucalypt plantations are restricted to four coastal areas. These include the southwest corner of Western Australia, eastern New South Wales, the ‘Green Triangle’ (western Victoria and eastern South Australia) and Tasmania. Eucalypt plantations are traditionally grown in these areas because they have favourable climatic conditions which allow high productivity. Eucalyptus globulus is a fast growing eucalypt species and is currently the most widely planted species in Australia (55.3% of all eucalypt plantations).
More recently, plantations have been grown in other parts of Australia which are less suited to E. globulus. The eucalypt plantation industry in southern Queensland is in its infancy and has received less attention from researchers compared with Australia’s main plantation centres. Species selection has been a major focus and E. dunnii is quickly emerging as one of the most widely planted species. Most of the biological research of Eucalyptus dunnii has been carried out in plantations in Brazil and South Africa where the species is an important source of pulp for paper production. The suitability of E. dunnii in Australian plantations is still being explored and little is currently known about its susceptibility to pests, pathogens or climatic extremes.
This is the first comprehensive study of E. dunnii plantations in southern Queensland. Unlike most research in plantations which examines the impacts of insect pests and fungal pathogens as separate areas of research, this study focuses on both groups simultaneously. Understanding the ecology of pests and pathogens is an important aspect of plantation management and is essential to the development of the plantation industry in southern Queensland.
A large diversity of pests and pathogens were identified from E. dunnii plantations during the study. Impacts by insects were generally more severe than pathogens although most pests and pathogens were found to cause low levels of damage. Severe impacts were caused by chrysomelid beetles such as Paropsisterna cloelia which was the most destructive chrysomelid species. Differences in the abundances of chrysomelid damage were observed in different aged plantations and between plantations occurring in different regions of southern Queensland.
Several genera of pathogenic fungi were identified and the most abundant species belonged to the genera Mycosphaerella and Teratosphaeria. The most damaging of these species was Mycosphaerella heimii, which was previously unknown in Australia. Canker pathogens such as Holocryphia eucalypti, Neofusicoccum ribis and Cytospora eucalypticola were also common in younger plantations (aged 1-2 years). H. eucalypti was identified as the causal pathogen of ‘sudden death syndrome’ and was the only pathogen observed to be capable of killing its host.
Three new species of foliar fungal pathogens were identified belonging to the genus, Teratosphaeria. These species were associated with drought stressed hosts and are likely to represent a small fraction of a potentially larger assemblage of undescribed species awaiting discovery in southern Queensland.
It was expected that the subtropical climate in southern Queensland would be conducive to a large diversity of pests and pathogens. Despite these expectations, widespread drought in eastern Australia (2003-2007) created atypical conditions within the region which had adverse effects on many species. Drought effects may have benefited some insects, such as those which feed on new foliage produced by stressed trees; however, most foliar pathogens appeared to be adversely affected. Some canker
pathogens appeared to exploit stressed trees and thirteen weak opportunistic pathogens were identified from stem cankers and necrotic stem tissues. Some saprophytic fungi may have benefited from greater availability of dead tissue due to a higher incidence of wilting and premature leaf loss.
Although drought effects may have overshadowed the effects of pests and pathogens, the resulting conditions provided valuable insight into the ecology of drought stress in plantations. A conceptual model called the ‘Recovery-Decline Seesaw’ has been developed to illustrate the complex interactions of drought stressed trees and their associated pests and pathogens. The study also contributes valuable information which aims to facilitate development of the southern Queensland plantation industry
Ocio experiencial: antecedentes y características
No full textAt the turn of the century, the article analyzes the changes suffered by the conceptual understanding of leisure, whose meaning is nowadays defined as an experience. The writers review the main streams and authors that drove the mentioned evolution and also pay attention to the people that currently experience leisure in this way. After a first chapter committed to literature review, a sample of leisure practitioners devoted to any leisure practice at least during the last three years is studied. The sample is asked about its experiences and perceptions. The article is written within the framework of an emic perspective and the methodology used is based on the grounded theory principles. The article focus its attention into five main characteristics of leisure experience: persona centered, emotion, satisfaction, involvement and procesual nature of leisure experience. The aim of the work is to draw up a general picture about the meaning and practice of the leisure experience in the 21st Century.El artículo trata del cambio conceptual desde el que percibimos el ocio en el siglo XXI, el ocio experiencial. Para ello nos acercamos a los autores y corrientes que gestionaron este cambio y también a las personas que viven el ocio de ese modo. Tras un primer apartado dedicado a la revisión de la literatura sobre la experiencia de ocio, se estudia a un grupo de personas implicadas durante al menos tres años en alguna práctica de ocio, a las que se les ha preguntado sobre sus percepciones y experiencias. Se parte de una perspectiva émica, a partir de una metodología con base en la grounded theory. Este trabajo se limita al análisis de cinco características básicas de la experiencia de ocio: Persona, emoción, satisfacción, integración y proceso. El trabajo persigue perfilar un panorama general sobre el significado de la supervivencia de ocio, que difícilmente se explicaría sin el ocio experiencial
