A Method for Estimating the Current and Future Carbon Content of Standing Biomass Applied to Gishwati Forest Reserve, Rwanda

The carbon content of standing tree biomass was determined in the Gishwati Forest Reserve in north-western Rwanda and growth potential of the forest was estimated using a straightforward, generalisable model of natural forest regeneration. A survey was conducted on 2289 trees in plots throughout the reserve. Wood density data were obtained from literature and tree biomass was estimated using a recent pan-tropical allometric equation. A survey on United Nations Framework Convention on Climate Change (UNFCCC) Clean Development Mechanism (CDM) projects showed that current methods of growth rate projection for mixed, non-plantation forests might significantly overestimate the amount of carbon sequestered. The current study identified an alternative potential method for the estimation of sequestration rates that did not depend upon compiling single-species growth rates and reduced the risk that error would lead to significant over- or underestimation of total biomass sequestration potential. This method used remote-sensing data to estimate total biomass potential in a mature forest based upon local samples and assumes a standard growth trajectory based upon literature values. The benefits in terms of accuracy and ease of model construction are likely to be high. It was found that tree biomass in Gishwati forest contained 53.9 ± 10 CO2 equivalent(e) ha-1 and was expected to sequester an average of 1.01 (0.80–1.38) Mg CO2e ha-1 per annum over the next 30 years

Uncovering ‘Hidden’ Signals:Previously Presumed Visual Signals Likely Generate Air Particle Movement

Wolf spiders within the genus Schizocosa have become a model system for exploring the form and function of multimodal communication. In terms of male signaling, much past research has focused on the role and importance of dynamic and static visual and substrate-borne vibratory communication. Studies on S. retrorsa, however, have found that female-male pairs were able to successfully mate in the absence of both visual and vibratory stimuli, suggesting a reduced or non-existent role of these signaling modalities in this species. Given these prior findings, it has been suggested that S. retrorsa males may utilize an additional signaling modality during courtship-air particle movement, often referred to as near-field sound-which they likely produce with rapid leg waving and receive using thin filiform sensory hairs called trichobothria. In this study, we tested the role of air-particle movement in mating success by conducting two independent sets of mating trials with randomly paired S. retrorsa females and males in the dark and on granite (i.e., without visual or vibratory signals) in two different signaling environments-(i) without ( No Noise ) and (ii) with ( Noise ) introduced air-particle movement intended to disrupt signaling in that modality. We also ran foraging trials in No Noise/Noise environments to explore the impact of our treatments on overall behavior. Across both mating experiments, our treatments significantly impacted mating success, with more mating in the No Noise signaling environments compared to the Noise environments. The rate of leg waving-a previously assumed visual dynamic movement that has also been shown to be able to produce air particle displacement-was higher in the No Noise than Noise environments. Across both treatments, males with higher rates of leg waving had higher mating success. In contrast to mating trials results, foraging success was not influenced by Noise. Our results indicate that artificially induced air particle movement disrupts successful mating and alters male courtship signaling but does not interfere with a female\u27s ability to receive and assess the rate of male leg waving

Order Effects of Ballot Position without Information-Induced Confirmatory Bias

Candidate list positions have been shown to influence decision making when voters have limited candidate information (e.g. Miller and Krosnick, 1998; Brockington, 2003). Here, a primacy advantage is observed due to a greater number of positive arguments generated for early list candidates (Krosnick, 1991). The present study examined list position effects when an absence of information precludes such a confirmatory bias heuristic. We report the first large scale low-information experimental election where candidate position is fully counterbalanced. Seven hundred and twenty participants voted in a mock election where the position of 6 fictitious and meaningless parties was counterbalanced across the electorate. Analysis by position revealed that significantly fewer votes were allocated to the terminal parties (Experiment 1). In addition, Experiment 1 reported preliminary evidence of an alphabetical bias (consistent with Bagley, 1966). However, this positional bias was not present in a methodological replication using six genuine UK political parties (Experiment 2). This suggests that in situations of pure guessing, the heuristic shifts from the primacy benefiting confirmatory bias to an alternative heuristic that prejudices the first and last parties. These findings suggest that whilst the UK general electoral process may be largely immune to positional prejudice, English local elections (in which there can be multiple candidates from the same party) and multiple preference ranking systems (Scottish Local Government and London Mayoral Elections) could be susceptible to both positional and alphabetical biases

Increased signal complexity is associated with increased mating success

The evolution of complex signals has often been explored by testing multiple functional hypotheses regarding how independent signal components provide selective benefits to offset the costs of their production. In the present study, we take a different approach by exploring the function of complexity per se. We test the hypothesis that increased vibratory signal complexity—based on both proportional and temporal patterning—provides selective benefits to courting male Schizocosa stridulans wolf spiders. In support of this hypothesis, all of our quantified metrics of vibratory signal complexity predicted the mating success of male S. stridulans. The rate of visual signalling, which is mechanistically tied to vibratory signal production, was also associated with mating success. We additionally found evidence that males can dynamically adjust the complexity of their vibratory signalling. Together, our results suggest that complexity per se may be a target of female choice

Increased signal complexity is associated with increased mating success

The evolution of complex signals has often been explored by testing multiple functional hypotheses regarding how independent signal components provide selective benefits to offset the costs of their production. In the present study, we take a different approach by exploring the function of complexity per se. We test the hypothesis that increased vibratory signal complexity—based on both proportional and temporal patterning—provides selective benefits to courting male Schizocosa stridulans wolf spiders. In support of this hypothesis, all of our quantified metrics of vibratory signal complexity predicted the mating success of male S. stridulans. The rate of visual signalling, which is mechanistically tied to vibratory signal production, was also associated with mating success. We additionally found evidence that males can dynamically adjust the complexity of their vibratory signalling. Together, our results suggest that complexity per se may be a target of female choice

Research and Analysis of Fisheries in Illinois

Reports on progress and results for the following project objectives: sport fish population and sport fishing metrics; enhanced field sampling of sport fish populations; determination of factors affecting fishing quality; coordination with ongoing fisheries research projects; support for and enhance of web interface; fishes of Champaign County; recovery of urban stream sport fisheries.Illinois Department of Natural Resources, Division of Fisheries, Federal Aid Project F-69-R Segment 28unpublishednot peer reviewedOpe

The ecology and epidemiology of malaria parasitism in wild chimpanzee reservoirs

This work was supported by grants from the National Institutes of Health R01AI091595, R01AI120810, R01AI050529, and P30AI045008 (B.H.H.); R01HL139337 (M.T.D.), the National Geographic Society (E.J.S.), the International Primatological Society (E.J.S.), and the American Society of Primatologists (E.J.S.), as well as fellowships from Harvard University (E.J.S.) and the National Science Foundation (E.J.S.).Chimpanzees (Pan troglodytes) harbor rich assemblages of malaria parasites, including three species closely related to P. falciparum (sub-genus Laverania), the most malignant human malaria parasite. Here, we characterize the ecology and epidemiology of malaria infection in wild chimpanzee reservoirs. We used molecular assays to screen chimpanzee fecal samples, collected longitudinally and cross-sectionally from wild populations, for malaria parasite mitochondrial DNA. We found that chimpanzee malaria parasitism has an early age of onset and varies seasonally in prevalence. A subset of samples revealed Hepatocystis mitochondrial DNA, with phylogenetic analyses suggesting that Hepatocystis appears to cross species barriers more easily than Laverania. Longitudinal and cross-sectional sampling independently support the hypothesis that mean ambient temperature drives spatiotemporal variation in chimpanzee Laverania infection. Infection probability peaked at ~24.5 °C, consistent with the empirical transmission optimum of P. falciparum in humans. Forest cover was also positively correlated with spatial variation in Laverania prevalence, consistent with the observation that forest-dwelling Anophelines are the primary vectors. Extrapolating these relationships across equatorial Africa, we map spatiotemporal variation in the suitability of chimpanzee habitat for Laverania transmission, offering a hypothetical baseline indicator of human exposure risk.Publisher PDFPeer reviewe

The ecology and epidemiology of malaria parasitism in wild chimpanzee reservoirs

Chimpanzees (Pan troglodytes) harbor rich assemblages of malaria parasites, including three species closely related to P. falciparum (sub-genus Laverania), the most malignant human malaria parasite. Here, we characterize the ecology and epidemiology of malaria infection in wild chimpanzee reservoirs. We used molecular assays to screen chimpanzee fecal samples, collected longitudinally and cross-sectionally from wild populations, for malaria parasite mitochondrial DNA. We found that chimpanzee malaria parasitism has an early age of onset and varies seasonally in prevalence. A subset of samples revealed Hepatocystis mitochondrial DNA, with phylogenetic analyses suggesting that Hepatocystis appears to cross species barriers more easily than Laverania. Longitudinal and cross-sectional sampling independently support the hypothesis that mean ambient temperature drives spatiotemporal variation in chimpanzee Laverania infection. Infection probability peaked at similar to 24.5 degrees C, consistent with the empirical transmission optimum of P. falciparum in humans. Forest cover was also positively correlated with spatial variation in Laverania prevalence, consistent with the observation that forest-dwelling Anophelines are the primary vectors. Extrapolating these relationships across equatorial Africa, we map spatiotemporal variation in the suitability of chimpanzee habitat for Laverania transmission, offering a hypothetical baseline indicator of human exposure risk

Predicting range shifts of African apes under global change scenarios

Aim: Modelling African great ape distribution has until now focused on current or past conditions, while future scenarios remain scarcely explored. Using an ensemble forecasting approach, we predicted changes in taxon-specific distribution under future scenarios of climate, land use and human populations for (1) areas outside protected areas (PAs) only (assuming complete management effectiveness of PAs), (2) the entire study region and (3) interspecies range overlap. Location: Tropical Africa. Methods: We compiled occurrence data (n = 5,203) on African apes from the IUCN A.P.E.S. database and extracted relevant climate-, habitat- and human-related predictors representing current and future (2050) conditions to predict taxon-specific range change under a best- and a worst-case scenario, using ensemble forecasting. Results The predictive performance of the models varied across taxa. Synergistic interactions between predictors are shaping African ape distribution, particularly human-related variables. On average across taxa, a range decline of 50% is expected outside PAs under the best scenario if no dispersal occurs (61% in worst scenario). Otherwise, an 85% range reduction is predicted to occur across study regions (94% worst). However, range gains are predicted outside PAs if dispersal occurs (52% best, 21% worst), with a slight increase in gains expected across study regions (66% best, 24% worst). Moreover, more than half of range losses and gains are predicted to occur outside PAs where interspecific ranges overlap. Main Conclusions: Massive range decline is expected by 2050, but range gain is uncertain as African apes will not be able to occupy these new areas immediately due to their limited dispersal capacity, migration lag and ecological constraints. Given that most future range changes are predicted outside PAs, Africa's current PA network is likely to be insufficient for preserving suitable habitats and maintaining connected ape populations. Thus, conservation planners urgently need to integrate land use planning and climate change mitigation measures at all decision-making levels both in range countries and abroad

Population dynamics and genetic connectivity in recent chimpanzee history

Knowledge on the population history of endangered species is critical for conservation, but whole-genome data on chimpanzees (Pan troglodytes) is geographically sparse. Here, we produced the first non-invasive geolocalized catalog of genomic diversity by capturing chromosome 21 from 828 non-invasive samples collected at 48 sampling sites across Africa. The four recognized subspecies show clear genetic differentiation correlating with known barriers, while previously undescribed genetic exchange suggests that these have been permeable on a local scale. We obtained a detailed reconstruction of population stratification and fine-scale patterns of isolation, migration, and connectivity, including a comprehensive picture of admixture with bonobos (Pan paniscus). Unlike humans, chimpanzees did not experience extended episodes of long-distance migrations, which might have limited cultural transmission. Finally, based on local rare variation, we implement a fine-grained geolocalization approach demonstrating improved precision in determining the origin of confiscated chimpanzees