Do male "long-distance calls" function in mate defense? A comparative study of long-distance calls in primates

Long-distance calls produced by males are common among vertebrate species. Several hypotheses have been proposed to explain features of male long-distance calls and their phylogenetic distribution in primates, but the putative functions of male long-distance calls have yet to be tested comprehensively. We used phylogenetic comparative methods to investigate hypotheses for the function of male long-distance calls. We focused on the mate defense hypothesis, which states that male long-distance calls function in intra-sexual competition for mates, but we also examined factors involving resource defense, mate attraction, and habitat. Phylogenetic reconstruction of male long-distance calls in 158 primate species indicates that the presence of male long-distance calls is the ancestral state. The carrying distance of male long-distance calls is correlated with the size of the home range, which is consistent with the role of male long-distance calls in defending mates, attracting mates, and defending resources. However, measures of male intra-sexual competition were not associated with the evolution of male long-distance calls. Evolutionary transitions were only partly correlated with factors related to mate attraction. Instead, the strongest correlates of male long-distance calls were activity period, body mass, home range, habitat and some measures of resource defense. Our results are consistent with long-distance call production as a costly signal, but detailed study within species is required to assess these costs and the functions of long-distance calls in individual cases. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/.     

Bromo- and bromochloro-dibenzo-p-dioxins and dibenzofurans in the environment

At least 36 million pounds of brominated flame retardants are used in the U.S. annually. Most if not all of these materials enter the waste stream via landfilled plastic waste, municipal incinerator fly ash, or automotive fluff waste. Analytical methodology is summarized which is suitable for environmental monitoring of these wastes, and the significance of the analytical results is discussed.     

Comparison of ozone uptake and sensitivity between a phytotron study with young beech and a field experiment with adult beech (Fagus sylvatica)

Chamber experiments on juvenile trees have resulted in severe injury and accelerated loss of leaves along with reduced biomass production under chronically enhanced O3 levels. In contrast, the few studies conducted on adult forest trees in the field have reported low O3 sensitivity. In the present study, young beech in phytotrons was more sensitive to O3 than adult beech in the field, although employed O3 regimes were similar. The hypotheses tested were that: (1) differences in O3 uptake were caused by the ontogenetically higher stomatal conductance of young compared to adult trees, (2) the experimental settings in the phytotrons enhanced O3 uptake compared to field conditions, and (3) a low detoxification capacity contributes to the higher O3 sensitivity of the young trees. The higher O3 sensitivity of juvenile beech in the phytotrons is demonstrated to relate to both the experimental conditions and the physiological responsiveness inherent to tree age.     

Long term changes in polychlorodibenzo-p-dioxin concentrations in wood treated with technical pentachlorophenol

Wood samples treated with technical pentachlorophenol (PCP), technical sodium pentachlorophenoxide (NaPCP) and octachlorodibenzo-p-dioxin have been exposed outdoors for periods up to $\text{2}\text{1}\text{2}$ years. Analysis of extracts from the samples show that photolytic reductive dechlorination of highly chlorinated dibenzo-p-dioxins to less chlorinated isomers occurs. However there is no discernible increase in polychlorodibenzo-p-dioxin concentrations in the technical PCP treated wood presumably because further photolytic reactions and volatilisation compete effectively with the photolytic formation. There is no evidence for formation of octachlorodibenzo-p-dioxin (OCDD) in technical PCP treated wood in this study, probably because photolytic destruction and volatilisation compete effectively with formation reactions when the initial OCDD concentration is relatively high.     

Enhanced ozone strongly reduces carbon sink strength of adult beech (Fagus sylvatica) - Resume from the free-air fumigation study at Kranzberg Forest

Ground-level ozone (O₃) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O₃-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O₃ exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O₃ levels. Elevated O₃ significantly weakened the C sink strength of the tree-soil system as evidenced by lowered photosynthesis and 44% reduction in whole-stem growth, but increased soil respiration. Associated effects in leaves and roots at the gene, cell and organ level varied from year to year, with drought being a crucial determinant of O₃ responsiveness. Regarding adult individuals of a late-successional tree species, empirical proof is provided first time in relation to recent modelling predictions that enhanced ground-level O₃ can substantially mitigate the C sequestration of forests in view of climate change.     

An investigation of aqueous activity coefficients at low concentrations

The activity of a chemical in solution determines its tendency to move into other media. At low concentrations (<0.01M) it is generally considered to be linearly related to concentration. A hypothetical model based on the structure of liquid water is discussed which could cause deviations from this linearity in the ppb region, a concentration much lower than that normally investigated thermodynamically, but one of great importance environmentally. Headspace experiments are reported with carbon tetrachloride and chloroform in water at concentrations down to ～10^?3 ppb but no such deviations were discerned.     

Disruption of coastal societies in the Pacific Islands from rapid sea-level fall about AD 1300: new evidence from northern Viti Levu Island, Fiji

This paper reports preliminary findings of a study in northern Viti Levu Island (Fiji) intended to test the model of the AD 1300 Event. This holds that around AD 1250–1350, during the transition between the Medieval Warm Period and the Little Ice Age, there was a rapid climate-driven sea-level fall of 70–80 cm which created a food crisis for coastal dwellers throughout the tropical Pacific Islands and led to conflict and the abandonment of open coastal settlements in favour of those in more defensible locations. Two main areas were targeted—the Ba River Valley and adjoining Vatia Peninsula (plus offshore islands)—and inland/offshore sites in defensible locations, particularly in caves, ridge-top rockshelters, and isolated hilltops, were surveyed and test excavations made. Results show that while some of these sites were established during the AD 1300 Event, most were established shortly afterwards, which is exactly what the model predicts. It is concluded that prehistoric populations in Fiji (and similar island groups) were affected by the food crisis during the AD 1300 Event and did respond in ways that profoundly and enduringly altered contemporary trajectories of societal evolution. This study has great implications for the preservation of the record of prehistoric settlement in Fiji (and other tropical Pacific Island groups) because, as a consequence of this climate-forced migration from coasts to inland/upland sites, large amounts of sediment were released from island interiors and carried to their coasts where they buried earlier settlements or redistributed their material signature. Since European arrival in such places around 150 years ago, a second wave of coastal sedimentation, largely driven by plantation agriculture development had similar effects. The current rise of sea level around Pacific Island coasts is the latest in a series of (largely human) threats to the preservation of their cultural heritage.