Environmental influences on an exploited anadromous Arctic charr stock in Labrador

Arctic charr Salvelinus alpinus at Nain, Labrador, were influenced by recent variability in measured environmental variables and able to mitigate partially the effects of past conditions in a single year. Weather conditions prevailing during the first winter and sea migration life-stages also exerted significant influence on measured age and weight characteristics and are argued to play a role in determining the population dynamics of exploited stocks.     

Discerning devotion: Testing the signaling theory of religion

Religious rituals often entail significant investments of time, energy, and money, and can risk bodily harm. Instead of being evolutionarily inexplicable, such costly religious acts have been argued to be honest signals of commitment to the beliefs and values of the community, helping individuals establish good reputations and foster trusting, cooperative relationships. Most tests of this hypothesis have evaluated whether religious signalers are more prosocial; here I investigate whether signal receivers actually perceive religious signalers as such. I do this with data collected over 20 months of ethnographic fieldwork in two villages in South India, where Hindu and Christian residents engage in different modes of religious practice, including dramatic acts of firewalking and spirit possession as well as the more subtle but consistent act of worshipping at a church or temple each week. Each mode of religious practice is found to be informative of a distinct set of reputational qualities. Broadly speaking, in the long term, individuals who invest more in the religious life of the village are not only seen as more devout, but also as having a suite of prosocial, other-focused traits. In the short term, individuals who perform greater and costlier acts in the annual Hindu festival show a slight increase in the percent of villagers recognizing them as physically strong and hardworking. These results suggest that people are attending to the full suite of religious acts carried out by their peers, using these signals to discern multiple aspects of their character and intentions.     

Ecotones and fluvial regimes in arctic lotic environments

The fluvial regime in arctic streams is influenced by size of stream, the presence and storage capacity of lakes in the drainage basin, groundwater, and permafrost. Exchange of material with terrestrial environments depends on the season and is more or less suspended in winter. Permafrost and water storage in ice and snow control run off and erosion. Damage to vegetation by flooding, fire, animal or human activity can affect the permafrost and result in rapid erosion. Living space and conditions in lotic environments are modified by ice and during break up are very labile. Fish and benthic organisms in streams have behavioural and physiological adaptations which allow them to benefit from the wide range of river and stream environments found in the arctic and to tolerate the range of seasonal conditions. Ecotones are weakly developed in arctic streams and are of minor functional significance. Only farther south does riparian vegetation begin to play a role in regulating stream processes and not until south of the tree line can ecotones be considered important modulators of fluvial environments.