Elevated dentine-lead levels in deciduous teeth collected from remote first nation communities located in the western James Bay region of northern Ontario, Canada.

Teeth were collected from First Nation schoolchildren inhabiting the remote western James Bay region of northern Ontario, Canada. Lead levels in dentine chips were determined by graphite furnace atomic absorption spectrometry, for naturally exfoliated deciduous teeth. Within exfoliated teeth (one tooth supplied per person), no significant differences in lead concentrations between tooth type were found (P = 0.36). The mean lead concentration of exfoliated teeth of 9.2 microg g(-1) dry weight (N = 61) from this remote region was comparable to levels reported by others for children inhabiting urban centers or residing near smelters. Further, 24.6% (N = 15) had elevated dentine-lead levels ( > 10 microg g(-1)). Lead levels in soil, water, and air have been reported as being low and unimportant sources of exposure for people of the western James Bay area. Evidence is reviewed suggesting that lead contaminated game meat was one source of environmental lead exposure. Consumption data indicate that wildlife is still an important food source for First Nation people of the western James Bay region; 98% (46/47) of the children surveyed consumed some type of wild meat.

Non-random mating in classical lekking grouse species: seasonal and diurnal trends.

This paper is the first to integrate both field and theoretical approaches to demonstrate that fertility benefits can be a direct benefit to females mating on the classical lek. Field data collected for male sharp-tailed grouse (Tympanuchus phasianellus), a classical lekking species, revealed potential fertility benefits for selective females. Adult males and individuals occupying centrally located territories on the lek were found to have significantly larger testes than juveniles and peripheral individuals. Further, using empirical data from previously published studies of classical lekking grouse species, time-series analysis was employed to illustrate that female mating patterns, seasonal and daily, were non-random. We are the first to show that these patterns coincide with times when male fertility is at its peak.