Thank you Daryl.
Steven I find it interesting how tenuous and nebulous the connection between the data and the conclusions are.
Here is another abstract from Grouse Guy's list:
Scheuhammer, A.M., Bond, D.E., Burgess, N.M., Rodrigue, J., 2003.
Lead and stable isotope ratios in soil, earthworms and bones
A study to discriminate among different possible sources of elevated Pb exposure for American woodcock (Scolopax minor) in eastern Canada is described. Undamaged wing bones excised from young-of-the-year woodcock collected from several locations in southern Ontario, southern Quebec, New Brunswick, and Nova Scotia, Canada, along with soil and earthworm (Aporrectodea tuberculata and Lumbricus rubellus) samples from the same sites, were analyzed for total Pb, and stable Pb isotopes. Ignoring six soil samples with high (> 60 microg/g) Pb concentration from the vicinity of Montreal (QC, Canada), the mean soil-Pb concentration for all sites combined was 19 microg/g (dry wt; n = 64), with a mean 206Pb:207Pb ratio of 1.19, values typical for uncontaminated rural soils in eastern North America. In earthworms, Pb concentrations ranged from 2.4 to 865 (microg/g [dry wt], mean = 24 microg/g). Concentrations of Pb in worms and soils were positively correlated (r = 0.71; p < 0.01), and 206Pb:207Pb ratios for worms and soils were also positively correlated (r = 0.54; p < 0.05). However, most young-of-the-year woodcock with high bone-Pb accumulation (> 20 microg/g) had 206Pb:207Pb ratios substantially different from worms and soils sampled from the same areas, even though woodcock feed extensively on soil invertebrates, especially earthworms. The range of 206Pb:207Pb ratios in wing bones of woodcock with elevated Pb exposure was not consistent with exposure to environmental Pb from past gasoline combustion nor Precambrian mining wastes but was consistent with ingestion of spent Pb shotgun pellets.
What they did for this study:
They measured lead concentrations in earthworms and soil in different areas.
They measured lead concentrations in Woodcock chicks.
They found some chicks with a lead concentration relative higher than the soil and eathworms in that area would indicate they ought to be compared to other chicks in other areas.
They concluded that the difference had to be from lead shot ingestion.
I have sure seen a variety of critters in the craws of the birds I have taken over the years. Don't usually see grasshoppers in the January birds' craws but I frequently find them in November. What if I tested my birds' lead concentrations in June rather than January. Would there be a difference. What about plants? Would one area have identical plants and if they did would the seeds mature at the same time? If they did were the seeds mature at the time of the data collection?
Psssh
Best,
Mike
Last edited by AmarilloMike; 01/10/10 03:34 PM.
