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821.
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G Chamberlain 《BMJ (Clinical research ed.)》1991,303(6795):178-181
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Michael J. Chamberlain Blake A. Grisham Jennifer L. Norris Norman J. Stafford III Frederick G. Kimmel Michael W. Olinde 《The Journal of wildlife management》2012,76(5):907-910
Spring harvest is a primary mortality factor for male eastern wild turkeys (Meleagris gallopavo silvestris), but the relationship between spring harvest regimes and annual survival is not well understood. We banded 462 male wild turkeys from 1989 to 2007 in southeastern Louisiana to estimate annual survival and band recovery rates relative to spring harvest. We evaluated these parameters under a liberal harvest season (3-bird limit; 1989–1997) and a reduced conservative harvest season (2-bird limit; 2000–2007). Estimated recovery rates during the liberal season were 0.75 (SE = 0.05) for adults and 0.63 (SE = 0.04) for juveniles, and recovery rates during the conservative season were 0.61 (SE = 0.04) and 0.48 (SE = 0.05) for adults and juveniles, respectively. Annual survival averaged 0.16 (SE = 0.05) and 0.43 (SE = 0.05) for adults and juveniles, respectively, during the liberal season. Conversely, during the conservative season, annual survival averaged 0.31 (SE = 0.05) and 0.56 (SE = 0.05) for adults and juveniles, respectively. Our findings suggest that bag limit reductions combined with a reduction in season length contributed to a 2-fold increase in annual survival for male wild turkeys. We contend that male wild turkeys were likely over harvested on our study area during the liberal harvest season, which contributed to exceptionally low annual survival rates. Managers should attempt to assess survival rates of male wild turkeys in harvested populations to properly manage spring harvest and develop appropriate harvest limits. © 2012 The Wildlife Society. 相似文献
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The antibody state of a population aged 6 months to 88 years to poliovirus types 1, 2, and 3 was determined by examining 919 sera collected in Lancashire, London, and southern and south-east England. In subjects aged over 2 years the immune state was surprisingly uniform, although the older patients had probably acquired practically all their antibodies as a result of natural infection and those under 16 through vaccination. at least 95% had detectable antibodies to at least one poliovirus type and about 60% to all three types, with the exception of a cohort of children born between 1963 and 1968, in whom the proportions were about 80% and 40% respectively. These children were born around the time of the changeover from inactivated to oral vaccine, when immunisation rates were low and there was confusion over the number of doses required. These results indicate that a complete course of vaccine or a booster dose at or around school-leaving age is necessary. 相似文献
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G Chamberlain 《BMJ (Clinical research ed.)》1991,303(6794):111-115