Results 151 to 160 of about 5,109 (183)

Methyl mercury: Its effect on eggshell thickness

Bulletin of Environmental Contamination and Toxicology, 1972
The authors have examined the effect of mono- and di-methyl mercury on the shell thickness of two species, the Ring Dove (Streptopelia risoria) and American Kestrel (Falco sparverius). Two clutches (two eggs each) were collected from each pair of doves before the administration of mercury.
D B, Peakall, J L, Lincer
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Thickness of the American woodcock eggshell, 1971

Bulletin of Environmental Contamination and Toxicology, 1973
Eggs or empty shells of the American woodcock were collected from 10 states in 1971 and shell thickness (mean of clutch means) was compared with that of eggs collected from 16 states during the years 1859–1939. The 1971 shells (n=91) from hatched eggs or those containing fully developed embryos were about 10 percent thinner ...
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Eggshell thickness in mallards fed methylmercury

Bulletin of Environmental Contamination and Toxicology, 1980
Eggshell thinning has been linked to impaired reproduction in many wild birds. Previous work of my own and others led me to believe that methylmercury may cause some eggshell thinning in birds. The present study was designed to determine whether methylmercury in the diet of mallards would thin their eggshells and whether it would add to eggshell ...
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Shifts in eggshell thickness are related to changes in locomotor ecology in dinosaurs

Evolution, 2021
Birds share an array of unique characteristics among extant land vertebrates. Among these, external and microstructural characteristics of extant bird eggs have been linked to changes in reproductive strategy that arose among non-avian theropod dinosaurs. More recently, differences in egg proportions recovered in crown birds relative to other dinosaurs
Lucas J. Legendre, Julia A. Clarke
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Bone parameters of thick and thin eggshell lines of chickens

Comparative Biochemistry and Physiology Part A: Physiology, 1984
Comparative measurements of bone parameters were made on chickens from thick and thin eggshell lines that were maintained on a normal diet containing 3.5% calcium, injected i.v. with 45CaCl2 and sacrificed 30 min later. There were no significant differences between shell lines for the following measurements on the left femur: specific gravity, ash wt ...
E G, Buss, R B, Guyer
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Effects of dietary mercury and lead on eggshell thickness in mallards

Bulletin of Environmental Contamination and Toxicology, 1974
Experiments were performed to determine whether mercury and lead in the diet of captive mallards (Anas platyrhynchos) would increase the eggshell thinning above that caused by DDE alone. DDE alone caused a 15% reduction in shell thickness, but neither Pb and Hg contributed significantly to mallard eggshell thinning, nor did these compounds appear to ...
M A, Haegele, R K, Tucker, R H, Hudson
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DDE Residues and Eggshell Thickness in Prairie Falcons

The Journal of Wildlife Management, 1973
The eggshell thickness of prairie falcon (Falco mexicanus) eggs collected in Colorado in 1967-68, and 1972, is related linearily and inversely to the logarithms of the DDE content of the eggs. This relationship is not statistically different from that found in peregrine falcons (F. peregrinus) and brown pelicans (Pelecanus occidentalis).
James H. Enderson, Peter H. Wrege
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A Comparative Study of Eggshell Thickness in Cowbirds and Other Passerines

The Condor, 1987
We directly measured the eggshell thickness of the three brood parasitic Molothrus cowbirds, 17 other icterids, and 13 additional passerines. By correcting these shell thickness measurements for variation attributable to interspecific differences in egg volume, we show that the Molothrus cowbirds lay eggs with shells that are 30% thicker than expected ...
Spaw, Carol D., Rohwer, Sievert
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Reproductive correlates of eggshell thickness in European woodpeckers

Ornis Norvegica, 2008
Woodpeckers excavate their own nesting holes, have small eggs relative to their body size and many species have small clutches. Based on data from the eight European woodpecker species it was found that the mean thickness of eggshells increases with egg volume, whereas large woodpeckers lay smaller eggs with thinner eggshell relative to their body mass.
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Eggshell thickness and porosity in budgerigars and their relationship to hatch‐ability

Journal of Small Animal Practice, 1992
ABSTRACTAs part of an investigation into low chick production in relation to the number of eggs laid by exhibition budgerigars, a study was carried out into the role, if any, of shell thickness and porosity to water vapour. Shell thickness was the same in clear eggs, fertile eggs, those containing dead‐in‐shell embryos and those with desiccated ...
J. R. Baker, R. Baker
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