| reduced oxygen diffusion across the shell of gray gull (larus modestus) eggs. | gray gulls, larus modestus, nest 1500 m above sea level in northern chile's atacama desert, one of the driest in the world. their eggshell gas permeability, one third of that found in other larus species, is an adaptation that reduces water loss, but at the expense of oxygen diffusion into the air cell with resultant hypoxia and reduced metabolic rate. this contrasts with characteristics found in birds nesting at very high altitudes where oxygen diffusion across the egg shell is maximized at the ... | 2000 | 15696681 |