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Foster and Kreitzman - Seasons of Life - Krill and bird breeding
Identifier
020327
Type of Spiritual Experience
Background
Despite climate change, the activity dependencies are being maintained and compensated for………..
A description of the experience
Seasons of Life – Russell G Foster and Leon Kreitzman
French biologists Christophe Barbraud and Henri Weinerskirch found a contradictory trend towards later spring arrival and laying when they examined a 55 year record of arrival and time of egg laying of nine sea bird species kept by generations of scientists at a research station on Adelie Land in eastern Antartica, at a latitude of about 67 degrees south.
Species now arrive at Adelie Land 9.1 days later, on average, and lay eggs on average 2.1 days later than in the early 1950s. However, Barbraud and Weimerskirch were studying records of seabirds that are the top predators in a marine food chain. In eastern Antarctica it seems that the krill population, which is the basis of the marine food chain, is in decline. Seabirds suffer disproportionately from a reduction in food abundance at the bottom of the chain. Consequently, there is micro-evolutionary selection pressure that is favouring the birds arriving a few days later and compressing the pre-egg laying process of territory selection and courtship by seven days. This shift may enable some of the bird species to survive in a declining food environment