A change in the diet of seabirds may be making them less intelligent

Birds hit by climate, diet shift

A change in the diet of seabirds may be making them less intelligent and lowering their chances of survival and breeding, a new study shows.

Scientists used lab experiments to mimic changes observed in the diets of kittiwakes in the Bering Sea - changes probably caused by a warming ocean.

Chicks given a diet low in lipid-rich fish were less able to find food.

The RSPB comments that changes in the diets of seabird chicks can affect their chances of survival.

The 1980s saw the start of a decline in populations of red-legged kittiwakes on the Pribilof Islands in the south-eastern Bering Sea, off the coast of Alaska.

Numbers roughly halved over two decades.

The cause has been unclear, though scientists have documented a change in their diet which occurred around the same time...

The cause of this dietary adjustment may be related to climate change, with rising temperatures documented in the Bering Sea at that period perhaps driving the movements of fish populations.

To investigate what impact a forced switch to a low-lipid regime might have on the development of red-legged kittiwakes, the Kitaysky lab designed experiments to explore the effects of various diets.

Twenty kittiwake chicks were hatched in captivity and assigned randomly to four fish diets: high-volume high-lipid, high-volume low-lipid, low-volume high-lipid, and low-volume low-lipid.

At the age of 47 days, the birds began learning to associate food with containers having lids of various colours.

Those which had been fed a high-lipid diet learned quickly and remembered which containers to go for; those on a low-lipid regime did not learn to discriminate between the various colours.

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If true, it raises the question how this "diet-to-intelligence" question affects other species where diets have drastically changed due to ecological change.

Fascinating stuff.