Migrating birds chill at stopovers to save energy

Washington, September 11 (ANI): In a new research, scientists have suggested that migrating birds drop their body temperature at night during stopovers to save energy and build up their reserves faster.

Scientists Michal Wojciechowski and Berry Pinshow carried out the research.

Collecting migrating blackcaps at their stopover site on the Sede Boqer Campus of Ben-Gurion University and near Toron, Poland, Wojciechowski and Pinshow weighed the birds and monitored their body temperatures and metabolic rates as the birds stocked up on fruit supplemented with mealworms.

During the day, the birds' body temperatures hovered around 42.5 degrees Celsius, but as dusk fell, their temperatures began to drop.

The average normal body temperature at night was about 38.8 degrees C, while one particularly skinny individual's temperature plummeted to 33 degrees C.

When the team plotted the birds' body masses against their nocturnal temperatures, the smaller birds' temperatures correlated with their body masses.

Finally, the team looked at the relationship between the birds' temperatures and their metabolic rates and found that the heavier birds dropped their metabolic rates least, while the lightest birds dropped their metabolic rates most.

Some conserved a remarkable 30 percent of their energy by becoming hypothermic.

Knowing that small birds also conserve energy by huddling together for warmth, Wojciechowski and Pinshow suggest that migrating birds may combine both strategies to shorten refuelling stopovers to fatten up fast before hastening on their way. (ANI)