Shrinking Birds

“Honey, we’ve shrunk… the BIRDS?”

This is Sandra Tsing Loh with the Loh Down on Science.

Giraffes didn’t grow their long necks overnight — it took MILLIONS of years of adaptation! What if we could see animals adapting to environmental changes – within our own lifetime?

Enter Vitek Jirinec and his team of researchers from Louisiana State University. They examined forty years of rain and temperature data in parts of the Amazon. Then, they analyzed changes in the bodies of local bird species over that same period.

What did they find? Out of the nearly eighty bird species studied, ALL of them decreased in size! The birds consistently shrank over each decade.The trend shows that the largest drops in size occurred after hotter, dryer seasons. 

The researchers think this could be due to the stress of heat, or to less food availability. But these changes show the birds are LIGHT on their feet, quickly adapting!

Now, how do we fix the laser machine and unshrink them?

Reference: Jirinec, V., Burner, R. C., Amaral, B. R., Bierregaard Jr, R. O., Fernández-Arellano, G., Hernández-Palma, A., … & Stouffer, P. C. (2021). Morphological consequences of climate change for resident birds in intact Amazonian rainforest. Science Advances, 7(46), eabk1743.