As temperatures warm, body sizes are decreasing, but larger-brained species are declining less strongly than small-brained species.

Justin Baldwin

Relative brain size correlates with increased learning ability, increased memory, longer lifespans and more stable population dynamics, in this case, a bigger-brained species of bird might be able to reduce its exposure to warming temperatures by seeking out microhabitats with cooler temperatures, for example.

The authors from that amazing study shared their raw data... which allowed us to add to it and discover more.