Justin Baldwin

Program: Ecology and Evolutionary Biology

Current advisor: Carlos A. Botero, PhD

Undergraduate university: Hampshire College, 2013

Enrollment year: 2019

Research summary
Adaptations to thermal gradients in birds

I study how birds have adapted to variation in temperature in space and time. I investigate this process across multiple scales of biology: both within species and across species/within families. I have done synthesis work at Washington University, procured funding to acquire novel data on avian brain sizes from museums, and maintain active collaborations outside of WashU. First, I have shown how avian brain size explains variation in phenotypic responses to climate changes. These findings add to a growing body of research that supports the predictions of the cognitive buffer hypothesis, as we showed that North American birds with larger relative brain sizes showed weaker rates of phenotypic change in response to four decades of global warming in their breeding and wintering ranges. Next, I showed that across the global avian Tree of Life, the process of thermal adaptation is inherently multidimensional. To do this, I tested for conformity to Bergmann’s and Allen’s rules in ~ 7000 species of resident, terrestrial birds and showed that although many bird families evince either body size decreases or bill size increases along warming geographic ranges, most families show simultaneous changes in both measures. These simultaneous changes are numerically weak, but by acting at the same time can elicit comparable changes in surface area to volume ratios. We also showed how species traits like bill shape can predict the mode of thermal adaptation, as e.g. specialized bills were associated with conformity to Bergmann’s rule, potentially due to functional constraints on bill shape.

Graduate publications
Baldwin JW, Garcia-Porta J, Botero CA. 2023 Complementarity in Allen’s and Bergmann’s rules among birds. Nat Commun, 14(1):4240. PMCID: PMC10349823

Minakova E, Mikati MO, Madasu MK, Conway SM, Baldwin JW, Swift RG, McCullough KB, Dougherty JD, Maloney SE, Al-Hasani R. 2022 Perinatal oxycodone exposure causes long-term sex-dependent changes in weight trajectory and sensory processing in adult mice. Psychopharmacology (Berl), 239(12):3859-73. PMCID:

Baldwin JW, Garcia-Porta J, Botero CA. 2022 Phenotypic responses to climate change are significantly dampened in big-brained birds. Ecol Lett, 25(4):939-47. PMCID: