We want to understand the big patterns of life on Earth and ensure that today’s incredible biodiversity will persist into the foreseeable future. Our research focuses on the best places on Earth—mountains— and most of us have an inordinate fondness for our feathered friends. The central theme of research in the Mountain Bird Lab is to understand how montane birds are responding to climate change.

global change — range changes — range limits — species interactions — behavior — speciation — trait evolution

Freeman contact information

I am an Assistant Professor at Georgia Tech in Atlanta, where the players play

When on the job, you can find me teaching about biology and statistics (and giving extra credit for haikus & memes), mentoring students, on intense fieldwork trips, running field experiments, in museum collections, analyzing citizen science datasets, and comprehensively searching the literature. Or perhaps more likely, hard at work writing, re-writing, and re-writing once more.

bfreeman47@gatech.edu | @BenGFreeman1 | Google Scholar

MY favorite photo - a rufous-tailed jacamar about to emit a pellet of indigestible insect parts

MY favorite photo that i have taken - a rufous-tailed jacamar about to emit a pellet of indigestible insect parts

Latest news:

  • Feb 2024 — Overdue update: Congrats Pranav for being awarded a Rufford grant for his research on Himalayan bird responses to climate change. Welcome to Sam Jones joining the lab as a postdoc (big things happening soon with the Mountain Bird Network). Ben was busy this month giving seminars (Kent State & UGA) and public talks (Georgia Ornithological Society & Birds Georgia). Feels like spring the past couple weeks, a reminder to get everything ready for fieldwork.

  • August 2023 — Arrival to Atlanta, and a warm welcome to Pranav!

  • June 2023 — lovely fieldwork resurveying birds in BC old growth stands, soon we will know if Pacific NW birds are are on the escalator to extinction.

  • May 2023 — Species on the Move conference was delightful, inspiring and professionally fulfilling. Great to meet lots of folks in person and think about all sorts of future projects.

  • April 2023 — Mountain Bird Network - please let me know if you want to join this effort.

  • January 2023 — new year, two new papers. First, in Journal of Biogeography: undergrad Geoff Lau led the analysis of 2268 blood samples collected along a ridge-to-reeftop elevational gradient that we screened for parasites. I had thought infection rates would be much higher in the lowlands, but that’s not really the case (just a tiny bit). Instead, closely related species had similar infection levels no matter which elevational zone they lived in. Story about this paper — and about how I got malaria — in this twitter thread. I have no idea how some species deal with near 100% infection rates. What, if anything, is the fitness cost of infection?? Second, in Evolution: I led a paper where we show that, for Andean birds, divergence in sexual traits is predictable but divergence in ecological traits is not. I had wanted to write this paper for a looong time (see this Twitter thread), and am glad to see this come out.

  • Fall 2023 — taught Evolutionary Ecology in person, mostly stayed offline

  • July 2022 — New paper gets the cover of Science!

  • June 2022 — Had a great time at AOS-BC conference in Puerto Rico, where I gave a plenary presentation and was pleased to be one of the recipients of the Ned K Johnson Early Investigator Award. Honored, and delighted to see so many colleagues and friends in person.

  • February 2022 — Where on Earth is evolution the fastest? My new paper in Ecology Letters tests these ideas with data. Turns out that evolution is faster in the temperate zone, both for bird beaks and in a meta-analysis. This means we can reject several hypotheses for the latitudinal diversity gradient that propose high tropical diversity results from faster tropical evolutionary rates. #RapYourAbstract here. Also pleased to be on the big “traits for all the birds” paper in the same issue.

  • January 2022 — New year, new papers. I’m really proud of this one in Proceedings B. I led a comparative study of song evolution based on intense fieldwork — we did thousands of playback experiments over several years to arrive at some important conclusions about song evolution in birds. Check out the twitter thread. I’m also an author on a cool new paper about the evolution of tropical montane birds.

  • October 2021 — Excited to be featured in Thor Hansen’s new book “Hurricane Lizards and Plastic Squid: The Fraught and Fascinating Biology of Climate Change”. Tore through this book, fun (and strange) to read about myself, but also many other great stories, all well told. Highly recommended!

  • September 2021— My pitohui video is going viral on Reddit & Twitter again, which means I get to answer people’s many questions about the fascinating biology of poisonous birds. Nothing like poisonous birds to get people’s attention!

  • August 2021 — The “Evolutionary ecology of mega-diverse tropical montane avifaunas” symposium at virtual AOS/COS symposium went really well. I enjoyed putting this symposium together; thanks to all participants.

  • July 2021 — The Mountain Bird Network got off to a great start in its inaugural year. I am excited to take this to the big time, starting with an expansion for next year. Check out this good press from the Albuquerque Journal.

  • June 2021 — Thanks Avneet Chhina for inviting me to talk about evolution in action (and birds of course) with Surrey high school students. I had a great time and was particularly impressed by the student’s many good questions.

  • June 2021 — New paper out in TREE about the latitudinal taxonomy gradient (LTG) - this should be a good one to spark discussions. We make three points: 1) There is a LTG - that is, a taxonomic debt in the tropics, with many species in the tropics that are not yet recognized but relatively few not-yet-recognized species in the temperate zone; 2) The LTG is a source of bias for pretty much any study of latitudinal variation in ecological and evolutionary processes; 3) We can design our studies in ways to minimize this source of bias

  • May 2021 — Was a pleasure to give a keynote plenary for the Congreso Peruano de Ornitología - thanks for the invitation to talk about my research on the “escalator to extinction”

  • May 2021 — Paper now up in early view at Ecology Letters. And I’ve done a #RapYourAbstract for it, watch on Twitter. and… MC Hammer approves! thanks Hammer, that really made my day

  • March 2021 — Another paper accepted in Ecology Letters (here’s the Biorxiv version): Biogeography predicts how montane species are changing their elevational ranges as temperatures rise. Species are on the move at low latitudes, where tropical species are, on average, closely tracking recent temperature increases by shifting their distributions upslope. In contrast, temperate species’ elevational ranges are shifting upslope at rates that lag far behind the pace of warming. This has many conservation implications; for example, the “escalator to extinction” may run faster in the tropics. 

  • February 2021 — Paper accepted in Ecology Letters (here’s the Biorxiv version): Where is evolution fastest? In the temperate zone, not the species-rich tropics. Staying busy giving public talks this month as well, with several already scheduled — we take crows seriously here in Vancouver.

  • January 2021 — Devastated to learn that Gonzalo Cardona Molina, Colombian conservationist largely responsible for the back-from-the-brink conservation success of the Yellow-eared Parrot in his hometown of Roncesvalles, was assassinated. Gonzalo invited me to visit him in 2008; he welcomed me into his home and proudly showed me the nesting parrots he cared for so deeply. I am inspired by Gonza’s success and more so by his sincerity - he just really, truly cared about the parrots, and was tireless in helping their population recover.

  • January 2021 — Just presented at Virtual Asilomar (you can watch it on Youtube, mine starts ~ 1:40), and looking forward to talking to the Stanley Park Ecology Society this week.

  • November 2020 — New paper in Am Nat! Check out my #RapYourAbstract on Twitter. The big idea here is that evolution can dampen ecological patterns. We show that daily nest predation rates are similar in the tropics and temperate zone, counter to the prevailing idea that nest predation is more severe in the tropics. We argue that the “flat” latitudinal gradient in daily nest predation rates is in part due to adaptation: in a world with no evolution, tropical rates of daily nest predation would be higher than temperate rates, but local adaptation has reduced this difference.

  • September 2020 — another full online conference experience. I was pleased to talk about the biogeography of range shifts in a mini-symposium on Humboldt Day. Quite convenient to teach a course, give a talk and attend a different institution’s lab meeting in the same day!

  • August 2020 — I was full of trepidation about online only conferences. But… I kind of liked all-online NAOC (bird conference). Could wake up, tune in, watch a talk over breakfast. The logistics were just so easy. I had a great audience for my talk and got to see so much cool science. Big thanks to organizers. I would be into online-only conferences every other year…

  • June 2020 — Wrapping up teaching Biostatistics. Online, 120 students. In a short, six-week long summer session. I was apprehensive about teaching this course at this moment, but I altogether enjoyed the experience. It was consuming. We purposely were VERY available on course discussion board and over Collaborate Ultra, a zoom equivalent. So big effort, but also rewarding. Though it still feels weird that I have no clue what anyone looks like, as students did not turn on their videos during class, lab or office hours…

  • May 2020 — New preprint: I’m really excited about this one. We show that tropical montane species are tracking recent temperature changes much better than are temperate zone montane species. This pattern holds true for resurvey data AND for tree plot data. This means that the escalator to extinction is running fast in the tropics, but not in the temperate zone. Great collaboration with Yiluan Song, Ken Feeley & Kai Zhu.

  • April 2020 — My twitter post about Hooded Pitohuis went viral. Surprised and delighted; people really loved learning that a bird could be poisonous.

  • March 2020 — New paper in Nature Communications. Are species interactions strongest in the tropics? We use longline fisheries data to estimate predation in the world’s oceans. Turns out predation is highest in the temperate zone. What’s more, predation pressure is inversely related to species richness of fishes in the open ocean. These results challenge longstanding explanations for the latitudinal diversity gradient. I also like this news piece, which uses our original title…

  • February 2020 — Great to give a seminar at SFU; special thanks to Arne Mooers for the vigorously delivered poetic introduction

  • January 2020 — Big new paper on bird traits just published in Nature Ecology & Evolution - morphological data for ALL THE BIRDS reveals lots of interesting things, including widespread convergence in form-function relationships (think toucans & hornbills, pittas & antpittas, etc) ! Plus presented my research on latitudinal gradients in species interactions & trait evolution at the Am Nat standalone meeting, where I talked science with lots of good folks. Great way to kick off the new year.

  • November 2019 — and the Ecography paper gets the cover! Great photo from co-author Joe Tobias. And last weekend’s EcoEvo Retreat was a smashing success, with 125 participants. I was particularly pleased that our first inaugural poetry reading went over well - thanks to all poet participants for your haikus, limericks, etc.

  • October 2019 — New paper in GEB. I thought lower elevation species were better competitors than their higher elevation relatives, but I was wrong. Also: had a great time talking about the weird and wonderful birds of the Amazon with BRASA UBC, the Brazilian student club on campus. Thanks for the invite!

  • September 2019 — I am co-organizing the EcoEvo Retreat & registration is now open! If talking about science in old growth cedar forest is your jam, consider joining our merry collective of biologists from various BC universities. Register at https://ecoevoretreat.wordpress.com/, and classy poster available here.

  • July 2019 — New paper in Ecography. We ask why closely related bird species sometimes overlap in range along mountain slopes & sometimes do not. Turns out behavior is key - species that fiercely defend territories tend not to overlap with their relatives.

  • June 2019 — Come out to Lynn Headwaters Regional Park on June 15 to hear me talk about ravens & all their fascinating behaviors (& go hiking of course).

  • May 2019 —New preprint up - check it out. Darwin thought that lower latitude/elevation species are generally better competitors than related higher lat/elev species. MacArthur did too. Often phrased as “competition limits species’ warm range edges.” I’m here to report mixed evidence for this idea (from a meta-analysis of behavioral competition between related lower & upper elevation species). Also, early May = spring migration, NBA playoffs + Champions League, damn.

  • April 2019 — We expect distantly related species to look pretty different. But in woodpeckers, distantly related species often look nearly identical - big time mimicry in birds! Out now in Nature Communications, a project helmed by Eliot Miller & Rusty Ligon. Also, looking forward to talking about birds and climate change at Vancouver Public Library on April 16 - should be a great event!

  • March 2019 —Lots going on, writing & revising & submitting & plotting new schemes. Proud to have helped Ethan Linck on his ambitious project to test Mayr’s ideas about speciation & diversity build-up in tropical mountians—using specimens collected by Mayr himself nearly a century ago! Now posted on Biorxiv.

  • December 2018 — Just back from Bogotá where I gave a keynote presentation at the Congreso Colombiano de Zoología. It was great to meet so many folks (and to return to Colombia for the first time in 8 years)- the congress showcased a lot of exciting science.

  • October 2018 — Big news, new paper out in PNAS. We show that global warming sets in motion an “Escalator to Extinction” for mountain birds. Birds on a Peruvian mountain have (1) shifted upslope associated with recent warming, (2) high elevation species are getting squeezed into smaller areas, (3) high elevation species are declining in abundance, and (4) some previously common high elevation species have disappeared. We view our study, conducted along an 8 km trail, as a miniature real-world model of the same processes likely occurring on mountain slopes throughout the tropical Andes (and perhaps throughout the global tropics). Great coverage, including from Ed Yong in The Atlantic, the AP, the BBC, and Yale e360.

  • September 2018 -- New paper out in Global Ecology and Biogeography! We show that across the globe, high elevation species are shrinking in range size as they shift upslope in response to warming temperatures. Also, we find no support for the idea that temperature is a more important driver of cool range limits: average shifts were similar at species' warm vs. cool limits. Big thanks to co-authors Julie Lee-Yaw, Jennifer Sunday and Anna Hargreaves. This was a real collaborative effort, hatched in the hallways of the Biodiversity Research Centre, and it is so nice to have this out!

  • July 2018 -- New paper out in The Auk: Ornithological Advances! We show that crows chase ravens all the time (mostly in spring) and usually in groups - they use their social behavior to gain the upper hand on a bigger relative. Big thanks to all the citizen scientists who provided the data. Nice coverage in National Geographic , Cornell Lab of Ornithology, the Vancouver Courier, Global News, the National Post, and many other places (including the NRA!). I dig this Gizmodo piece.

  • June 2018 -- My new paper out in Journal of Biogeography. We show that most species are not common in the center of their range and rare at their range edges for New Guinean birds distributed along a mountain slope.

  • May 2018 -- Had a great time giving a public lecture about crows and ravens for the Beaty Biodiversity Museum's Way Cool series. Invigorating to talk about science to an all-ages audience, and gratifying to have an engaged & packed room on a sunny Sunday!

  • March 2018 -- Honored and pleased to receive a Killam Postdoctoral Fellow Research Prize. There are only two awardees per year for this campus-wide competition for UBC postdocs, and it comes with the princely sum of $5,000!

  • March 2018 -- Nice to see Benjamin Van Doren's paper out in Wilson Journal of Ornithology. It's a terrific example of carefully analyzing recordings of songs to help inform species limits, and the genetic data is the icing on the cake.

  • January 2018 -- I just came across this nice write-up in Frontiers in Ecology and the Environment covering our research -- playback experiments can help us understand species limits in birds.

  • December 2017 -- Congrats to Graham Montgomery and Benjamin Van Doren for getting papers from their undergrad careers accepted at Wilson Journal of Ornithology. It takes a lot of dedication to see your project all the way through to publication!

  • September 2017 -- Great to see our study just published in The Auk getting some publicity. We present data from playback experiments that suggests 21 populations of Neotropical birds deserve species status (they ignore song from related populations). Here is a nice write-up in Discover Magazine. And check out this segment on the Discovery Channel Canada (starts at 19:50) featuring a number of Graham's nice bird photos. We even made it into Lonely Planet!

  • July 2017 - Song learning is associated with slower evolution of song divergence in Neotropical birds. This does not support the idea that learning speeds speciation. Read more in Evolution

  • March 2017 - Great trip to the Field Museum in Chicago to measure tons of birds (and give a seminar). Inspiring place to measure morphological divergence between closely related birds and contemplate the grandeur of life.