E35. Eighteen species of small brown bird on a pile of volcanic rock have taught us more about how evolution actually works than almost anything else on Earth. Not because Darwin figured them out. He didn't. Because a handful of scientists went back, banded every bird on one island, and watched it happen in real time. Scott heads to the Galapagos with Dr. Erik Enbody, Assistant Professor of Computational Biology at Cornell University, to find out how one ancestor became eighteen, why the beak is the only thing worth looking at, and what happens when species that aren't supposed to interbreed start swapping genes anyway.

In this episode you'll hear about:

• The island so small you can band every bird on it, and the drought that killed almost all of them
• One gene that explains 40% of beak size, when nothing in human height explains even 1%
• The finch that does something mind-blowingly villainous and what it says about how far evolution will go

All audio, video, and images in this episode are either original to Okay, But... Birds (© Okay Media, LLC) or used under license/permission from the respective rights holders. Media from the Macaulay Library is used courtesy of the Cornell Lab of Ornithology as follows:

• Large Ground-Finch audio contributed by Robert I. Bowman, ML85965
• Common Cactus-Finch audio contributed by Robert I. Bowman, ML86715
• Small Tree-Finch audio contributed by Robert I. Bowman, ML85464
• Vegetarian Finch audio contributed by Robert I. Bowman, ML82506
• Galapagos Mockingbird audio contributed by Robert I. Bowman, ML45963
• Española Mockingbird audio contributed by Herb Elliott, ML638777433
• Floreana Mockingbird audio contributed by Robert I. Bowman, ML85455
• San Cristobal Mockingbird audio contributed by Arnoud B. van den Berg, ML28656
• Palm Tanager audio contributed by Curtis Marantz, ML88937
• Blue-footed Booby audio contributed by Robert I. Bowman, ML85906
• Vampire Ground-Finch audio contributed by Robert I. Bowman, ML86756
• Woodpecker Finch audio contributed by Robert I. Bowman, ML82522
• Paradise Tanager audio contributed by Curtis Marantz, ML127399
• Galápagos Sea Lion audio contributed by Arnoud B. van den Berg, ML125020

E34. Not all birds build one, but for the ones that do, a nest has a single job and a shockingly wide range of ways to get it done. Dr. Vanya Rohwer, Curator of Birds and Mammals at the Cornell University Museum of Vertebrates, joins Scott to walk the far end of that spectrum, from nests made entirely of spit to a colony structure heavy enough to snap the tree it sits in.

In this episode you'll hear about:

• The complete and comical inventory of one hamerkop nest, read aloud, contents included
• What a bird does when you hand it a nest somebody else already built
• Why a shed snakeskin in a tree cavity is a calculated decoration

New episodes every Thursday. If the show is doing it for you, leave a rating or hit follow.

All audio, video, and images in this episode are either original to Okay, But… Birds (© Okay Media, LLC) or used under license/permission from the respective rights holders. Bird media from the Macaulay Library is used courtesy of the Cornell Lab of Ornithology as follows:

• American Robin audio contributed by Bob McGuire, ML206448
• Baltimore Oriole audio contributed by Bob McGuire, ML219606
• Black-legged Kittiwake audio contributed by Roger Charters, ML202491
• White-nest Swiftlet audio contributed by Arnoud B. van den Berg, ML36421
• Cliff Swallow audio contributed by James (Jim) Holmes, ML92053871
• Chimney Swift audio contributed by Wil Hershberger, ML107413
• Hamerkop audio contributed by Anonymous, ML97562
• Eastern Whip-poor-will audio contributed by Bob McGuire, ML195774
• Montezuma Oropendola audio contributed by David L. Ross Jr., ML215446
• Western Grebe audio contributed by Bob McGuire, ML195029
• Rufous Hornero audio contributed by Mike Andersen, ML132447
• Northern Yellow Warbler audio contributed by Wil Hershberger, ML516692
• Sociable Weaver audio contributed by Jacob Henry, ML637193738
• Great Crested Flycatcher audio contributed by Wil Hershberger, ML94314
• Blue-gray Gnatcatcher audio contributed by Wil Hershberger, ML534430
• White-breasted Nuthatch audio contributed by Bob McGuire, ML306062

E33. When the air temperature climbs past a bird's own body temperature, staying cool stops being free and starts to cost them water they may not have. Dr. Blair Wolf, University of New Mexico, has spent his career studying how desert birds survive heat that should kill them, and what happens when it finally gets too hot.

In this episode you'll hear about:

• Why some backyard birds can shrug off oven-like temperatures while others just a few feet away don't make it
• The strange, water-saving trick birds use to dump heat without a single drop of sweat
• What the birds dying in these heatwaves are trying to tell us about what's coming

All audio, video, and images in this episode are either original to Okay, But... Birds (© Okay Media, LLC) or used under license/permission from the respective rights holders. Bird media from the Macaulay Library is used courtesy of the Cornell Lab of Ornithology as follows:

• White-winged Dove audio contributed by Raphaël Nussbaumer, ML571978241
• Verdin audio contributed by Bob McGuire, ML197163
• Black-throated Sparrow audio contributed by James (Jim) Holmes, ML573935831
• Black-throated Sparrow video contributed by Benjamin Clock, ML483211
• Mourning Dove audio contributed by James (Jim) Holmes, ML583603101
• Mourning Dove audio contributed by Anonymous, ML658417476
• Palm Cockatoo audio contributed by Emma Greig, ML201266
• Rosy-faced Lovebird audio contributed by Derek Solomon, ML168222
• Common Eider audio contributed by Bob McGuire, ML235534