The Field Guides

• Ep. 71 - The Field Guides Go Crikey!

  The guys return to Everglades National Park, again looking for a predator that Daniel wants to get too close to: the American Crocodile (Crocodylus acutus). Listen in as Daniel shares some research, busts croc-related myths, and Steve probably gets a little too excited about how crocs deal with salt water. Bill doesn’t have much to say, but he’s there, too. Enjoy!This episode was recorded on January 7, 2025 on the Bear Lake Trail in Everglades National Park. The last bit where the guys find the croc was also recorded in the Park, at the Flamingo Marina.Episode Notes and LinksAs promised during the episode, Steve is looking into how crocs process and excrete excess salt. As soon as he gets to the bottom of it, we’ll share it here.In the meantime, here’s what Bill found when he asked DeepSeek: Crocodiles, like many other marine and estuarine reptiles, have specialized salt glands to help them excrete excess salt from their bodies. These glands, known as salt glands or lingual glands (located on their tongues), actively transport salt ions (primarily sodium and chloride) from their bloodstream into the gland ducts. The salt is then excreted as a concentrated saline solution, which is expelled from the body.Crocodiles do not chemically change the salt (sodium chloride) into something else. Instead, they filter and concentrate it, allowing them to maintain proper electrolyte balance in their bodies, especially when living in saltwater environments. This process is crucial for osmoregulation, as it prevents dehydration and helps them survive in both freshwater and saltwater habitats.In summary, crocodiles excrete salt in its original form (sodium chloride) but in a highly concentrated solution, rather than transforming it into a different substance.Sponsors and Ways to Support UsGumleaf Boots, USA (free shipping for patrons)Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.Support us on Patreon.Check out the Field Guides merch at our Teespring store. It’s really a great deal: you get to pay us to turn your body into a billboard for the podcast!Works CitedAdmin, CrocAttack. “Database.” CrocAttack, CrocAttack, 17 July 2023, crocattack.org/database/. Balaguera-Reina, S. A., M. Venegas-Anaya, V. Beltrán-López, A. Cristancho, and L. D. Densmore III 2018. Food habits and ontogenetic dietary partitioning of American crocodiles in a tropical Pacific Island in Central America. Ecosphere 9(9):e02393. 10.1002/ecs2.2393Briggs-Gonzalez VS, Basille M, Cherkiss MS, Mazzotti FJ. American crocodiles (Crocodylus acutus) as restoration bioindicators in the Florida Everglades. PLoS One. 2021 May 19;16(5):e0250510. doi: https://pubmed.ncbi.nlm.nih.gov/34010342/Grigg, Gordon C., et al. Biology and Evolution of Crocodylians. Comstock Publishing Associates, a Division of Cornell University Press ; CSIRO Publishing, 2015. Mazzotti Frank J. , Balaguera-Reina Sergio A. , Brandt Laura A. , Briggs-González Venetia , Cherkiss Mike , Farris Seth , Godahewa Avishka 2022. Natural and Anthropogenic Factors Influencing Nesting Ecology of the American Crocodile in Florida, United States. Frontiers in Ecology and Evolution Vol. 10. https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2022.904576 ISSN=2296-701XMazzotti, F.J. The American Crocodile in Florida Bay. Estuaries 22, 552–561 (1999). https://doi.org/10.2307/1353217Mazzoti, Frank. “American Crocodiles (Crocodylus Acutus) in Florida.” Myfwc.Com, University of Florida IFAS Extension, myfwc.com/media/1847/americancrocodilesinfl.pdf. Accessed Dec. 2024. Villegas, Alejandro, & Schmitter-Soto, Juan Jacobo. (2008). Feeding habits of the American crocodile, Crocodylus acutus (Cuvier, 1807) (Reptilia: Crocodylidae) in the southern coast of Quintana Roo, Mexico. Acta zoológica mexicana, 24(3), 117-124. Recuperado en 30 de enero de 2025, de http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0065-17372008000300008&lng=es&tlng=en.

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• Ep. 70 - Saving the Blue Iguana

  This month, we head to the tropics and meet the Blue Iguana of the Cayman Islands! This endangered lizard is found nowhere else on the globe save for the island of Grand Cayman in the Caribbean, and just two decades ago, it’s likely there were fewer than 25 animals remaining in the wild. This was a species that was functionally extinct, but thanks to the herculean efforts of a dedicated group of people, the Blue Iguana (Cyclura lewisi) has been brought back from the brink, with over 1000 iguanas now roaming the dry, rocky forests of Grand Cayman. In July of 2024 Bill traveled there to interview Fred Burton, the man many people credit as the main driver behind the effort to save this endemic species.This episode was recorded on July 25, 2024 at the Queen Elizabeth II Botanic Park, North Side, Grand CaymanEpisode Notes and LinksFind ourt more about conservation of the Blue Iguana by visiting the National Trust for the Cayman Islands.If you want to support efforts to help the Blue Iguana, you can donate here.Check out Fred’s book, The Little Blue Book: A Short History of the Grand Cayman Blue IguanaIf you ever find yourself in Grand Cayman, we can’t recommend enough that you visit the Queen Elizabeth II Botanic Park, home to the Blue Iguana captive breeding program.Sponsors and Ways to Support UsGumleaf Boots, USA (free shipping for patrons)Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for this episode.Support us on Patreon.Check out the Field Guides merch at our Teespring store. It’s really a great deal: you get to pay us to turn your body into a billboard for the podcast!Works CitedBurton, F.J., 2004. Battling extinction: A view forward for the Grand Cayman Blue Iguana (Cyclura lewisi). Iguana, 11(4), pp.232-237.Burton, F.J., 2005. Restoring a new wild population of Blue Iguanas (Cyclura lewisi) in the Salina Reserve, Grand Cayman. Iguana, 12(3), pp.166-174.Burton, F.J., 2011. Population restoration for a critically endangered reptile—the Grand Cayman blue iguana (Cyclura lewisi). Reptiles Australasia, 1, pp.35-44.Chan, N., Shen, Z., Mannion, A., Kurnick, S., Popescu, I.S., Burton, F.J., Calle, P.P. and Fox, J.G., 2021. Helicobacter cyclurae sp. nov., isolated from endangered blue iguanas (Cyclura lewisi). Frontiers in Ecology and Evolution, 9, p.676682.

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• Ep. 69 - Rewilding Floreana (with Fundación Jocotoco)

  How hard is it to reintroduce species to a tropical island? Turns out, pretty hard! But it’s so worth it. The rewilding of the Galapagos island of Floreana will make it the largest tropical island ever to be rewilded. Researchers have spent over a decade meticulously planning for the reintroduction of the iconic Floreana Giant Tortoise (Chelonoidis niger niger). Once thought to be extinct, this species, along with eleven other locally extinct endemic animal species, are part of a reintroduction project that has involved the massive task of eradication of introduced predators, as well as the purposeful inclusion of the local population throughout the planning process. This month, Bill and Steve are completely out of their depth, discussing the project with three staff members from Fundación Jocotoco, one of the organizations leading the charge to Rewild Floreana.This episode’s special guests are Paola Sangolquí, Jocotoco’s Galapagos Program Marine Coordinator, Julieta Muñoz, Conservation Strategy Manager, and Jajean Rose-Burney, the Director of Jocotoco US.The episode was recorded in New York, NY on September 23, 2024.Episode Notes and LinksVisit Fundación Jocotoco’s Rewilding Floreana website.Here’s where you can donate to support the project. Please contact Jajean at 1 (716) 247-1255 or [email protected] if you have any questions about how to donate.Steve, Daniel, and Bill would like to shout out extra special thanks to our patrons for making this episode a reality!Sponsors and Ways to Support UsGumleaf Boots, USA (free shipping for patrons)Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes!Support us on Patreon!Check out the Field Guides merch at our Teespring store. It’s really a great deal: you get to pay us to turn your body into a billboard for the podcast!Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.Photo CreditFloreana giant tortoise photo © Agustín Molina - https://galapagosconservation.org.uk/floreana-giant-tortoise-reintroduction/Visit thefieldguidespodcast.com for full episode notes, links, and works cited.

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• Ep. 68 - All Hail the King (Salmon)

  This month, Daniel leads the guys into uncharted waters for the podcast…that’s right, it’s our first-ever episode about fish! The Great Lakes salmon fishery is one of the greatest angling spectacles in the US. Large predatory salmon, native to the Pacific Northwest, are stocked in the Great Lakes region to maintain a world class fishery and control invasive baitfish. The undisputed monarch among these stocked species? The appropriately named King Salmon (Oncorhynchus tshawytscha). While they are fished for year-round, the action heats up when mature King Salmon run (well, they swim, but that’s what it’s called) up the creeks and rivers where they were born or stocked each fall. The salmon run attracts anglers from all over the country, fostering a multi-million dollar industry and countless memories. But what is with all the excitement? Why are Pacific salmon even put here? Dare we even ask, should they be here? In this episode, the guys venture to a popular salmon fishing spot near Lake Ontario and reel in the story of one of the most consequential actions in fisheries management history. This episode was record at the Burt Dam Fishermen’s Park in Olcott, NY on October 8, 2024.Episode Notes Daniel mentioned the scientific name and meaning for the Coho Salmon: Oncorhynchus kisutch. But he failed to mention that the Chinook or King Salmon’s scientific name, which is Oncorhynchus tshawytscha. Oncorhynchus as mentioned in the episode from Greek origin, loosely means “hooked snout,” referring to the “kype” these salmon develop. Tshawytscha is derived from a Russian name for the King Salmon, like how kisutch is derived from a Russian name for the Coho Salmon.Chinook Salmon (Oncorhynchus tshawytscha) are also known as King salmon. Chinook and King are used interchangeably in the episode, as Daniel can’t seem to settle on a common name he likes. As mentioned in the episode, “King” comes from the fact that this salmon species is the largest salmon species in the world. Steve asked Daniel what “Chinook” means, and he did not know. After further research, it is found that the word Chinook is derived from the Chinookan people. This includes several groups of indigenous people of the Pacific Northwest, where the Chinook Salmon is native. And what about Coho Salmon? “Cohos” is a word in one of the dialects of the native peoples of the Pacific Northwest with an unknown meaning, possibly the name for the fish itself. Depths of the Great LakesThe books the guys mentioned were Dan Egan’s The Death and Life of the Great Lakes and Margaret Wooster’s Living Waters: Reading the Rivers of the Lower Great Lakes.Visit thefieldguidespodcast.com for full episode notes, links, and works cited.

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• Ep. 67 - Fishers in the Field: A Hike with Fisher Researcher Dr. Scott LaPoint

  If we want to help wildlife, we need to know when and where they’re moving on the landscape. Dr. Scott LaPoint has spent his career researching just that. When our recent episode on fisher cats left us with a lot of questions, we figured who better to help us out than Dr. LaPoint. He was kind enough to join Daniel and Bill for a hike, sharing his expertise and his amazing ability to communicate science with enthusiasm, humor, and clarity. Join the guys for a wide-ranging discussion on fishers, connectivity, and wildlife-human interaction.Visit thefieldguidespodcast.com for full episode notes, links, and works cited.

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