The Field Guides

This episode, we’re stepping back to the golden age of natural history podcasting by resurrecting the format of the classic show Wild Ideas: The Podcast. Joining us on the trail is one of the OG hosts: the man himself, Gordon Maupin. It’s a 3-way team-up where each of us brings a heavy-hitting seasonal mystery to the table.
First, Steve unravels the rule-breaking world of the Ambystoma polyploid salamander complex, where unisexual lineages are mixing up DNA from different species and blurring the lines of what makes a species a species. Then, Gordon shrinks things down to look at the world of duckweed ecology, a group that includes the smallest flowering plants in the world. Finally, Bill turns our eyes to the skies over the marsh to pull back the curtain on dragonfly migration, looking into the recent science that shows some dragonfly species are multi-generational continental travelers (as well as badass predators).
Come listen in as Gordon and the guys answer the question, “What’s going on outside?” (Wild Ideas fans, that’s for you)
This episode was reecorded at the Iroquois National Wildlife Refuge in Alabama, NY on May 13, 2026.
Episode Links
Check out the Iroquois National Wildlife Refige and their Bald Eagle Cam.
Here’s the New York Times article about 7 Podcasts About the Joys of Bird Watching that includes a mention of our show.
Episode Notes
Getting The Great Egret’s Latin Name Right
During a quick aside this episode, Gordon spotted a Great Egret and Steve tried to recall its scientific name, tentatively going with Erodea alba. He wasn't entirely wrong! The correct name is Ardea alba.
While alba means "white," Ardea is Latin for "heron." It also ties back to the ancient myth by everyone’s favorite Roman poet Ovid, who wrote about a bird rising directly from the ashes of the burned city of Ardea.

What’s the Deal With Axolotls?
We wondered if the axolotl is in the same genus as the Jefferson and blue spotted salamander (Ambystoma) and yes they are!
Species: A. mexicanum (Axolotl)
Unlike most members of Ambystomatidae—which typically metamorphose into terrestrial adults—the axolotl exhibits a trait called neoteny (or paedomorphosis). This is where an organism retains juvenile or larval traits into adulthood. Axolotls retains its aquatic, larval features (like its signature feathery external gills) into adulthood and spends its entire life in the water

Bill’s Hard Claim on ID’ing Jefferson Salamanders
Bill said there is no way we could tell if it was a Jefferson salamander: is that true? Bill was basically right if we’re talking about visually confirming a female-looking salamander in a blue-spotted/Jefferson overlap zone. Many unisexual individuals cannot be confidently identified by sight, and genetic testing is the clean answer. But during the breeding season, a male with a swollen cloaca is not part of the all-female unisexual lineage, so that can help narrow things down. So, a male in breeding condition can sometimes be identified much more confidently than a female/unisexual-looking animal, but you need to have serious knowledge about species location, morphology, and breeding-season characteristics.

The Jefferson Complex vs. the Bigger Unisexual Salamander Situation
During the episode, Bill had a “wait, what are we even talking about?” moment while Steve was explaining the huge all-female/unisexual Ambystoma salamander lineage.
Steve was talking about the big-picture version: a bizarre evolutionary group that can involve genomes from several mole salamander species, including Blue-spotted, Jefferson, Small-mouthed, Streamside, and Tiger Salamanders.
Bill, though, was thinking what we hear more about in the Northeast and Great Lakes region: the “Jefferson complex,” or the Blue-spotted/Jefferson Salamander mess. Around here, that usually means you can’t usually ID a Jefferson Salamanders or a Blue-spotted Salamander down to species because the sally in front of you may belong to the all-female, polyploid lineage that can’t be confidently sorted out just by looking at them.
So Bill’s question was basically: “Hold on. Is this identification nightmare only a Jefferson/Blue-spotted thing, or does it happen with the other species too?”
And the answer is: yep. It can happen with the others too.
The narrower Jefferson complex usually refers to the Blue-spotted/Jefferson part of the story, especially in places where those are the main overlapping species. But when scientists zoom out and include the other players (Small-mouthed, Streamside, and Eastern Tiger Salamanders) they usually refer to the whole thing as the unisexual Ambystoma lineage.
So the practical field takeaway is this: in places where these species overlap, a female-looking Ambystoma salamander may be impossible to identify with confidence by appearance alone. Even experts may only be making an educated guess unless they use genetic testing. Measuring red blood cell size can help estimate ploidy (basically, whether the animal has extra chromosome sets) but DNA testing is the real way to know which genomes are actually in there.

Is Duckweed the Smallest Flowering Plant?
Yes, but specifically a microscopic type of it. The world's smallest flowering plants belong to the genus Wolffia - Often referred to as "rootless duckweed" or "watermeal," they are the tiniest members of the duckweed family (Lemnaceae)
Individual Wolffia plants are usually less than 1 mm long, roughly the size of a pinhead or cornmeal, and the flowers are correspondingly microscopic.
Unlike standard duckweed (Lemna), Wolffia plants do not have roots and appear simply as tiny floating green spheres or oval seeds.
The plant produces the world's smallest flower, which forms in a tiny depression on the plant's top surface.
Because they are so small and have highly efficient asexual budding, they can easily cover a pond in dense mats before you ever notice an individual plant. Can be found across temperate and tropical regions of North, Central, and South America

Correction: Ed Yong’s An Immense World (UV, not Infrared)
During the episode, Bill mentioned Ed Yong’s phenomenal book, An Immense World, and noted that researchers are increasingly discovering how many animals can see in the infrared spectrum. His memory slipped slightly on this one! Yong actually discusses the growing scientific realization that many animals see in the ultraviolet (UV) spectrum, not infrared. (Though as you'll see below, dragonflies do have a few tricks up their sleeves on the other end of the spectrum).

Gordon's Question: Infrared Vision & Dragonfly Mating
Bill’s misremembering of what was in An Immense World was prompted by Gordon asking a fantastic question during the recording: Can dragonflies see in the infrared spectrum, and if they can, are they using it to navigate during migration?
First, a quick clarification: when most of us hear “infrared,” we immediately picture thermal imaging — animals glowing in the dark, Predator vision, that whole thing. That is not what we’re talking about here. Dragonflies do not appear to see heat signatures.
What they may be able to see is near-infrared — light just beyond the deepest red wavelengths visible to humans. Near-infrared is not heat vision. It is more like an invisible extension of red.
According to a recent study published in January 2026 by researchers in Osaka, Japan, some dragonfly species have visual pigments that are sensitive to extremely long red wavelengths, possibly reaching into the near-infrared edge of the spectrum. That alone is pretty wild. But the discovery also highlights a striking example of parallel evolution between insects and primates. Millions of years ago, the ancestors of humans and other primates evolved molecular changes that helped produce red-sensitive vision. This new research suggests that some dragonflies may have independently evolved a similar molecular tuning mechanism for detecting red light. However, while primate red vision operates within the visible spectrum, some dragonflies appear to have pushed that sensitivity even farther, toward the boundary between deep red and near-infrared.
So what are they doing with this ability? Probably not navigating migration, at least as far as we know.
The better-supported idea is that this long-wavelength vision helps dragonflies identify mates quickly in flight. Male and female dragonflies can reflect red and near-infrared light differently, especially against green vegetation. So for an animal making split-second decisions while zipping around at high speed, that extra visual contrast could be a big deal.
So to answer Gordon’s question, dragonflies may be seeing farther into the red/near-infrared edge of the spectrum than we can, but based on what researchers currently know, they’re probably using that ability for rapid sex recognition, not long-distance navigation. It’s more of a high-speed dragonfly dating filter than infrared GPS.

The Missing Piece: Visual Cues and "Leading Lines" in Migration
One big element Bill neglected to mention in covering how dragonfies navigate during migration is the VISUAL piece – that they also use what they’re seeing! That is a crucial piece of the puzzle.
Dragonflies are also extremely visual animals. Those huge compound eyes are not just for decoration. So, what they’re seeing is likely a key piece in their migration toolbox.
Migrating dragonflies are often observed moving along major landscape features: coastlines, mountain ridges, river valleys, and other long, continuous edges. Biologists sometimes refer to these kinds of features as leading lines, because they can help guide or funnel migrating animals across the landscape.
That doesn’t mean a dragonfly is looking down and thinking, “Ah yes, the Susquehanna River. I’ll take this south.” But these landscape features can still matter in several ways.
Coastlines can keep migrants from drifting too far over open water, which is risky for an insect that eventually needs to land, rest, and feed.
Mountain ridges and long hillsides can create useful air currents and updrafts, allowing dragonflies to ride favorable winds and conserve energy.
River corridors can provide both a visual pathway and good stopover habitat, with water, vegetation, and plenty of small flying insects to eat when they need to refuel.
The overall migration story for dragonflies probably isn’t “dragonflies have one magic compass.” It’s more like they are combining a bunch of cues at once: the visual structure of the landscape below them, as well as the elements covered during the episode.

Steve's Questions: Resident vs. Migratory Green Darners & The Thermal Genetic Switch
During the episode, Steve asked two really good questions about Common Green Darners: if some are migratory and some are resident, how do they know which group to mate with? And could temperature be the thing that nudges a young darner down one path or the other?
The first answer is surprisingly simple: they probably don’t know, and they probably don’t care.
For a long time, researchers assumed these groups were reproductively isolated, believing residents emerged and died before the migratory cohort reached adulthood, but modern research has overturned this idea. According to a comprehensive review by Michael L. May and John H. Matthews, adult flight periods absolutely overlap in mid-summer, and genetic testing reveals zero genetic differentiation between the groups. The entire continental population belongs to a single, randomly mating gene pool.
So when a Common Green Darner is ready to mate, it is probably not checking whether the other darner is from the “resident” or “migratory” team. It is just mating with another mature Common Green Darner in the same airspace. Very romantic. Very dragonfly.
Steve’s second question gets at something even more interesting: what makes one generation migrate while another stays put?
This is where temperature, day length, and seasonal timing seem to matter a lot. A Green Darner nymph developing in warm water during long summer days may be pushed toward faster development. That can produce adults that emerge, feed heavily, build up energy reserves, and migrate south in late summer or fall.
But if nymphs are developing as temperatures drop and days get shorter, their development can slow down. Instead of rushing to become adults, they may overwinter as aquatic nymphs and emerge the following year. Those individuals can then become part of the resident breeding population in northern ponds.
So Steve’s instinct was basically right: environmental conditions appear to play a huge role in shaping whether a darner develops quickly and migrates, or slows down and overwinters.
The only thing to be careful about is the phrase “genetic switch.” There probably are changes in gene expression involved. Temperature and day length can absolutely affect how insects develop, but in Common Green Darners, we should probably think of it less as a single switch being flipped and more as a whole developmental pathway being shaped by the environment.
The short version: migratory and resident Green Darners are not separate species or rival dragonfly factions. They appear to be part of one big, mixed population whose life cycle can play out in different ways depending on timing, temperature, and local conditions.
Sponsors and Ways to Support Us
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.
Support us on Patreon.
Works Cited
Hallworth, M. T., Marra, P. P., McFarland, K. P., Zahendra, S., & Studds, C. E. (2018). Tracking dragons: stable isotopes reveal the annual cycle of a long-distance migratory insect. Biology Letters, 14(12), 20180741. doi: 10.1098/rsbl.2018.0741.
Hu, G., Lim, K. S., Horvitz, N., Clark, S. J., Reynolds, D. R., Sapir, N., & Chapman, J. W. (2016). Mass seasonal bioflows of high-flying insect migrants. Science, 354(6319), 1584–1587. doi: 10.1126/science.aah4379.
Knight, S. M., Pitman, G. M., Flockhart, D. T. T., & Norris, D. R. (2019). Radio-tracking reveals how wind and temperature influence the pace of daytime insect migration. Biology Letters, 15(6), 20190327. doi: 10.1098/rsbl.2019.0327.
Lancaster, L. T., Dudaniec, R. Y., Chauhan, P., Wellenreuther, M., Svensson, E. I., & Hansson, B. (2016). Gene expression under thermal stress varies across a geographic range expansion front. Molecular Ecology, 25(5), 1141–1156. doi: 10.1111/mec.13548.
May, M. L. (2013). A critical overview of progress in studies of migration of dragonflies (Odonata: Anisoptera), with emphasis on North America. Journal of Insect Conservation, 17(1), 1–15.
May, M. L., & Matthews, J. H. (2008). Migration in Odonata: a case study of Anax junius. In A. Córdoba-Aguilar (Ed.), Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research (pp. 63–77). Oxford University Press.
Sato, R., Terakita, A., & Koyanagi, M. (2026). Dragonfly red opsins share a common tuning mechanism with mammalian red opsins and further enhancement of near-infrared sensitivity. Cellular and Molecular Life Sciences.
Trottier, R. (1971). Effect of Temperature on the Life-Cycle of Anax junius (Odonata: Aeshnidae) in Canada. The Canadian Entomologist, 103(12), 1671–1683.
Wikelski, M., Moskowitz, D., Adelman, J. S., Cochran, J., Wilcove, D. S., & May, M. L. (2006). Simple rules guide dragonfly migration. Biology Letters, 2(3), 325–329.
Yong, E. (2022). An Immense World: How Animal Senses Reveal the Hidden Realms Around Us. Random House.

Every now and then, a conservation opportunity comes along that you can't pass up. The Western NY Land Conservancy (WNYLC) is currently in a race to permanently protect the Bear Lake Preserve, 311 acres of undeveloped shoreline, mature forest, and an array of critical wetland habitats linked to the Lake.
To break down what makes this property so special, the guys hit the trail with WNYLC Stewardship Director Josh Balisteri. He gives them a tour of the property, discussing the history and ecology of Bear Lake, the historical and global crisis of wetland loss, and why we need to start viewing the Great Lakes ecosystem through the lens of crucial "inland coasts."
Head over to wnylc.org/bearlake to check out maps of the new preserve and support their work!
This episode was recorded at Bear Lake in Stockton, NY (and Pomfret, NY) on May 18, 2026.
Episode Notes and Links
Lucy and Bear Lake:
During the episode, Bill boldly threw out a bit of local lore suggesting that WNY’s favorite daughter, Lucille Ball, once stayed at a cottage on Bear Lake. He diligently searched online for any evidence that this was true, but came up empty. Lucy did grow up on the shores of nearby Chautauqua Lake in Celoron and spent many summers during the peak of her popularity escaping to Chenango Lake in eastern NY, but there is no official record of her hiding out at Bear Lake.
Sorting Out Our Flight Paths:
Later in the conversation, Bill referenced Darryl McGrath’s excellent book Flight Paths: A Field Journal of Hope, Heartbreak, and Miracles with New York's Bird People and misidentified Hemlock Lake as one of the state's first eagle hacking (establishment) sites. While Bill was correct in remembering that Hemlock Lake was mentioned in the book, he was confused about the context. In reality, Hemlock Lake played a far more poignant role: it was the home of the very last known native nesting pair of bald eagles in New York State. By the late 1970s, chemical contamination from DDT had devastated the population, and that lonely Hemlock Lake pair was all that remained of our national bird in the entire state. (The pioneering hacking program Bill was thinking of launched nearby at the Montezuma National Wildlife Refuge).
Why the South Shore of Bear Lake Stayed Wild:
A major piece of that puzzle comes down to local history: from the 1920s through the 1970s, the land was home to a vibrant YMCA camp, and local authors Bob and Anne Deming (who Josh mentioned as key people in aiding the effort to save Bear Lake) published a book mapping out the camp’s history. Originally inspired by a single chapter in their debut book, A History of Bear Lake (recently updated and re-released), they dove deeper into the archives to publish Camp in the Woods, a collection of photos and first-hand accounts from nearly 500 former campers and staff members.
Find their books on Amazon: Bob and Anne Deming's Author & Book Page
Read more about the project: New Book Recounts Stories from Y Camp in the Woods
Special thanks to Andrew Gaerte, the Western New York Land Conservancy’s Director of Development and Communications, for sharing this history with us!
Find out more about the Western NY Land Conservancy, including the Bear Lake Project and their Western NY Wildway.
Sponsors and Ways to Support Us
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.
Support us on Patreon.
Works Cited
Peterjohn, W.T. and Correll, D.L., 1984. Nutrient dynamics in an agricultural watershed: the role of a riparian forest. Ecology, 65(5), pp.1466-1475.
Radomski, P. and Goeman, T.J., 2001. Consequences of human lakeshore development on emergent and floating-leaf vegetation abundance. North American Journal of Fisheries Management, 21(1), pp.46-61.
Schindler, D.E., Geib, S.I. and Williams, M.R., 2000. Patterns of fish growth along a gradient of shoreline development. Nature, 407(6801), pp.202-205.
This episode’s photo is from the WNYLC’s Bear Lake Project page!

Something’s not right in the woods, at least if you’re a white-tailed deer. In this episode, the guys dig into chronic wasting disease (CWD), a strange illness reshaping deer populations in many areas of the Lower 48 (and Scandinavia!). It’s not caused by a virus or a bacteria, but it is related to mad cow disease. They break down what it is, how it spreads, what’s happening inside infected animals, and why it’s so dang hard to contain. The deer are not alright… and there’s a reason.
This episode was recorded on April 23, 2026 at Walton Woods Park in Amherst, NY (a suburb of Buffalo).
Episode Notes and Links
· Are there different CWD strains in a single animal? Chronic wasting disease isn’t a single, uniform pathogen. It’s more like a shifting swarm. Infected deer can carry multiple prion “strains” at once, meaning different misfolded shapes of the same protein that behave in slightly different ways. They could spread through the body differently, build up in different tissues, and cause disease at different rates. Lab experiments show this most clearly: when CWD prions are passed through model systems, what looks like one strain can split into multiple distinct variants, or reveal that a mixed population was there all along (e.g., Angers et al. 2010 PNAS; Béringue et al. 2012 Journal of Virology; Li et al. 2010 Journal of Virology). In actual deer, the picture is harder to pin down, but studies comparing prions from different tissues and individuals show real strain diversity and suggest that more than one strain can exist within a single animal (e.g., Angers et al. 2009 Journal of Virology; Moore et al. 2016 Emerging Infectious Diseases). The takeaway is that CWD behaves less like a single disease agent and more like a moving target: a cloud of protein shapes, some dominant, some hidden in the background, that can shift over time, giving the disease more chances to adapt, persist, and potentially jump into new hosts.
· Does repeated exposure to CWD reduce incubation time in deer? Repeated exposure to CWD prions does likely shortens incubation time, mainly because prion diseases are strongly dose-dependent. Higher cumulative exposure, whether from a single large dose or many smaller ones over time, can both increase the chance of infection and accelerate disease progression. Experimental studies in deer and elk show that animals exposed to higher or repeated doses tend to develop symptoms faster than those exposed once at low levels. In the wild, this likely plays out through repeated contact with contaminated environments like soil, plants, and carcass sites. That said, factors like genetics and prion strain can still influence how quickly the disease develops in any given animal.
· Is CWD the only prion disease that affects wildlife? CWD is the only prion disease currently thriving as a self-sustaining epidemic in wild populations. The others mostly sit at the edges and are livestock diseases that occasionally spill into wildlife or appear in captive/wild interface cases. For example, scrapie occasionally “leaks” into the wild (it has been found in bighorn sheep), but it doesn’t take over. It flickers at the edges of livestock systems. Nothing like the landscape-level, self-sustaining spread we see with CWD. That’s what makes CWD so concerning: it’s not just present in wildlife, it seems to be built for it.
· Steve talked about the possibility of vampire bats and wild hogs spreading CWD. What’s the story? There’s currently no evidence that vampire bats are spreading CWD, but the wild hog story has gotten more interesting recently. Blood-feeding bats like the Common Vampire Bat (Desmodus rotundus) are often mentioned because prions can occur in blood at low levels, but there are no peer-reviewed studies showing bat-mediated transmission, nor any field patterns linking bats to CWD spread. So the bat idea remains speculative. Wild hogs (Sus scrofa), on the other hand, have moved beyond pure theory. A recent peer-reviewed study (e.g., Soto et al. 2025 Emerging Infectious Diseases) detected low levels of CWD prion activity in free-ranging pigs in endemic areas, suggesting they can pick up and carry prions after scavenging infected carcasses. Combine this with earlier work showing prions can survive digestion and still remain infectious (e.g., Nichols et al. 2009 PLoS ONE), it all points to hogs as plausible mechanical vectors: in other words, organisms that can move infectious material without necessarily developing the disease themselves. The takeaway: vampire bats are still a biologically interesting but unsupported idea, while wild hogs are emerging as potential “messy middlemen,” capable of redistributing prions across the landscape, even if they’re not a primary engine of CWD transmission, which is still driven by deer-to-deer contact and long-lived environmental contamination.
· Why doesn’t NYS do more free testing?
New York doesn’t offer broad, free testing for every deer. Not because it’s ignoring CWD, but because it uses a more targeted, strategic approach. There are a few key constraints on broad, free testing:
Cost & logistics: Each test isn’t just a swab. It involves lab processing (often PCR or amplification assays), trained staff, and sample handling. Scaling that to hundreds of thousands of deer is a major lift.
Low prevalence (right now): When disease prevalence is near zero, mass testing tends to return very few positives, so agencies prioritize early detection in hotspots instead.
Management strategy: Agencies often invest more in prevention (carcass transport rules, feeding bans, education) than broad surveillance.
Hunter participation: “Free for all” testing can overwhelm systems unless tightly managed, and many states have learned that targeted programs get better data per dollar.
So NYS is focusing its efforts on where they see it mattering most: high-risk areas, roadkills, sick/dead deer, and zones near known outbreaks—because testing every hunter-harvested deer statewide would be extremely expensive for relatively low yield in a state with no established CWD population.
More info on NY’s response, as well as what’s happening nationally:
The NYS Department of Environmental Conservation’s page on CWD (including information on how you can help, scroll down to “Members of the Public”)
CWD in Captive Deer: DEC’s Response in 2024
Chronic Wasting Disease Detection and Management: What Has Worked and What Has Not? A report by the CWD Alliance, a nonprofit organization focused on education, coordination, and outreach around chronic wasting disease. It was created to bring together a mix of stakeholders: state wildlife agencies, federal partners, scientists, and hunting/conservation groups to help share reliable information and improve how CWD is managed across North America.
Sponsors and Ways to Support Us
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.
Support us on Patreon.
Works Cited
Bian, J., et al. (2022). Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of chronic wasting disease. Acta Neuropathologica Communications, 10, 149.
Edmunds, D. R., Kauffman, M. J., Schumaker, B. A., Lindzey, F. G., Cook, W. E., Kreeger, T. J., Grogan, R. G., & Cornish, T. E. (2016). Chronic wasting disease drives population decline of white‑tailed deer. Ecology, 97(3), 620–632.
Henderson, D. M., Denkers, N. D., Hoover, C. E., Garbino, N., Mathiason, C. K., & Hoover, E. A. (2015). Longitudinal Detection of Prion Shedding in Saliva and Urine by Chronic Wasting Disease-Infected Deer by Real-Time Quaking-Induced Conversion. Journal of virology, 89(18), 9338–9347. https://doi.org/10.1128/JVI.01118-15
Küry, S., et al. (2023). The zoonotic potential of chronic wasting disease—A review. Pathogens, 12(3), 342.
Miller, M. W., et al. (2024). U.S. Geological Survey science strategy to address chronic wasting disease. U.S. Geological Survey Circular 1546.
Monello, R. J., Powers, J. G., Hobbs, N. T., Spraker, T. R., O’Rourke, K. I., & Wild, M. A. (2014). Endemic chronic wasting disease causes mule deer population decline in Colorado. PLOS ONE, 9(10), e110353.
Pirisinu, L., et al. (2024). Zoonotic potential of chronic wasting disease after adaptation in sheep. Emerging Infectious Diseases, 30(12).
Sandberg, M. K., et al. (2022). Humanized transgenic mice are resistant to chronic wasting disease prions from reindeer and moose. Journal of Infectious Diseases, 226(5), 933–942.
Saunders, S. E., Bartelt‑Hunt, S. L., & Bartz, J. C. (2012). Occurrence, transmission, and zoonotic potential of chronic wasting disease. Emerging Infectious Diseases, 18(3), 369–376.
Visit thefieldguidespodcast.com for full episode notes, links, and works cited.

The Brown Tree Snake (Boiga irregularis) has wreaked ecological havoc on Guam since its accidental release in the years following WWII, playing a major role in the extinction of endemic bird species and causing trophic cascades that have rewired how the island’s forests function. But how did a population of millions come from just a handful of snakes? And how does this species continue to thrive after eliminating so much of its prey base? A soon-to-be-released study looked into the genome of this invasive species and uncovered some intriguing possibilities. In this episode, the guys welcome their special guest, Dr. Christopher Osborne, to discuss his study and its implications for species management.
This episode was recorded on March 15, 2026 at Rollin T. Grant Gulf Wilderness Park in Lockport, NY, a place Bill has (jokingly) called “the armpit of WNY” despite its deep history and the fact that he’ll absolutely encourage you to check it out.
Episode Notes and Links
In the beginning of the episode, Steve said we would definitely, 100%, without doubt, cover something called Lewontin’s paradox. Well, we skipped it! The main idea behind the paradox is that genetic variation varies little among species, but population size varies massively. We would expect large populations to have a lot of genetic diversity, but we often find that they don’t. Population size doesn’t always scale with genetic diversity.
Sponsors and Ways to Support Us
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for many of our episodes.
Support us on Patreon.
Works Cited
A single preprint!
Osborne, C.A., Foote, B.M., Fleck, S.J., Waterman, H.M., Chang, S.L., Nafus, M.G., Bellinger, M.R., Gray, L.N. and Krabbenhoft, T.J., 2026. Genomic Structural Variation Rescues a Classic Biological Invader from a Population Bottleneck. bioRxiv, pp.2026-01.
https://www.biorxiv.org/content/biorxiv/early/2026/02/02/2026.01.30.702330.full.pdf
Photo Credit
Brown tree snake, USDA/APHIS, Public Domain, https://www.fws.gov/media/brown-tree-snake

It’s gator time, folks! It seems like we should’ve already covered this topic, but, nope, this is our first ever episode on the American Alligator (Alligator mississippiensis), and we’ve got two ringers to help: Daniel returns (our Field Guide host who moved to Florida last year) and he’s joined by his mentor in all things swamp-related, Chip Campbell. Chip spent twenty years running Okefenokee Adventures, leading interpretive tours in the Okefenokee National Wildlife Refuge, and his knowledge of alligator natural history and ecology runs deep.
Thanks to our Patrons, this episode is also an on-the-road joint. The guys are deep in the Florida Everglades on a multi-day paddling trip, and they take a break at camp to talk with Chip about all things alligator — with a special focus on separating gator myths from reality.
And, unfortunately for those of you crushing on Steve, this one’s 100% Steve-free.
This episode was recorded on Dec. 31, 2025 at Watson’s Place campsite in Everglades National Park.
Episode Notes and Links
Alligators, metabolism, and the “dog comparison”
During the episode, Chip mentioned a study suggesting that several alligators could be maintained on roughly the same caloric intake as a single dog. We were not able to locate a study that makes that specific numerical comparison. However, the underlying idea is strongly supported by research on alligator physiology: American alligators have extremely low metabolic rates compared to warm-blooded mammals because they are ectothermic and do not spend energy maintaining body temperature. Classic physiological work shows that adult alligators can have daily energy expenditures that are only a small fraction of those of similarly sized mammals, making informal comparisons like this directionally accurate even if the exact ratio is anecdotal rather than experimental. Source: Coulson, R. A. (1989). Biochemistry and physiology of alligator metabolism in vivo. Integrative and Comparative Biology, 29(3), 921–934. https://doi.org/10.1093/icb/29.3.921
Freshwater “sipping” — the study behind the observation
The behavior Chip describes is documented in a study by Nifong and Lowers, which examined how coastal alligators use estuarine habitats. The authors note that after heavy rainfall, a thin layer of freshwater can temporarily sit on top of saltier water, and alligators will take advantage of this by drinking from the surface. This helps them manage hydration and salt balance in brackish environments, despite lacking the salt-excreting glands found in crocodiles. Source: Nifong, J. C., & Lowers, R. H. (2017). Reciprocal intraguild predation between Alligator mississippiensis and elasmobranchs in the southeastern United States. Southeastern Naturalist, 16(3), 383–396.
Alligator growth vs. age
Chip addressed the myth that alligators continue to grow throughout their life. Echoing what he reported, research on American alligators shows that although hatchlings and juveniles grow rapidly, their rate of growth slows substantially as they get older, and studies indicate they reach near-maximum body size well before the end of their lives. Long-term data suggest many alligators stop adding significant length by roughly 25–35 years of age, and more recent work has revised the classic idea of indefinite growth toward a pattern of determinate growth with a growth plateau in adulthood.
Human harvest of alligators in Louisiana
As Chip said, Louisiana supports the largest wild harvest program for the American alligator in the United States, with more than 2,000 licensed hunters routinely harvesting an estimated 30,000–35,000 wild alligators annually under a regulated tagging system. In contrast, other states such as Florida have had regulated harvest programs with substantially lower annual take.”
Sources: Joanen et al. (2021), Evaluation of Effects of Harvest on Alligator Populations in Louisiana, Journal of Wildlife Management; Louisiana Department of Wildlife and Fisheries Alligator Annual Report (2019–2020); Hines (SEAFWA) status report on Florida alligators.
Fatal Alligator Attacks
In this episode, Chip discusses the history of fatal alligator-human conflicts, highlighting the 1973 Sharon Holmes incident as the first "fully confirmed" fatal attack in modern records. While the Holmes incident is often cited as the definitive first case, there was an earlier death that some consider to be the first modern fatality. Historical records show why Chip’s reference to the Holmes case being the first “fully confirmed” case is accurate:
Sharon Holmes (1973): On August 16, 1973, 16-year-old Sharon Holmes was killed while swimming at Oscar Scherer State Park. This is widely cited as the first fully confirmed fatality because of the absolute nature of the evidence: the attack was witnessed by bystanders, and a subsequent necropsy of the 11-foot 3-inch alligator found conclusive physical remains. This event marked a turning point in how state agencies, like the Florida Fish and Wildlife Conservation Commission (FWC), tracked and verified alligator-related deaths.
Allen Rice (1957): While most official FWC lists of fatal attacks begin in 1973, the 1957 death of 9-year-old Allen Rice in Eau Gallie is often mentioned as an earlier case. However, it is technically categorized as presumed. Rice went missing while fishing, and though his body was recovered with injuries consistent with an alligator and a large gator was seen nearby, there were no direct witnesses to the strike.

Sponsors and Ways to Support Us
Gumleaf Boots, USA (free shipping for patrons)
Thank you to Always Wandering Art (Website and Etsy Shop) for providing the artwork for this and many of our episodes.
Support us on Patreon.
Works Cited
Coulson, R. A. (1989). Biochemistry and physiology of alligator metabolism in vivo. Integrative and Comparative Biology, 29(3), 921–934. https://doi.org/10.1093/icb/29.3.921
James C. Nifong & Russell H. Lowers (2017). Reciprocal Intraguild Predation between American Alligator (Alligator mississippiensis) and Elasmobranchii in the Southeastern United States. Southeastern Naturalist 16(3): 383–396.
Joanen et al. (2021), Evaluation of Effects of Harvest on Alligator Populations in Louisiana, Journal of Wildlife Management; Louisiana Department of Wildlife and Fisheries Alligator Annual Report (2019–2020); Hines (SEAFWA) status report on Florida alligators.
McIlhenny, E.A. (1935) The Alligator's Life History. Boston: The Christopher Publishing House.
Photo Credit
Thanks again Always Wandering Art (Website and Etsy Shop) for the amazing gator painting!