• Aba aba Fish
    Jul 2 2025
    Summary: What’s an Aba aba? It’s our next unknown creature! Join Kiersten as she introduces us to the Aba aba fish. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Gymnarchus niloticus” Global Biodiversity Information Facility, https://www.gbif.org “Gymnarchus niloticus, Aba aba” Seriously Fish, https://www.seriouslyfish.com “Morphology of Aba Knife Fish (Gymnarchus niloticus) (Cuvier, 1829)”, by S.O. Ayoola and C. E. Abotti. World Journal of Fish and Marine Sciences 2 (5): 354-356, 2010. Music written and performed by Katherine Camp Aba aba Fish Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Kiersten - Welcome to Ten Things I Like About… This is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. My name is Kiersten and I have a Master’s Degree in Animal Behavior and did my thesis on the breeding behavior of the Tri-colored bat. I was a zookeeper for many years and have worked with all sorts of animals from Aba Aba fish to tigers to ravens to domesticated dogs and so many more in between. Many of those years were spent in education programs and the most important lesson I learned was that the more information someone has about a particular animal the less they fear them. The less they fear them the more they crave information about them and before you know it you’ve become an advocate for that misunderstood animal. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. Welcome back, listeners! In this new series after summer break, we will be heading back into the water. Don’t worry we will not need a bigger boat! Okay, I had to throw in a reference to Jaws, being that it’s fifty years old this year, and also one of the reasons that an entire generation of people fear sharks. But that is another series all together. This episode is the first in a new series about a fish. The Aba aba fish to be specific. Never heard of it? That’s exactly why I picked it as my next unknown creature. This first thing I like about the Aba aba fish, is the Aba aka fish. We will start off this series with an overview of this wicked cool fish to whet your appetite to learn more. The Aba aba fish, Gymnarchus niloticus, is also known as the African knife fish, Frankish, freshwater rat-tail, or aba fish. It is a long, slender bodied fish with only one fin. The dorsal fin runs from the back of the head to the tip of the tail on the top-side of the body. This is their only fin and the reason they are called knife fish because they kinda look like a knife if you used the head as the handle. Aba aba are typically black to gray to brown on the top half of the body while the underside is a paler color, such as white or beige. They are covered in very small scales that do not stand out making it look like they have smooth skin. Adults can reach a length of five feet or 1.6 meters and weight 42 pounds or 19 kilograms. That’s a pretty big freshwater fish. Classification of the Aba aba is as follows- Kingdom: Animalia Phylum: Chordata Class: Actinopterygii (the ray-finned fish. These are fish that have lightly built fins made of webbings of skin supported by thin bony spines) Order: Osteoglossiformes (this is an order of ray-finned fish known as the bony tongue fish and we will delve into to this in more detail in a future episode) Family: Gymnarchidae Genus: Gymnarchus (meaning naked bum) Species: niloticus (meaning from the River Nile) They are the only fish in the family Gymnarchidae and in the Genus Gymnarchus which makes them special. In the wild the Aba aba is found in the freshwaters of Africa. They live n the lakes and rivers of the Nile, Turkana, Chad, Niger, Volta, Senegal, and Gambia basins. This fish is an obligate air breather which means they need to gulp air form the surface of the water to supplement the oxygen that they get from the water. If they cannot do this, they will suffocate. There are other species of fish that are also obligate air breathers. Typically this adaptation is found in fish that live in waters that are thick with sediment or have seasonal changes that can increase the sediments levels in the water. Gulping air gives the fish a clean source of oxygen. Aba aba are predators hunting for other small fish, crustaceans, aquatic insects, copepods, frogs, and snails. The diet is dictated by the size of the Aba aba but they are carnivores throughout their entire lives. This amazingly cool fish is nocturnal and because they are most active at night they have an adaptation that makes them even cooler. No way, you say! How could they get any...
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    9 mins
  • Screamers: Conservation
    May 14 2025
    Summary: Are Screamers in need of conservation? Join Kiersten to find out! For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: Screamers: https://animaldiversity.org Data Zone by Bird Life: https://datazone.birdlife.org IUCN Red List: https://www.iucnredlist.org American Bird Conservancy: https://abcbirds.org/bird/southern-screamer/ Asociacion Armonia: https://armoniabolivia.org Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. This is the final episode of Screamers and we’ll be talking about conservation. Like everything else with Screamers this episode will have a few twists. The tenth thing I like about Screamers is conservation. Each species has a story of it’s own, so we’ll take them one by one. Let’s start off with the Southern Screamer. Southern Screamer, Chauna torquata, also known as the Crested Screamer is found from the eastern half of Bolivia south into Argentina as far as Buenos Ares Province and east through Paraguay into south western Brazil and Uruguay. The conservation status of the Southern Screamer is listed by the International Union for Conservation of Nature and Natural Resources as Least Concern. This means that Southern Screamer population numbers are steady or increasing. Their population trend is listed as stable with adult individuals estimated between 66,700 to 667,000 individuals. The last time this species was assessed was in 2024. This species of Screamer is impacted by habitat loss. As wild lands are drained and deforested to create more land for cattle ranching and farming, Southern Screamers lose vital habitat, but a 27,000 acre reserve created in 2008 by Asociacion Armonia to protect the Blue-throated Macaw had the added bonus of offering protected habitat to the Southern Screamer. Barba Azul Nature Reserve protects 250 species of birds and is an important stop over for migratory shorebirds. If you are interested in seeing the Southern Screamer at the reserve you can book a conservation birding trip through American Bird Conservancy. All fees support the reserve and American Bird Conservancy’s mission for protecting wild spaces for birds. Now there are other things keeping the Southern Screamer protected, this is the twist for this species, ranchers and farmers actually like having Southern Screamer nearby as they are excellent guard birds and raise the alarm when any predators come near. Sometimes people sneak a young Screamer away from the parents and keep them on their property for exactly that reason. Southern Screamers have also been seen eating invasive plants species, such as white clover, which means they are helping their own conservation efforts. The Northern Screamer, Chauna chavaria, also known as the Black-necked Screamer is in a similar situation as the Southern Screamer. This Screamer is found across northern Columbia from the Atrato River and Magdalena River valleys east into the Lake Maracaibo area of Venezuela. They are also under pressure from habitat destruction for ranching and agricultural use. As of the latest surveys in 2023, the Northern Screamer is listed as Least Concern by the IUCN. Their population is stable with 60,000 to 130,000 mature adults. Locally, in Columbia and Venezuela, they are listed as Vulnerable. Conservation efforts in these countries include educational campaigns bringing awareness to Northern Screamers and their importance in the local environment. Several preserves have also been established to help protect the wetland areas that these birds rely upon. Other threats to the Northern Screamer include egg collection by humans for use as food and collection of young for the local pet trade. The last species of Screamer, the Horned Screamer, Anhima cornuta, is found in the Amazonian regions of Venezuela, to the eastern llanos of Columbia, to eastern Bolivia and south-central Brazil. Their latest assessment by the IUCN was in July of 2024 and they are currently listed as Least Concern with a stable mature adult population estimated between 16,700 to 66,700. There are not many conservation efforts in the region specifically aimed at the Horned Screamer, but there are established conservation sites throughout their range to prevent more wetlands from being drained for ranching needs. The subcutaneous air sacs found in all three species of Screamer keep these birds ...
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    8 mins
  • Screamers: Eyes and Beak
    May 7 2025
    Summary: Join Kiersten as she talks about the eyes and beaks of the Screamer. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: Ornithology 3rd Edition by Frank B. Gill “The evolutionary relationship among beak shape, mechanical advantage, and feeding ecology in modern birds,” by Guillermo Naval, Jen A. Bright, Jesus Marugan-Lobon, and Emily J. Rayfield. Evolution 73-3;422-435, Society for the Study of Evolution. doi:10.1111/evo.13655 “Bird Eye Color: A Rainbow of Variation, a Spectrum of Explanations,” by Eamon C. Corbett, Robb T. Brumfield, and Brant C. Faircloth. Https://doi.org/10.1111/ibi.13276. Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. This is the penultimate episode of Screamer and the ninth thing I like about this animal is their eyes and beaks. One of the things that is often overlooked in bird is their eye color, so today we will delve into the variations that exist by looking through the eye of the Screamer. Bird beaks, or bills either is correct, also vary extensively through out the avian family. Beak shape often indicates what type of food the birds eats, but like everything else about the Screamer, things are not always as they seem. Bird eye color varies more than anyone expected. Not many researchers have attempted studying this characteristic and the few that have taken up this research topic and finding more questions than answers. Colors ranged form dark black or brown to vivd emerald green, sapphire blue, scarlet and crimson, turquoise, and even white. There is even a bird with pink eyes. It is absolutely amazing the various hues that birds’ eyes contain. Irises can be one color or more than one. The eyes of Rock Pigeons, one of the most disliked birds around the world, are bicolored starting with a ring of yellow on the outside and red/orange close to the pupil. The Satin Bowerbird has eyes with a vibrant blue ring on the edge of eye with an equally vibrant ring of purple next to the pupil. The Three-streaked Tcharga has a ring of light spots that look like stars set in a dark background giving them some of the most unique bird eyes around. Eye color in birds can change as a bird matures, for example Osprey eye color changes from red as juveniles to yellow as adults. Sexual dimorphism is also present in some species of birds meaning the female’s eyes are a different color than the male’s. Seasonal changes in eye color can also happen, for example Brown Pelican eyes change from brown to blue during breeding season. Southern Screamers and Northern Screamers both have brown eyes as adults, while Horned Screamers can have yellow to orange to red eyes as adults. To clarify, I found no research indicating that these birds eye color changes as they age, but I could only find reference to their adult eye color. There are three things that contribute to the color of a bird’s eye, pigments, blood vessels, and structures. These three color options are still being closely studied but certain pigments are responsible for light colors and different pigments are responsible for darker colors. For example, carotenoids are responsible for the orange color of birds in Family Anatidae which includes certain ducks. An increased amount of blood vessels in the eye creates the red eyes of some species. Why do bird have such varied eye color? The short answer is we just don’t know. It could be related to how they find food, where they nest, diurnal versus nocturnal behaviors, communication, or another reason we have not thought of yet. Much more research needs to be done to answer this question, but for now, we can marvel at the extreme variation of bird eye color. Now, let’s take a look at some bird beaks. Just like eye color bird beaks vary tremendously. They can be wide and flat like a duck, tweezer-like similar to a gnatcatcher, chisel-like as the raven’s beak, long and thin like a hummingbirds, and deeply curved like the honeycreeper. These are only a few beak shapes found in the avian world. What a bird eats can impact the shape of its beak. Keeping this idea in mind, let’s look at the Screamer’s beak. Screamers eat leaves, stems, flowers, and roots of aquatic vegetation, so we might assume that their beaks would look at lot like their closer relatives ducks, geese, and swans who also eat similar items. Duck ...
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    9 mins
  • Screamers: Vocalizations
    Apr 30 2025
    Summary: Do Screamers actually scream? Find out in this episode of Ten Things I Like About Screamers. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Observations on the Horned Screamer,” by Frank B. Gill, F.J. Stokes, and C.C. Stokes. Wilson Bulletin, Vol. 86 (1974), Iss. 1, Art. 6. https://digitalcommons.usf.edu/wilson_bulletin/vol86/iss1/6 Screamer Vocalizations: https://birdsoftheworld.org/bow/species/horscr1/cur/sounds Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. Listeners, let me first apologize for missing a week in the middle of Screamers. Spring has started off extremely busy for me and time got away from me. Let’s jump back in with episode eight of Screamers. The eighth thing I like about Screamers is their vocalizations. Yes, that’s right we are finally going to talk about the attribute that gives these birds their common name, Screamers. Most of the research I found on the vocalizations of Screamers focused on the Horned Screamer, Anhima cornuta, so what we talk about today pertains to this species. All species of Screamers make similar calls and vocalizations that’s where the name come from, but the specific details in this episode are about the Horned Screamer. Most of what we know about Horned Screamer vocalization and related behaviors come from the research of Frank B. Gill. Three vocalizations have been observed and described from observations of wild Horned Screamers. I promise you that none of them are a melodious song that you associate with songbirds. Their calls are definitely more like their close relatives swans, ducks, and geese. I cannot play any of these calls for you in this episode due to copyright agreements, but I will post links in the show notes that you can follow to listen to these calls. The first call that we’ll talk about what is titled the Moo Co call. M-O-O C-O is the spelling. This call is bisyllabic meaning it has two notes. The second note has a distinctly lower frequency than the first note. The intensity of this call varies from a melodious call to a harsh bark to a coughing note. The volume of this call can vary from soft and only heard when close to the bird or very loud and can be heard from over a mile away. That’s quite a call! The Moo Co calls are often given by couples in a duetting sequence. When this happens the birds combine their calls by overlapping the second note of the first individual with the first syllable of the second individual. This can result in a trisyllabic call Ha Moo Co or Ha Moo-o Co. This call is where the local name for Horned Screamers, jamuco, comes from. This triple call is only performed by couples, most likely mated pairs, as it was never heard from a single, lonely individual. The triple Moo Co call is the call that mated pairs use to reinforce their bond through the year and at the beginning of each breeding season. It is believed that males produce a louder and deeper pitched Moo Co call than females which makes the duetting a bit more musical. It can also aide in identifying sexes through vocalizations. Moo Co calls are used for alarm calls, distance calls, and greetings. The second call is called honking as it closely resembles the honking calls of a goose. This call consists of two distinct patterns given in various combinations. One of the patterns has seven to eight strongly developed harmonics. This sequence typical lasts about 30 seconds and is often accompanied by head and neck bobbing, especially when multiple screamers are together. Honking is typically used for distance calling and greetings. The third call is a loud bugle-like call titled the Trumpet call. This call consists of two syllables with a low introductory note and a second inflected note. This one is meant for long distance communication as is it the loudest of all three vocalizations. With these three call descriptions, we can clearly see why these birds are called Screamers, when you listen to these calls it will reinforce this name. These birds do a lot of screaming! I do have to admit that the duetting between two Screamers is quite hypnotic and has a lovely sound. I can see why they reestablish their bonds and their territories using this call. In the wild, screamers typically do most of their vocalizing in the early morning, but will call sporadically throughout the ...
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    10 mins
  • Screamers: More Anatomical Anomalies
    Apr 16 2025
    Summary: You mean Screamers have even more physical oddities? Yep! Join Kiersten to find out about more anatomical anomalies of Screamers. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: Ornithology 3rd Edition by Frank B. Gill “A peculiar association: the skin and the subcutaneous diverticula of the Southern Screamer (Chauna torquata, Anserifomes), by Mariana B. J. Picasso, Maria Clelia Mosto, Romina Tozzi, Federico J. Degrange, and Claudio G. Barbeito. Vertebrate Zoology, 64(2): 245-249, 7/25/2014. “A Study of the Pterylosis and Pneumaticity of the Screamer,” by Ida S. DeMay. The Condor, March 1940, vol 42. Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. In this episode we will continue with our anatomical anomalies. The seventh thing I like about Screamers is their unusual feather pattern and subcutaneous air pockets. That is not a sentence I ever thought I would say, but I have had this experience many times since I’ve started Ten Things I Like About… Just like the last episode, we will have to do a little bit of background on avian anatomy before we jump into the Screamer anomalies, so let’s get started. Birds are covered in feathers. When talking about nature you should not use all or never because there is always an exception to the rule, but we can safely say that all birds have feathers. Feathers help bird do lots of different things such as keep warm, keep cool, keep hidden, or advertise their presence, and of course fly. They have different types of feathers that cover their body, such as flight feathers, both primary and secondary that help them fly, tail feathers that help them during flight and balance while perching, downy feathers that lay close to the skin to help with temperature regulation, and bristles that are often seen near the eye or mouth. Feathers grow out of the skin from pores. They are not spread along the entire skin like the fur of most mammals. Avian feathers grow in tracts on the birds body. The concentration of the tracts can differ depending on the species of bird, for example, Tundra Swans, which have approximately 25,000 feathers, have 80% of those feathers on their head and neck, where as, songbirds have 2000 to 4000 feathers and only 30 to 40% are found on the head and neck. In between these track are patches of bare skin called apteria. There are nine major feather tracts. These names of the feather tract are not important for our purposes, but where they are located is pertinent. On most birds the feather tracts travel from the middle of the head at the base of the beak down the spine to the tail. There are more tracts on the tops of the wings from shoulder to wrist, along the side of the neck and belly, and long the legs. You may be thinking, “I have never seen big ‘ole bald spots on birds?” Well the feathers in the tracts lay flat and cover the apteria. That’s why we don’t see them. For any one you that have pet birds that you can handle and groom, know just what I’m talking about. Okay, what does this have to do with our Screamers? Well, Screamer feathers do not grow in tracts like other birds. They grow all over their body. Screamers have no apteria, no patches of bare skin. Why? We don’t know. The other bird species that have this type of feather growth pattern are the flightless ratites including ostriches, emus, rheas, and cassowaries, as well as penguins, so what the flighted Screamers are doing with this pattern of feather growth, we’re not entirely sure. But it is one more thing that makes Screamers unique. The second anatomical anomaly of Screamers that we are going to talk about in this episode is the odd subcutaneous air bubbles they possess. That is right, I said subcutaneous air bubbles. This is pretty odd, let’s delve into it. First a bit of background into bird respiration. Birds do have lungs similar in structure to mammals but they function differently. Most bird species have two lungs attached to the trachea via two bronchi. Sounds pretty familiar, but the air flow is different. In mammals air flow is both in and out. Birds breathe in only one direction, but they have only one trachea. So how does this work? Air sacs that are part of their respiratory system. These sacs allow birds to utilize all the oxygen in each breath and disperse carbon dioxide back into...
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    10 mins
  • Screamers: Skeletal Anomalies
    Apr 9 2025
    Summary: Can Screamers get any stranger? You bet! Join Kiersten as she discusses some skeletal anomalies that Screamers possess. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Functional significance of the uncinate processes in birds”, by Pete G. Tickle, A. Roland Ennos, Laua E. Lennox, Steven F. Perry, and Jonathan R. Codd. The Journal of Experimental Biology 210, 3955-3961. 2007 doi:10.1242/jeb.008953 “Uncinate processes in birds: Morphology, physiology and function,” by Jonathan R. Codd. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology, Vol 156, Issue 3, July 2010, 303-308. Britannica: Screamers, https://www.britannica.com Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. Episode six of Screamers is going to take us on an interesting journey into Screamer anatomy because the sixth thing I like about screamers is their weird anatomical quirks. Last episode we talked about one of their special anatomical accessories, the spurs. In this episode we will look at two more of the Screamer’s anatomical anomalies that also pertain to the skeleton. Many of you have probably heard somewhere that birds have hollow bones. This is a simplified statement about bird bone anatomy. We will need to understand this a bit before we talk about screamer bones, so, those of you that already know this, bear with me, for those of you who are hearing this for the first time, hold on to your hat, I’m about to blow you mind. Vertebrate skeletons are made up of hard, calcium rich bones. It’s what give our bodies their shape and ability to move. Birds are vertebrates so they rely on their skeleton to give their body shape and act as the anchor for muscles to allow them movement, just like mammals. Avian bones are special because they have adapted to the bird’s need to fly. If you have too much weight defying gravity can be difficult. Flighted birds adapted to this challenge by evolving less solid bones than mammals. Using the word hollow, makes you think of a tube, such as a straw or toilet paper tube that is completely open inside with no internal structure. You can look through one end and see clearly out the other end with no obstacles. Bird bones are not hollow in this manner. Their bones have an internal structure throughout the tube. If we were to look inside a bird’s bone we would see more of a honeycomb design. It’s essentially bones with air pockets. These are called pneumatic bones. The bones have lessened weight by getting rid of dense material but have increased strength by adding structure throughout the middle of the bone. This is how flighted birds can get off the ground and fly. They have bones that contain more air that provide structure for the body and muscles without being so solid that flying is a struggle. Now having said this, if we look at an average flighted bird, say a Bald Eagle or a Northern Cardinal, not all of their bones have this honeycomb structure. Typically, the larger bones will have this structure and smaller bones will not. The smaller bones will be more solid. This is where the Screamer skeletal oddity applies. All the bones in a screamer have this open honeycomb structure. All of them, including the smallest toe bone. Screamers have the most pneumatic skeleton of any living bird. And we have no idea why. Screamers are good flyers. Once they get up into the air, they soar like vultures, riding the thermals. They can soar for hours at a time, but as we know they spend most of their time on the ground in or around water. They are a larger bird, so maybe this has to do with their interesting bone structure. On the other hand, geese and swans are the same size, are great flyers and spend most of their time on or near the water, but they do not have this skeletal anomaly. This is not the only abnormality about the Screamer skeleton. Another oddity sets Screamers apart from almost all other birds. This interesting tidbit involves the uncinate processes. As before, we need to do a short anatomy lesson to fully understand the anatomical oddity of the Screamer. The uncinate process is a bony projection that is attached to vertebral ribs in avian skeletons. These projections are important in avian respiration. Birds do not have a muscular diaphragm like mammals to help them inflate ...
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    10 mins
  • Screamers: Spurs
    Apr 3 2025
    Summary: What is it with those spurs? Join Kiersten as she takes a closer look at Screamer spurs. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “On the Spurs On Birds’ Wings,” by R. L. Rand. The Wilson Bulletin, June 1954, Vol. 66, No. 2. Birds of the World: https://birdsoftheworld.org Screamers: https://animaldiversity.org Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. The fifth episode of Screamers is the beginning of a few focused on anatomy. We will start off with the fifth thing I like about Screamers, their spurs. The spurs on the wings of these birds certainly set them apart from their closest relatives; ducks, geese, and swans. These little anatomical gems have been fascinating ornithologists for years. I found a paper published in 1954 in the Wilson Bulletin titled “On the Spurs of Birds’ Wings.” The author, A.L. Rand, describes the spurs of all the Screamers in decent detail. Rand used specimens at the Chicago Natural History Museum for his study. What he found, I have to admit, was quite fascinating and for a paper written in 1954, it was fairly easy to read and understand. I’ve read a lot of scientific papers in my day and this one was a delight. The close up inspection that Rand gave the three Screamer species revealed some interesting details. Let’s talk about these details. All species of Screamer have two spurs. These spurs are attached to the metacarpals of the wing, as we have established in past episodes. The first spur, the larger one, is located on the process of metacarpal 1. The process on this metacarpal is used for attachment of the extensor muscles. The second spur is on the distal end of metacarpal 2. These spurs are described by Rand as follows, “conspicuous, stout, smoothly tapering, sharp spurs with a slight radial curve.” End quote. The spurs are found on both wings, so Screamers have four spurs. The spurs are made up of a horny material on top of a bone center. The horny material is keratin. Upon close inspection, the spurs of the Screamers showed fine lines around the base of the spurs indicating growth in layers. One specimen had three separate bands which may indicate annual growth. At one time is was thought that the spur could be used to determine age of the bird through an annual molt, but there isn’t any evidence that this holds true. Next, let’s look at each species spurs a bit closer. The following numbers are based on the specimens that Rand looked at in the Chicago Natural History Museum, but on average they seem to hold up over time. Anhima cornuta, the Horned Screamer, spur is triangular in cross section. The spur curves toward the body. All the corners are sharp including the tip. The length of the first spur on the male is 58-61mm and the second spur is 15-16mm. Female spurs are smaller with a length of 50-55mm for the first spur and 11-17mm for the second spur. Chauna torquata, the Southern Screamer, spur is nearly oval in cross section but has a sharp-edged flange near the proximal edge resembling the triangular spur of the Horned Screamer. The length of the male’s first spur is 30-47mm while the second spur is 13-20mm. The female’s first spur is 35-45mm and the second is 15-17mm. Chauna chavaria, the Northern Screamer, spur is smoothly oval in cross-section and is sharp only at the tip. The male’s first spur is 28mm and the second super measures 18mm. The female’s first spur is 30mm and the second spur is 18mm. Typically the male’s spurs are longer than females, even though this last example shows the opposite, we have to remember that Rand was looking at only a few specimens at one museum for this paper. Current research indicates that Screamers develop the outer portion of the spur at one year of age. Fledglings do not have the outer protrusion of the spur. So what do they use this spur for? The fact that they don’t develop them until they are on their own indicates that they use them for protection or defense. Screamers have been seen in the wild using the spurs during ma ting season to win the right to court a female. Couples are also fiercely defensive of their nests and have been seen using the spurs as weapons against intruders, both intraspecies, other Screamers, and interspecies, anything else dumb enough to come near a Screamers nest. So, how ...
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    11 mins
  • Screamers: Social Structure
    Mar 26 2025
    Summary: Do Screamers hang out with other Screamers? That depend on the specs. Join Kiersten to find out a little about the social structure of each species of Screamer. For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean Show Notes: “Aspects of the Biology of the Horned Screamer in Southwestern Colombia,” by Luis G. Naranjo. The Wilson Bulletin, Vol. 98, No. 2 (June, 1986, pp. 243-256 “Mortality of four captive-born crested screamer chicks (Chauan torquata)”, by Lana Fox, Alexis Moreno, and Gregory Bradley. Open Veterinary Journal, 2019 Apr 28:;9(2):120-125. Doi:10.4314/ovj.v9i2.5 Screamers: https://animaldiversity.org Music written and performed by Katherine Camp Transcript (Piano music plays) Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife. (Piano music stops) Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it. This is episode four of screamers and the fourth thing I like about Screamers is their social structure. As we have learned previously, there are three species of screamers. Each species is found in a different range of South America, but they reside in similar habitats and eat similar diets. Their coloration is slightly different which does help in identification once you have those differences memorized. Interestingly these three species that are alike is so many ways have different social structures. Let’s start off with the Northern Screamer, also known as the Black-necked Screamer, Chauna chavaria, This screamer is found across northern Columbia from the Atrato River and Magdalena River valleys east into the Lake Maracaibo area of Venezuela. They are most often found near water in habitats such as swamps, marshes, lagoons, riverbanks, and seasonally flooded river plains. They are a non-migratory species, so remain in the same area year round. The social structure of the Northern Screamer seems to revolve around the mated pair. Once a pair bond is established, that couple remains together and defends a territory year around. The pair mates for life or an extended period of time. Since they are a bit anti-social when it comes to entertaining other Northern Screamer neighbors, their social structure is fairly simple. They live in small familial groups consisting of the mated pair and their offspring. I found very few research papers doing in-depth studies into this species social structure but based on other species that remain in familial groups, once the offspring are old enough to reproduce they leave the parents’ territory to find their own mate and establish their own territory, or are run off by the parents to find their own mate and establish their own territory. An educated guess dictates that this is the behavior the Northern Screamers follow, as well. To remain genetically diverse and produce healthy offspring, you gotta leave home. Let’s travel south and visit with the Southern Screamer, also known as the Crested Screamer, Chauna torquata. They are found from the eastern half of Bolivia south into Argentina as far as Buenos Ares Province and east through Paraguay into south western Brazil and Uruguay. Southern Screamers prefer tropical and subtropical wetlands including lakes, marshes, and flooded meadows with scattered trees. They are permanent residents wherever they are found. The social structure of the Southern Screamer varies depending on the season. During breeding season, mated pairs are extremely territorial and will defend their established area fiercelyincluding using the spurs on their wings to fight off intruding screamers or other animals. In the off season, Southern Screamers are the most gregarious of all the screamer species. They gather together in groups of up to 1500 individuals. This species seems to have the closest relationship to humans. These large groups are often seen foraging near livestock. This may have something to do with them gathering in larger groups. It may be a safety in numbers situation, or it could simply be an abundance of resources available in their region. Whatever the reason, the Southern Screamer is definitely the most gregarious screamer of all three species. The third species of screamer is the Horned Screamer, Anhima cornuta. The range of the Horned Screamer is much larger than our other two species and includes the Amazonian regions of Venezuela, to the eastern llanos of Columbia, to eastern Bolivia and south-central Brazil. Habitat frequented by these birds include tropical lowland freshwater areas such as lakes, ponds, ...
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    8 mins