Ten Things I Like About... Podcast

Aba Aba: Osteoglossiformes

Summary: Join Kiersten as she discusses the classification of the Aba aba a bit more closely to find out what it can tell us about this amazing fish.
 
For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean
 
Show Notes: 
“Introduction to the Actinopterygii” https://ucmp.berkeley.edu
Bony Tongue, EBSCO Research Starters: https://www.ebsco.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)
 
Kiersten - 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 episode four, we're going to jump back a bit to episode one and delve into more detail about about the class, order, and family of the Aba aba. The fourth thing I like about Aba abas is their classification. In episode one I briefly described the classification of this fish, but I think we should investigate the class, order, and family of Aba abas a bit more closely.
First for my first time listeners, or for those who are not students of biology, what is classification?  It a system that scientists and researchers use to connect all living things but to also individualize all living things. Whether flora (plants) or fauna (animals) we are all related through physical characteristics. 
Way back in the day, like way back in the 1700s, Carl Linnaeus was a Swedish biologist and physician who developed a binomial nomenclature (a two part name) to organize every living thing into groups. It helped man understand the natural world around him. We still use this classification system today, even though the attributes we use to organize individual plants and animals into their groups has evolved over the years. In the beginning, naturalist used things like appearance and behavior to place animals and plants into the same groups, but now we look at genetic similarities to classify living things.
The two part name consists of the genus and the species. This helps make sure that when you are talking about an individual animal or plant with another researcher you are talking about the same plant or animal. Animals often have different common names around the world and even have different names within the same country. For example, fireflies are known as fireflies, lightening bugs, and glow-worms. These common names vary depending on what region of the United States you may be visiting, but we’re all talking about the same insect. The Aba aba is known as Aba aba, African knife fish, Frankish, freshwater rat-tail, or aba fish, so researchers refer to it as Gymnarchus niloticus. 
If we take a few steps back in the classification we can learn even more about an animal. So let’s do that now with Gymnarchus niloticus. When we look at the Class level of this animal, Actinopterygii, we know that it is a ray-finned fish. What exactly does that tell us? Well, Actinopterygii are fish that possess fins that are made of webs of skin supported by bony or horny spines. We also know that fish in this Class usually have complex skeletons of true bone. Ray-finned fish are the dominant aquatic vertebrates in the water today. They make up about half of all vertebrate species known and are found in every aquatic habitat from the deepest depths of the ocean to freshwater streams and ponds. 
So this level of classification lets us know that Aba abas have a bony skeleton and some sort of webbed fin on their body. It’s a great start. The next step is the Order. This will narrow down things ever more. Aba abas are classified in Order Osteoglossiformes. In Ancient Greek this literally means ‘bony tongue’. Members of this Order have toothed to bony-tongues. They are also known for the forward part of their gastrointestinal tract passing to the left of the esophagus and stomach (in all other fish it passes to the right). They can vary in size ranging from 2 centimeters up to 8 feet or 2.5 meters. 
Up to the early 2000s we thought that Osteoglossiformes were fresh water fish only. All of the 245 known living species of bony-tongued fish are found in freshwater. In 2008 several marine bony tongued fish fossils were discovered in the Danish Eocene Fur Formation. Maybe there are some extant marine osteoglossiformes in the ocean we haven’t found yet. I guess we’ll have to wait and see!
Okay, back to the Aba aba. What does bony-tongued mean in relation to our fish? Bony tongued fish have teeth on their tongues. When they catch prey they use their toothy tongues to crush the prey items against the teeth on the roof of their mouths! Yikes! It sound so cool and so very scary. 
The next step to Gymnarchus niloticus, is the Family, Family Gymnarchidae. The Aba aba is the only fish in this family which it makes it unique, but we already knew that!
I know that scientific classification can be a confusing subject, but I hope this episode helped you understand the Aba aba a bit more. The classification of animals can be very helpful and enlightening and the class, order, and family is my fourth favorite thing about the Aba aba.
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about the Aba aba.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Aba aba: Reproduction

Summary: How do Aba aba make more Aba aba? Join Kiersten to find out about the reproductive behavior of Gymnarchus niloticus.
 
For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean
 
Show Notes: 
“Abundance, Distribution, Morphometric, Feeding Evaluation and the Reproductive Strategies of Gymnarchus niloticus in the Lower River Niger at Agenebode, Edo State Nigeria,” by Mo Agbugui, Fe Abhulimen, and Ao Adeniyi. J. Apple. Sci. Environ. Manage Vol. 25 (8). 1371-1377, August 2021.
“Gymnarchus niloticus Cuvier, 1829
“Some Ecological Factors of the Tropical Floodplain Influencing the Breeding and Conservation of Gymnarchus niloticus (Cuvier 1829): A Review,” by Oladosu O. O., Oladosu G. A. And Hart A. I.
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)
 
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. 
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 three of Aba aba is here and we are talking about reproduction. The end of episode two hinted at reproduction kicking off with the rainy season so that’s where we’ll begin. Join me for the third thing I like about Aba abas, reproduction.
It all begins when two Aba aba love each other, no really, it all begins with the rainy season. In the continent of Africa many animals rely on the abundance of the rainy season. This season brings rain that is a necessary resource for survival of all living things, as well as flooding the rivers. Flooded rivers overflow into flood plains where food becomes abundant. Terrestrial invertebrates are often caught off guard and drown leaving them to be consumed by aquatic carnivores, like the Aba aba. The Aba aba already lives in the water but when those waters rise nutrients increase and aquatic vegetation gets thicker. Then it’s time to start looking for a mate.
In studies performed in the Lower River Niger, two breeding peaks were observed. One from May to July, the other from October to January. The breeding behavior of Gymnarchus niloticus is heavily dependent on the flooding of the rivers. Beyond the food resources that increase at this time the aquatic plants that increase are important for the nest making of the Aba aba.
Now, the males of the species are the ones that make the nests. This is not uncommon in fish na the Aba aba is no exception. Their nests can be pretty big, but that is not a surprise for a fish that can get 5 feet in length. The male Aba aba makes a nest with uprooted aquatic plants. He pulls up the plants himself and weaves them into a floating nest that can be 1 meter, or 39 inches, in width. The perimeter of the nest is molded with the mud from the roots of the plants. It is expertly woven. It will be anchored to other plants and have an opening through which the male can enter and depart when needed. A little bit of the top of the nest will stick out of the surface of the water. If the nest becomes dislodged the male will remain with it as it floats down the river.
Inside the plants the male will create a bubble nest. This portion of the nest is made of air bubbles and this is where the eggs will be nestled.
The nest is important for several reasons: The first is to attract a mate. The ladies are attracted by large, well made nests, so the gentlemen will take their time picking the right plants for just the right nest. A few studies have indicated that they prefer plants in Family Poaceae, which are the grasses. The oblong leaves of the grass are perfect for weaving. We have to remember that this animal is weaving a nest. An animal that has no hands is weaving a nest. How extraordinary it that!
The second reason the nest is important is that this is where the eggs will be hidden and held until they hatch. Eggs are between 7mm-8mm, some papers have even said 10mm. That is a very large fish egg. 
Once the eggs are in the nest and fertilized, the male aggressively protects the nest from all predators. It will not hesitate to attack any living thing that comes near, including humans. These guys have no fear, especially when protecting their young. 
As I mentioned before, the nest have an opening for the Aba aba to enter and leave. When they are inside the nest, the male has been seen agitating the water around the eggs. We are not sure why they do this, but it could be to make sure the eggs are well oxygenated and/or keeping the eggs clean of debris. Either way the male is doing a great job keeping the eggs healthy.
I did not find any reference to how long it takes the Aba aba fry, that’s right baby fish are called fry, to hatch and leave the nest. They will remain in the nest until the yolk is completely absorbed. Until then they are vulnerable to predation and they will stay in the nest under papa’s protection. The fry have long gills to help absorb oxygen from the water, but will also gulp air from the center of the nest as well.
How many eggs are we talking about here? Good question! I love it when you think ahead listeners. Females can lay 800-1000 eggs in a nest. That is a lot a fry to keep track of, but it’s actually a low number compared to other species of fish. Aba aba seem to put more energy into larger, but fewer eggs, and more parental involvement to ensure future generations’ survival. 
I could not find any information about how many nests a female will visit in one breeding season. This may be due to the fact that it is difficult to follow them in the rivers where they live, especially during the rainy season when sediment is stirred and flowing freely in the rivers, or it could be that no one has pursued this avenue of study.  
Male and females both have singular reproduction organs. The males have a single testis and the females have a single ovary. This probably limits the amount of eggs they can lay and fertilize. 
Aba abas will complete this reproductive cycle twice a year in the wild following the rainy seasons. In captivity, it may be a different story. The Aba aba I worked with at the zoo was a male. We know this because we gave him enrichment toys such as weighted pool toys and copious amounts of plastic aquatic plants. The only thing he ever did with them was make a floating nest. He would weave the plants together and then shove the pool toys up inside the nest. Sometimes he used the nest like a hammock. Just relaxing inside it and not moving at all. Several times he gave me gave me heart palpitations as I thought he was dead, but it was just one more thing that made me like him.
I’m so happy you joined me for episode three of Aba abas because my third favorite thing about them is their reproductive behaviors.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about the Aba aba.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Aba aba: Habitat

Summary: Where are Aba aba found? Join Kiersten as she tells where you can find these amazing 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
 
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. 
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 second episode of Aba aba, or Gymnarchus niloticus, and the second thing I like about this little known fish is where they are found. Let’s talk about where in the wild this fish is naturally found and what kind of habitat they tend to like best. This episode may be a bit shorter than most, but I promise to make up for it in future episode of this series.
In episode one we found out that the Aba Aba is found in Africa. They can inhabit bodies of fresh water in the Nile, Turkana, Chad, Niger, Volta, Senegal, and Gambia basins. It is wide spread throughout West African countries of Egypt, Benin, Burkina Faso, Central African Republic, Chad, Cote d’Ivoire, Ethiopia, Ghana, Kenya, Mali, Mauritania, Niger, Nigeria, Senegal, South Sudan, Sudan, Uganda, and Gambia. It has been reported in Cameroon, where it is an introduced species, but identification here still needs further confirmation. By widespread I mean that they can be found in various bodies of freshwater such as lakes and rivers in these areas but they are sparsely spread. 
These fish need fairly large territories, remember that can get up to five feet in length and weigh 42 pounds, and spend most of their lives as solitary individuals, so therefore, they are sparsely spread throughout their natural habitat.
Now that we know where in the world to find these amazing fish, what kind of habitat are we looking for? We know they like freshwater and can be found in lakes and rivers. They will most often be found in areas with dense aquatic vegetation. They use this to hide from larger predators and to help camouflage themselves from prey items. 
In rivers, they favor the edges of the water near the banks to keep out of the rushing currents toward the middle. Don’t get me wrong, they can swim well, but the edges host the plants they need to rest in during the day. Aba aba are nocturnal, so they are most active at night and they spend their days resting in the vegetation. They can use the plants a bit like a hammock, supporting them while they sleep.
Aba aba fish have very small eyes and are a bit sensitive to light so this is another reason to live in and around thick vegetation. 
Their behavior is seasonally influenced by the rains of this continent, as are many species of animals that live on the African continent. When the rains come breeding season begins, but you’ll have to wait for the next episode to find out the unique breeding behaviors of the Aba aba.
That’s it for the second episode of the Aba aba. Thank you for joining me to find out where this amazing fish lives because it is my second favorite thing about them. 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about the Aba aba.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Aba aba Fish

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 cooler than they already are? Well, they are electric! Didn’t see that coming did you?
Aba aba are capable of generating a weak electric current that helps them find prey in low light. Yes! Aba aba are electric fish.
I became fascinated by this fish when I worked with one at one of the zoos where I worked. As soon as he was transferred to our department, he quickly became one of my favorite animals to feed, clean, and develop enrichment for. That’s right these fish are great problem-solvers and we had to give him things to rearrange inside his tank to keep him busy. It was my pleasure to work with him and I like to think he appreciated the attention we gave him, as well.
That is it for the first episode of Aba aba. I hope the overview of this animal has you excited to learn more because my first favorite thing about the Aba aba IS the Aba aba.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about the Aba aba.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: Conservation

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 from being on the menu internationally, but locally some people do hunt them for food. It is probably an acquired taste and you need to know how to prepare the meat just right to make it palatable. 
It is nice to report on species that are still thriving in our ever changing world and I am glad to know that local conservation effort exists for all three species on Screamers.
Thank you so much for joining me for another series of Ten Things I Like About… I learned a lot about the Screamer as I wrote this series and I hope you learned a lot by listening. My tenth favorite thing about Screamers is conservation.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
I will be taking a bit of a break at the beginning of summer, so join me again in July for a brand new series on an unknown or misunderstood creature. 
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: Eyes and Beak

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 bills are flat and wide with some serration on the inside to help grasp aquatic grasses, but as we know Screamers have a hooked beak reminiscent of a raptor beak.  
Hooked beaks help raptors tear apart their prey to facilitate swallowing. If the Screamer eats plant material why does it have a small hooked beak? It has to be hard work to get enough food using a smaller beak to pick up leaves, flowers, and plant roots. It is so much effort for a food item that is low in calories. Once again there is no easy answer to this question, but new study discovered that what a bird eats isn’t the only determination of beak size and shape. Turns out we should be thinking about the birds beak in the same manner that we think of our hands. Beaks are not just for eating, they are for manipulating the environment. 
Screamers may have hooked beaks to help them build nests, feed their young, or manipulate their environment in ways that we have yet to discover. Once again Screamers are pushing the boundaries of normal avian behaviors.
Thank you for joining me for the ninth episode of Screamers. I hope you learned something new, I know I did and my ninth favorite thing about Screamers is their eyes and beaks.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for the final episode of Screamers.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: Vocalizations

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 day. Morning brings Moo-Co calls to greet the morning and talk to the neighbors. Remember this species of screamer lives in small groups of 5 to 10 with everyone helping define a territory, so knowing that everyone made it through the night and where they are is important.
If nothing really happens during the day, the screamers are quiet but, if they decide to move locations or other screamers encroach on their territory, things can get loud.
Moo Co calls are made when groups decide to move locations and can be heard during take-off when individuals are close together. If an individual within an established group changes location they are quiet upon take-off but are greeted loudly with honking upon landing.  Honking between isolated groups, up to a mile apart, happens a lot. One group will begin honking with occasional trumpet calls and then nearby groups will respond. This kind of check-in can last about 20 minutes and involve up to seven different groups. We are not entirely sure why they do this, but it is certainly a great way to get information about your surrounding environment. 
Honking and trumpeting erupt when other groups of screamers land near territory boundaries or cross over into an established territory. 
There is one last call we need to discuss. Screamers also produce a nonvocal sound using the unusual subcutaneous air sacs we discussed on the last episode. This call is a low-intensity sound created during pair bonding activity and family greetings. It is produced with the body in a horizontal position, with the tail slightly lowered. Feathers in the middle of the neck region are repeatedly raised and flattened in concert with this “ugh” sound. We are not exactly sure how Screamers produce this sound, but it is hypothesized that it is created by forcing air through the subcutaneous air sacs in the neck. Well, Screamers just get more and more interesting with each episode.
I hope you enjoyed this look at Screamer vocalizations because it is my eighth favorite thing about this amazing bird.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next we for another exciting episode about screamers.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: More Anatomical Anomalies

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 the atmosphere while employing continuous, unidirectional, efficient flow of air. Amazing! This respiratory system it what allows birds to process enough oxygen to fly and prevent them from overheating when they are in flight. Pretty important stuff.
Screamers have an oddity associated with their respiratory system. They have subcutaneous diverticula, also known as, pneumatic diverticula, subcutaneous air cells, or superficial air cavities, all over their body. These bubbles are full or air and lay between the skin and muscles. These structure appear to be extensions of their respiratory system. 
Why do they have these extra air sacs? Once again, we don’t know. Screamers are a riddle wrapped in a mystery inside an enigma. But boy it does make them fun!
We can make educated guesses as to why they might need these, such as Screamers fly at unusually high altitudes and the excess air sacs ma  y help in buoyancy keeping the body light. This combined with their highly pneumatic bones that we learned about in the last episode could explain the extra air sacs.
These subcutaneous air sacs may also help them extract as much oxygen out of thin air as possible. We do know that it gives them a strange crackling noise when they walk, and keeps them safe from hunters. The extra air sacs make them unappetizing to the human palate. 
Well, that’s it for episode seven of Screamers and I hope you found it as fascinating as I did because my seventh favorite thing about them in their anatomical anomalies.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about Screamers.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: Skeletal Anomalies

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 and deflate the lungs. Birds rely on the movement of their sternum to breathe. That’s why it’s so important to hold birds properly when restraining them for veterinary care or scientific measurements. If you put too much pressure on the sternum, you can suffocate them. 
Studies have shown that the uncinate processes are integral in avian respiration acting as attachment site for muscles used in the mechanics of breathing. The presence of an uncinate process on the ribs of a bird increased the respiration function by 2 to 4 compared to a bird without an uncinate process. These processes allow the bird to more easily rotate the dorsal ribs forward, pushing the sternum down and inflating the lungs. Seems pretty important to me!
The length of the uncinate process varies by species and seems to be impacted by what physical activities the bird partakes in most often, for example walkers versus divers versus non-specialist birds.
Further studies have shown that the uncinate process is actually important in both inhalation and exhalation in birds. I don’t think I need to tell you this, but this little bone extension seems like a mighty useful tool and one that all birds should have, but the title of the episode isn’t Screamers: Skeletal Normalities but Screamers: Skeletal Anomalies. 
So, here it is folks. Screamers do not have uncinate processes. That’s right, they do not have these little bones that are so helpful for breathing. And once again, we don’t know why. None of the three species of Screamers have uncinate processes. They can breath, clearly they are living creatures that process oxygen just like the rest of us, but unlike most species of birds they do not utilize uncinate processes to do it.
Every episode I write about these incredible birds makes me like them more and more. I hope you think so too because my sixth favorite thing about Screamers is their skeletal anomalies.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about Screamers.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Screamers: Spurs

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 and why did Screamers develop these spurs in the first place. Wing spurs occur in other bird species besides, Screamers. Yep, that’s right, other bird out there have wing spurs. Most of them are smaller birds than Screamers and have only one spur per wing. Well developed wing spurs actually occur in Family Anhimidae: these are our Screamers, in Family Anatidae (ducks and geese): only 2 species out of the 144 species and they have only one spur, Family Jacanidae (jacanas): only 2 out of 7 species and they have only one spur, and Family Charadriidae (plovers): only 10 out of 25 species and they have one spur.  
The spur on most species is an extension of modification of the process of metacarpal 1 with serves as the attachment area for the extensor muscles. If you feel this bone in almost any species of bird you can feel a point or knob, so all species had the potential to develop a spur. It varies depending on the flight needs of different species. So why did some birds develop this spur?
If we look at the species that have spurs in modern times, most of them nest on the ground, and spend a lot of thier lives on the ground in water or on water. To successfully protect your mate and young you may depend on using your wings as weapons to fight off predators. When these species of bird did that, the presence of this modified bone increased their survival rates, so this could be the explanation for the evolution of the spur in these species. The bone was playing double duty, a base for the muscle attachment and a useful weapon. I think this is just another instance of nature making so much sense. Man, nature is wicked cool.
I hope you were surprised by this close up look at Screamer’s spurs because it is my fifth favorite thing about them.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
Join me next week for another exciting episode about Screamers.  
    
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.