Monday, August 31, 2015

Cow Pies Can Make You Smarter and Less Stressed

It seems like everyone is running around buying school supplies and books, registering for classes, and fretting about how hard it is going to be to learn another whole year’s worth of stuff. The secret to success, it turns out, may lie in cow dung.

A cow pie. Photo taken by Jeff Vanuga at
the USDA available at Wikimedia Commons.
Recent research has highlighted the important role that microbes living in animal digestive tracts have on host animals’ health and behavior. This influence of our gut microbes on our behavior is called the microbiota-gut-brain axis. Many of these microbes have long-standing populations that reproduce and spend their whole lives in our guts. Because our digestive tracts do not have much oxygen, these species are anaerobic (do not require oxygen to live). However, our gut communities also have more transient aerobic members (species that do require oxygen to live) that come in when they are ingested and die or leave with the droppings. One of these transient aerobic intestinal citizens is Mycobacterium vaccae (or M. vaccae for short), an aerobic bacterium that naturally lives in soil, water, and yes, cow dung.

When mice are injected with heat-killed M. vaccae, they develop an immune response that activates their brain serotonin system and reduces signs of stress. Serotonin is a neurotransmitter that is found in the brain and is involved in regulating alertness, mood, learning and memory. In fact, many antidepressant drugs work by increasing the amount of available serotonin in the brain. Interestingly, serotonin is also found in the digestive system, where it plays a role in digestive health. Since M. vaccae can increase serotonin function, and serotonin reduces anxiety and improves learning, researchers Dorothy Matthews and Susan Jenks at The Sage Colleges in New York set out to test whether eating live M. vaccae could reduce anxiety and improve learning in mice.

A drawing of the mouse maze used by Dorothy and Susan.
This image is from their 2013 Behavioural Processes paper.
The researchers developed a Plexiglas mouse-maze with three difficulty levels, where each increase in difficulty was marked by more turns and a longer path. They encouraged the mice to run the maze by placing a tasty treat (a square of peanut butter on Wonder Bread™) at the end of the maze. Half of the mice were given live M. vaccae on the peanut butter and bread treat three weeks and one week before running the maze, and then again on each treat at the end of each maze run. The other half were given peanut butter and bread without the bacterial additive. The mice then ran the maze roughly every other day: four times at level 1, four times at level 2 and four times at level 3. Each maze run was video recorded and the researchers later watched the videos to count stress-related behaviors.

The mice that ingested M. vaccae on their peanut butter sandwiches completed the maze twice as fast as those that ate plain peanut butter sandwiches. They also had fewer stress-related behaviors, particularly at the first difficulty level of the maze when everything was new and scary. In general, the fewer stress behaviors a mouse did, the faster its maze-running time was. The mice that ate the M. vaccae also tended to make fewer mistakes.

The researchers then wanted to know how long the effects of M. vaccae lasted. They continued to test the mice in the same maze, again with four runs at level 1, four runs at level 2 and four runs at level 3, but for these maze runs no one was given the M. vaccae. The mice that had previously eaten the M. vaccae continued to complete the maze faster and with fewer mistakes and to show fewer stress-related behaviors for about the first week before the M. vaccae effects wore off.

What does this all mean? It means eating dirt isn’t all bad (although I don't recommend eating cow poop). Letting yourself get a bit dirty and ingesting some of nature's microbes could even help you learn better, remember more, and stay calm - especially in new situations. Just something to think about as the school year gets started.

Want to know more? Check these out:

1. Matthews, D., & Jenks, S. (2013). Ingestion of Mycobacterium vaccae decreases anxiety-related behavior and improves learning in mice Behavioural Processes, 96, 27-35 DOI: 10.1016/j.beproc.2013.02.007

2. Lowry, C., Hollis, J., de Vries, A., Pan, B., Brunet, L., Hunt, J., Paton, J., van Kampen, E., Knight, D., Evans, A., Rook, G., & Lightman, S. (2007). Identification of an immune-responsive mesolimbocortical serotonergic system: Potential role in regulation of emotional behavior Neuroscience, 146 (2), 756-772 DOI: 10.1016/j.neuroscience.2007.01.067

Monday, August 24, 2015

The Weirdest Animals on Earth: 12 Amazing Facts About Octopuses

Photo of a day octopus by
Ahmed Abdul Rahman available
at Wikimedia Commons.
1. The plural of octopus is octopuses. How an English word is pluralized depends, in part, on its origins. Latin words that end in –us are generally pluralized by replacing the –us with an –i (the plural of alumnus, for example, is alumni). But octopus is not Latin – It comes from the ancient Greek word októpous, whose plural is októpodes. Although octopodes is technically correct, since it has been adopted into the English language, the word is now pluralized in the English way, making it octopuses. So octopi is commonly used but not technically correct, octopodes is technically correct but not commonly used and octopussies is just plain wrong.

2. Octopuses are mollusks. This means that they are not only closely related to squid and cuttlefish, but also to clams, oysters, snails and slugs.

3. Octopuses are crazy-smart. They can solve problems, learn from watching others, use tools, and remember experiences. They even have personalities and play with toys. Check this out:

4. Octopuses have nine brains! Rather than a large centralized brain like ours, octopus brains are more like the internet. Their main CPU is a fairly small brain in their head, but each of their eight arms has an additional brain of its own. In fact, two-thirds of an octopus’ neurons are in the arms, which can independently attach to things, push things, and even smell things. They can even react after they have been severed! Not only that, but their severed arms recognize their previous owner:

5. If an octopus loses an arm, it can grow back. Those crazy arms are like the brooms in Disney's Sorcerer's Apprentice in Fantasia!

6. Octopuses are amazing camouflage artists. Their soft bodies can squeeze into ridiculously small cracks and crevices and take on any number of shapes. A 50-pound octopus, for example, can squeeze through a 2-inch hole! They can also change the color and texture of their skin to match their background.

The mimic octopus, the ultimate master of disguise, doesn’t just imitate their background, but also flounders, starfish, poisonous lionfish, and sea snakes.

A vertebrate eye (left) versus an octopus eye (right).
1: Retina, 2: Nerve fibers, 3: Optic nerve, 4: Blind spot.
Image by Jerry Crimson Mann at Wikimedia.
7. Octopuses don’t have visual blind-spots. Most animal eyes detect light patterns when light travels to the retina (the layer in the back of the eye) and falls on photoreceptor cells, causing the cells to send electrical signals through the optic nerve to the brain. Vertebrate photoreceptor cells face backwards, so their nerve fibers come in front of the retina and then exit the eye together through the optic nerve, creating a small region in the back of the eye with no photoreceptor cells. If light falls on this spot, we literally will not see it, although our brain will compensate for this missing light by imagining what should be there based on the rest of what we see. We call this our blind spot. You can test your blind spot by closing your left eye and focusing your right eye on the “R” below. Move your face towards or away from the screen until the “L” disappears. You can test your left eye by staring at the “L” in the same way.
In octopus eyes, the photoreceptor cells face forwards and the nerve fibers go behind the retina. This means that they have a continuous layer of photoreceptor cells and no blind spot.

8. Octopuses are more blue blooded than police officers. Their blood is truly blue, due to the fact that they don’t have hemoglobin, our respiratory pigment that contains iron and turns red when it binds to oxygen. Rather, they have hemocyanin, which contains copper and turns blue when oxygen binds to it.

9. Octopuses have three hearts! They have two small hearts that each pump blood through the gills and a main systemic heart that collects the blood and pumps it through the circulatory system.

10. Octopus ink is a defensive chemical concoction. It not only obscures the view of an attacker, but it also contains a chemical that irritates the predator’s eyes and temporarily paralyzes its sense of smell.

11. Octopuses bite with a bird-like beak and venomous saliva, which is mostly used to subdue prey. Of the approximately 300 octopus species, only the small blue-ringed octopus is known to be deadly to humans.

12. Octopuses die after they mate for the first time. And they mate in an odd way too: males use the tip of their third arm on the right to either insert their spermatophores (sperm packets) directly into the female’s tubular breathing funnel or he just hands it to her (The tip of the third right arm can be used to tell if an octopus is male or female). If he hands it to her, she accepts it with one of her right arms (we don’t know why they’re right-handed this way). Then the males go off to die. The females eventually lay up to 400,000 fertilized eggs, although they can wait months before they do this. She tends them and guards them at the exclusion of all else until they hatch, at which point her body rapidly deteriorates as her cells die off.

Monday, August 17, 2015

Steroids Won't Help if You're a Loser

The more we study physiology and behavior across groups of animals, the more we find we have in common in the types of behaviors we express and the biological machinery of how our bodies influence what behaviors are expressed and when. But similarity does not mean the same. Sometimes seemingly small physiological differences can have big behavioral consequences.

A snuggly California mouse pair. Photo from the Marler lab.

A loner white-footed mouse. Photo by the National Park Service.

Today I am thinking about a story of two very closely related and similar species of mice and how their personal experiences make all the difference in how testosterone affects them. Check it out here.

Monday, August 10, 2015

Caught in My Web: Funky "New" Species

Image by Luc Viatour at Wikimedia.
Given the rate of extinction of creatures great and small, you may be surprised to learn that we discover about 18,000 new species every year! For this edition of Caught in My Web, we explore some of these new-to-us species.

1. Jessica Schmerler explains how animals are classified and named and has a fun slideshow of 2014's top 10 interesting animals at Scientific American.

2. Jane Lee at National Geographic talks about a newly discovered deep sea anglerfish with big teeth, spikes on its snout and a crazy-looking lure on the top of its head!

3. Justine Alford at IFLScience! shows us a newly discovered species of peacock spider.

The male dons a blue mask is is about as cuddly as a spider gets. Check out his dance here:

4. Stephanie Pappas at livescience shows us an adorable newly discovered jelly-bean sized masked frog.

5. Against conventional wisdom, a newly discovered species of frogs gives birth to live young! Dr. Dolittle at ScienceBlogs tells us all about it.

Monday, August 3, 2015

Cooperating for Selfish Reasons

An Ethiopian Wolf photographed by Gert Vankrunkelsven.
Image available at Wikimedia.
If you were a young adult Ethiopian wolf, you would have a choice to make: Should you be a member of a monogamous breeding pair or a helper to an already established breeding pair (who are probably your parents)? The choice seems obvious, right? I mean, who wants to be a helper? Why should you forgo all the glory and status of being part of the breeding pair to be a babysitter?

Today I am revisiting my thoughts on the motivations to cooperate from an article I wrote in the early days of The Scorpion and the Frog. You can read the article in it's entirety here.

Monday, July 27, 2015

Y'all Tawk Funny, Doncha Know

All of our struggles for dialectal conformity (admit it, even you have tried to talk like the cool kids at times) have come from the fact that we learn language through both vertical and horizontal transmission (and no, I’m not talking about the way STDs are spread). We learn language both from our parents (vertical transmission) and our peers (horizontal transmission). We now suspect that orcas (also called killer whales) do too.

Photo by Olga Filatova.
Today I am revisiting my thoughts on dialects, learning languages, and orcas from an article I wrote in the early days of The Scorpion and the Frog. You can read the article in it's entirety here.

Monday, July 20, 2015

How We Know the Colors of Prehistoric Animals

Image from Vinther's 2015 paper in Bioessays.
Through their studies of bones, fossils, and geology, paleontologists have uncovered the prehistoric worlds of Earth's past. We watch movies and TV shows of computer generated versions of long-extinct dinosaurs, fish, birds, and even mammals and it seems obvious how we know about the sizes and shapes of these animals...but how do we know what their colors were like? A new scientific field is emerging, called paleocolor (or palaeo colour, if you're British), in which scientists use fossils, chemistry, cellular biology and comparative biology to reconstruct the color patterns and related behaviors of animals long since passed.

Today at Accumulating Glitches, I discuss the major findings of paleocolor and how we know what colors the dinosaurs and other long-extinct animals actually were. Check out the full article here.

Further reading:

Vinther, J. A guide to the field of palaeo colour, Bioessays, 37, 643-656 (2015). DOI: 10.1002/bies.201500018.

Monday, July 13, 2015

Caught in My Web: Online Animal Behavior Resources

Image by Luc Viatour at Wikimedia.
I often receive questions from readers on how to find out more about a particular topic: How do baboon troops make decisions? Do other species have slaves? Where can I learn more about how hormones affect behavior? In addition to this site, there are many online resources out there to learn more about animal behavior. Here are a few of my favorites:

1. The Conversation is one of my all-time favorite news and information sources. It is a news website with articles on practically every topic that are written by the academic experts that study them. They have a team of editors to help with the journalistic process and writing, resulting in articles that are fascinating, understandable and incredibly informed and accurate. The Conversation launched originally in Australia in 2011. It has since launched regional versions in the UK in 2013, in the US in 2014, and in Africa in 2015. You can search by topic, and their animal behavior articles can be found here.

2. The Nature Education Knowledge Project has a number of articles covering a wide range of topics in animal behavior at basic, intermediate and advanced levels. The Nature Education Knowledge Project was a project by Scitable, a free online teaching/learning source that has high quality educational articles, videos, blogs and other resources in the sciences. Scitable is produced by the Nature Publishing Group (which also publishes journals and magazines such as Nature and Scientific American).

3. Alberto Redondo Villa from University of Córdoba in Spain has a fantastic web-TV channel on animal behavior. Check it out here.

4. Isabella Rossellini, Italian model, actress and filmmaker, has several incredible series of short (1-5 minute) videos on animal sexual behavior in which she plays a different species in each video. The original, called Green Porno, was followed by Seduce Me and Mammas. If you haven't seen it yet, it is a fun way to spend a rainy afternoon. Here is one on earthworm sex:

5. If you are interested in taking a free college-level course on the topic, The University of Melbourne offers an animal behavior course (called “Animal Behaviour”, because they’re Australian) at Coursera. Learn more about the course and the next available dates here.

Monday, July 6, 2015

Song Battles With Other Species Can Change Your Tune

Many animals defend territories from members of their own species for mating, breeding, and finding food and they often use species-specific vocalizations to do this. Defending a territory can be risky and costly in both energy and time, so even territorial animals generally don’t waste this effort on other species that do not share their same food and breeding needs. But what do you do if you live around another very similar species that has the same needs that you do? Can two species learn to speak each other’s languages to live in territorial harmony?

A common nightingale.
Photo by Frebeck at Wikimedia Commons.
A thrush nightingale.
Photo by Locaguapa at Wikimedia Commons.
Today at Accumulating Glitches, I tell the story of two species of nightingales and how they are learning to sing each other's songs to defend their territories! Check out the article here.

Monday, June 29, 2015

Loony Locomotion (A Guest Post)

By Emma Doden

For those of us who have worn fins while snorkeling or swimming before, we know how much faster you are able to cut through the water with them on your feet. But as soon as you try to walk on land with those big flippers on, that grace and speed turns into awkward and ungainly steps. You have to concentrate very hard on not falling flat on your face and find yourself thinking that your own two small feet are much more convenient for walking on land than the flippers.

The common loon in flight. Notice how far back on the body its feet are placed!
Photo by Ano Lobb from Wikimedia Commons.
The common loon is a familiar flipper-footed bird for those of us residing in the Northern Midwest. Found on many lakes in the North Woods from late March to September, their black and white plumage, ruby red eyes, and haunting calls make them unforgettable. However, just like any other waterbird, as soon as they come onto land, all of their beauty and poise vanish. Loons do not have the luxury of removing their flippers when they come onto land. Instead they flip and flop clumsily on their bellies, probably feeling just as frustrated as any person frog-stepping with flippers on.

So why do loons have so much trouble walking on land?

Because most of their lives are spent in water, the common loon’s legs and feet are located extremely far back on their bodies, allowing them to swim and dive more efficiently. Loons don’t use their wings to aid in propulsion while underwater, so they need all the power they can get from their legs and feet to catch tasty fish.

The placement of their legs means that they must slide on their belly while on land. Their legs can’t support the weight of their body and so they instead use them to push off of the ground and slide forward. The only time you will find a loon on land is for mating or nesting. Common loons will build their nests on the shore, usually no more than 5 meters from the water, because it takes a lot of effort to belly flop even that short distance!

Watch the video below to see how comical a loon looks when stranded on land:

Though loons are strong fliers as well as divers, coming in for a landing can also be challenging. Their legs are too far back to thrust forward and use as landing gear, so they stick them straight back and make a splash-landing on their bellies, penguin style!

But what makes their legs and flippers so good for swimming and diving?

Common loons propel themselves through the water with sideways strokes of their legs and feet, similar to oars on a boat. Diving birds have leg bones with a long spike-like extension at the knee where very strong muscles connect. This part of their leg acts like a lever when a loon paddles, allowing the leg and foot to be powerfully propelled through the water. Each foot is fairly large with webbing between each toe. When a loon paddles through the water, the webbing fans out and the foot rotates slightly in relation to the body on the downstroke, allowing the maximum surface area to push off of the water. On the upstroke the toes will compress together and the webbing will bunch up so that there is minimal resistance cutting through the water. The motion of the foot splaying out and compressing in with each stroke creates an efficient mode of transportation for the water-loving loon. With legs and feet like these, they are able zoom through the water as fast as fish and dive up to 200 feet!

Loons rarely come onto land, and so it is not often that you will find one of these majestic creatures floundering through the mud of a lakeshore. You are much more likely to see them gliding effortlessly across a lake, until they disappear below the surface. Then you can imagine them easily hunting fish using their powerful legs and feet to propel them while diving. Even more so than wearing flippers to help you swim, just think how much faster you could be in the water with the streamlined body and strong legs and feet of a common loon!

To learn more about common loons and their flipper-foot conundrums visit these websites:

Piper, Walter. The Loon Project.

The Cornell Lab of Ornithology. 2011. Common Loon, Life History. All About Birds.

Evers, David C., James D. Paruk, Judith W. Mcintyre and Jack F. Barr. 2010. Common Loon (Gavia immer), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; The Birds of North America Online.

Michigan Department of Natural Resources. 2014. Common loon (Gavia immer).

Shearwater Seabird Osteology. 2013. Divers/loons: Osteology.