Tuesday, September 19, 2017

Caught in My Web: Spiders!

Image by Luc Viatour at Wikimedia Commons
Spiders creep most of us out. But let’s face it: they are pretty darn amazing! For this edition of Caught in My Web, we appreciate our 8-legged friends.

1. Did you know that sea spiders use their gut as a heart?

2. And lace sheet weaver spiders make optical illusion webs to lure nocturnal moths.

3. Even our run-of-the-mill spiders are pretty amazing, when you really look at them. Watch this amazing timelapse of a garden orb web spider building a web:



4. Portia, the spider-hunting spider, is a genius with super-powers:


5. And researchers at the National University of Singapore have now found that personality affects how these smart spiders hunt.

Tuesday, September 12, 2017

I Know I Want to Work With Animals. Now What?

"What to do? What to do?" Photo by Dmitry Rozhkov at Wikimedia Commons

Does this sound familiar: “I know I want to work with animals, but I don’t know if I want to be a vet. What should I be? How do I prepare for a career if I don’t even know what I want to do?”

If this is you, don’t panic. There are many professions that work with animals, and luckily, there is a lot of overlap when it comes to qualifications for those jobs. This means that there are certain steps that you can take to make you competitive for a range of jobs that work with animals and you don’t have to decide today exactly what that job will be.


Experience With Animals


To get a job that works with animals, you need to be good at working with animals. Seems pretty obvious, but it can be more difficult than you think. To get good at something, you need experience, and to get experience, you need a position, and to get a position, you need to be good at it… AARRGG!

The trick is to get your foot in the door: Train your pets to compete in obedience or agility competitions. Work in a pet store, groomers, or pet boarding kennel. Volunteer at a local animal shelter, animal rehabilitation center, veterinary clinic, or zoo. If you are considering colleges, ask about clubs, internships and other opportunities that they offer to get animal experience.

It is also important to keep a record of all your animal experiences; List all of the experiences by category or position and keep track of your hours. This will be invaluable information to put on applications in the future.


Experience With People


We often forget that many positions that work with animals also require a strong ability to work with people. Veterinary clinics work with pet owners; Zoos and aquariums teach the public; Animal trainers would be more accurately called “pet-owner-trainers”. As counterintuitive as it may seem, you can improve your marketability to animal jobs by improving your people skills.

First and foremost, don’t shy away from face-to-face contact. Yes, texting and emailing is faster and easier, but an actual conversation can have a much better outcome and helps develop your people skills without a conscientious effort. Beyond that, pay attention in English classes, read books, and seek out opportunities to interface with actual people. Jobs in retail and as receptionists are good for this. Look for opportunities in the field of education, perhaps as a tutor or assistant. Volunteer to interact with people in nursing homes, hospitals, or shelters. And again… keep track of your hours.


Education


Educate yourself for the job you want.
Photo by raider of gin at Wikimedia Commons.
There are jobs that work with animals for people with all levels of education, so you may want to pursue the level of education you need for the job(s) that you want.

Before you complete high school, you may be eligible to be a: volunteer (at an animal hospital, rehabilitation center, zoo, aquarium, or animal shelter), pet store employee, pet boarding employee

With a high school diploma, you may be additionally eligible to be a: veterinary assistant, veterinary receptionist, domestic animal care staff, domestic animal trainer, animal control worker or dog warden, animal farmer or breeder

With a specialized 2-year degree, you may be additionally eligible to be a: veterinary technician or veterinary technologist

With a 4-year degree, you may be additionally eligible to be a: zoo keeper or aquarist, educator, wildlife rehabilitator, wildlife animal trainer, assistant research biologist, animal care manager, animal cruelty investigator

With a DVM, you may be additionally eligible to be a: veterinarian (at a clinic, hospital, zoo, or university), research biologist

With a PhD, you may be additionally eligible to be a: research biologist


Are you already in an animal-related career? Share your tips in the comment section below! And for more advice for working with animals, go here.

Tuesday, September 5, 2017

A New Key to the Story of How the Sexes Have Come to Be


In the beginning, we are all male and female… More specifically, we are all in between male and female. So what makes our embryonic selves choose and follow a developmental path to becoming the sex that we are today? New research has dramatically changed our understanding of this process.

During early embryonic development, all mammals develop a single pair of gonads that are neither testes nor ovaries, but have the potential to become either. Likewise, the external genitalia at this early stage has the potential to become either a penis and scrotum or a clitoris, vagina, and labia. Two pairs of ducts develop to connect the gonads to the undifferentiated external genitalia: One set of ducts, the Wolffian ducts, would become the epididymis, vas deferens, and seminal vesicles if this animal becomes male. The other set of ducts, the Müllerian ducts, would become the oviducts, uterus and innermost part of the vagina if this animal becomes female. So what determines if a given animal will develop male or female reproductive anatomy?

Early in development, mammalian embryos have one set of gonads that has the potential to become either testes or ovaries (here labeled as "bipotential gonad"). These gonads are connected the the developing external genitalia by two sets of tubes: The Wolffian ducts become the reproductive tracts in males and the Müllerian ducts become the reproductive tracts in females. The ducts that do not become reproductive tracts typically disintegrate. However, XX female embryos that lack the COUP-TFII protein do not dismantle their male-like reproductive tracts. Figure from Swain, 2017.

The sex of a mammal is determined by the combination of sex chromosomes it has. If the mammal has two X chromosomes, it will likely become female, and if it has an X chromosome and a Y chromosome, it will likely become male. The story physiologists have been telling for decades is that there is a single gene located on the Y chromosome, called the SRY gene, that single-handedly makes an embryo become a male. When expressed, the SRY gene produces a protein, called testes-determining factor, which interacts with the cells of the undifferentiated gonads to turn them into testicular cells. These newly formed testicular cells produce two key hormones: testosterone, which causes the Wolffian ducts to become the epididymis, vas deferens, and seminal vesicles, and anti-Müllerian hormone (AMH), which causes the Müllerian ducts to degenerate. In other words, if an animal has a Y chromosome, it will typically have an SRY gene that will trigger the sequence of events that causes the animal to develop into a male. If the animal does not have the Y chromosome, it will typically become female. However, it is not just the lack of a Y chromosome that can make a female; Any disruption of this pathway (such as an SRY gene that is not expressed, or the lack of testicular hormones) typically causes the animal to develop into a female. For this reason, females in mammals have been called the default sex. The scientific understanding since the 1950s has been that, in mammals, the development of a male reproductive system is an active process and the development of a female reproductive system is a passive process. However, a new study reveals that the process of becoming female mammal is not as passive as we have thought.

Fei Zhao, Humphrey Yao and their research team at the National Institute of Environmental Health Sciences and Baylor College of Medicine discovered a critical role for a specific protein, called COUP-TFII, in the active process of becoming a mammalian female. The research team examined female mouse embryos (which lack a Y chromosome, and hence an SRY gene) that had been genetically modified to lack a particular protein called the COUP-TFII protein. They compared these genetically modified XX embryos to genetically typical XX mouse embryos. When the unmodified XX embryos had developed to have only Müllerian ducts (the “typical” female reproductive pathway), the XX embryos without COUP-TFII protein retained both Müllerian and Wolffian ducts! Unfortunately, these XX mice that lacked the COUP-TFII protein died shortly after birth, so it was difficult to tell if this developmental process would have continued. The research team cultured reproductive organs of XX mice with and without COUP-TFII protein and found that this developmental trajectory likely would have continued after birth.

Images A and B show the reproductive tract from the side (A) and as a cross-section (B) in a "typical" XX female mouse embryo. Images D and E show that XX females that lack the COUP-TFII protein retain both Müllerian (pink arrows) and Wolffian (blue arrows) ducts. Figure from Zhao et al., 2017.

We know that testosterone helps promote the development of Wolffian ducts in XY males, so the most likely explanation of what they witnessed is that the lack of COUP-TFII protein somehow increased action of testosterone in these genetically modified XX embryos. The researchers ran a number of tests to explore this possibility. Testosterone is mostly produced by the gonads, so they compared the gene expression and enzymes of ovaries of unmodified XX mice with the ovaries of XX mice that lacked the COUP-TFII protein, and they found no differences that pointed to differences in testosterone production. They then considered the possibility that testosterone was produced somewhere else in the body, but the XX mice that lacked the COUP-TFII protein did not have more masculine body features compared to the unmodified XX mice. Finally, the researchers gave extra testosterone to the mother mice that were pregnant with unmodified XX mice and XX mice that lacked the COUP-TFII protein. The extra testosterone did not affect any of the mouse pups; it did not cause the Wolffian ducts of the XX mice that lacked the COUP-TFII protein to regress. Together, the researchers found that no, XX embryos that lack COUP-TFII protein do not have any more testosterone-like activity than their non-genetically modified XX sisters. This means that testosterone alone is not enough to keep Wolffian ducts.

This research has shown us that for the Wolfian ducts to go away during the reproductive development of a mammalian female, they need to be actively dismantled using a biochemical process (similar to how AMH dismantles Müllerian ducts during male reproductive development). COUP-TFII protein appears to be the chemical in charge of triggering this process. Female mammals are not the passive result of simply not becoming male, as has been taught in physiology classes for decades. Becoming a female mammal requires a process all its own, and we are only now starting to learn what that is.


Want to know more? Check these out:

F. Zhao et al. Elimination of the male reproductive tract in the female embryo is promoted by COUP-TFII in mice. Science. Vol. 357, August 18, 2017, p. 717. doi: 10.1126/science.aai9136

A. Swain. Ductal sex determination. Science. Vol. 357, August 18, 2017, p. 648. doi: 10.1126/science.aao2630

Tuesday, August 29, 2017

The Olympic Athlete of the Animal Kingdom: The Circulatory System of a Horse (A Guest Post)

By Emily Fandrey


How do you judge the abilities of an athlete? Is it all about speed? What about endurance? Strength? How would you judge an animal that can run up to 48 kilometers per hour (30 mph), cover 48 kilometers (30 miles) in a day, or clear a 2.4 meter (8 foot) jump, all while carrying a human on its back? Because of these abilities, the horse (Equus caballus) is often considered to be one of the animal kingdom’s best athletes. The major factor behind horses’ advanced athleticism is their unique circulatory system, specialized for delivering large amounts of oxygen throughout the body.

Image by Paul Kehrer at Wikimedia Commons.

A horse’s circulatory system has three major players: the heart, the spleen, and the frog (and no, this has nothing to do with the animal frog, but rather a specialized unit of a horse’s hoof). Due to these three components, horses have one of the best aerobic capacities in the animal kingdom. Let’s look at a racehorse for example: During a race, a thoroughbred can reach a maximum oxygen capacity (the amount of oxygen the blood can carry) of 200 milliliters per kilogram per minute, meaning 200 milliliters of blood per kilogram of weight (or 3.1 ounces per pound) are transported to the body every minute! This is more than twice the oxygen capacity of the most elite human athlete!

This diagram illustrates the horse’s circulatory system,
including the heart, arteries, veins, and spleen. Diagram by Emily Fandrey.

So let’s break down this superior aerobic system, starting with the horse heart. Typically, a horse’s heart weighs 1% of its total body weight; meaning if a horse weighs 450 kilograms (1000 pounds), its heart will be roughly 4.5 kilograms (10 pounds). If this was true for humans, a 68 kilogram (150 pound) human’s heart would be 0.68 kilograms (1.5 pounds), although the average human heart is only about 0.23 kilograms (half a pound). The horse’s heart functions very similarly to a human heart. It contains four chambers and is responsible for getting oxygen to the body by pumping the oxygen-filled blood. After the body systems have used the oxygen in the blood, this deoxygenated blood enters the heart and is sent to the lungs where the blood is resupplied with oxygen from breathing air. This oxygenated blood reenters the heart and is pumped back out to the body. Because of the size of their hearts, horses are able to supply large amounts of blood with oxygen to the body with each heartbeat, averaging a combined 38 liters (10 gallons) per minute (this is about ten times as much as a human).

Horses also have very different heart rates than humans during rest and exercise. A horse’s resting heart rate is 28-44 beats per minute (bpm), compared to the average human’s, which is 60-80 bpm. During exercise, a human’s heart rate is 90-170 bpm, depending on age. A horse’s heart rate, however, rises to 80 bpm during a walk, 130 bpm during a trot, 180 during a canter, and 240 bpm while galloping. At top speed, the fast beating heart of the horse is what allows the heart to pump much more blood to the body than a human, increasing their athletic abilities.

A diagram of how the horse’s frog sends blood back to heart quickly,
working against gravity. Diagram by Emily Fandrey.

With the long legs of horses, the heart also has to work against gravity to get blood from the limbs back to the heart. To combat this, the horse has its “frog”. For a horse, the frog is a vessel-filled tissue structure on each of its four hooves. When weight is placed on the frog, this structure can help the heart work against gravity. How? When the horse’s hoof meets the ground, the ground will push up on the frog, resulting in the frog being compressed and squeezing blood in the vessels out and rapidly up the leg. The frog helps heart work against gravity by sending the blood up the leg and back to the heart, allowing for faster blood circulation, increasing the athleticism of the horse.

The last key factor to the horse’s circulatory system is the spleen. This organ improves aerobic capabilities and the horse’s athleticism. Now, the primary function of the horse’s spleen is to remove damaged blood cells. However, when a horse is relaxed, their spleen will fill with up to 30 liters (8 gallons) of oxygen-filled blood. And then, once the excitement of activities like running or jumping sparks, the spleen will contract and send up to 25 liters (6.6 gallons) of this stored blood back into circulation in mere seconds! So in seconds, the spleen is capable of almost doubling the maximum amount of oxygen the blood can carry, increasing the athleticism of the horse as well.

So if you ever need an excelling athlete on your team, consider an animal with a superior circulatory system: the horse. With a large and powerful heart capable of pumping large amounts of blood, a spleen to provide an extra burst of blood in seconds, and a “frog” to work against gravity, there is no wonder why horse is considered to be one of the world’s superior athletes.


References

Allen, K.J., Young, L.E., and Franklin, S.H. (2016). Evaluation of heart rate and rhythm during exercise. Equine Veterinary Education 28: 99-112. DOI: 10.1111/eve.12405.

Cardiovascular System (2007). In EQUINAvet.

Circulatory System of the Horse (2010). In Helpful Horse Hints.

Equine Circulatory System Vet, Horse First Aid (2012). In Equestrian and Horse.

Norton, J. (2013). The equine circulatory system. In EquiMed: Horse Health Matters.

Monday, August 21, 2017

Caught in My Web: Animal Reactions to A Solar Eclipse

Animation by Locutus Borg at Wikimedia Commons.
A solar eclipse is a rare event that can have dramatic effects not only on us people, but on animals as well. For this edition of Caught in My Web, we think about how animals may respond to such a rare celestial event.







Image by Luc Viatour at Wikimedia Commons.
1. National Geographic shares many ways animals are known to behave in strange ways in response to a solar eclipse.

2. Much of the effect of an eclipse on animal behavior is utter confusion, but many groups will be watching animals to see how they respond.

3. Researchers at the University of Nebraska will be collecting behavior data on GPS-tagged red-tailed hawks to see how the solar eclipse affects them.

4. Some nature centers are studying animal behavior during the eclipse.

5. If you found any animals that freaked out so badly as to injure themselves, check here for advice.

Monday, August 14, 2017

Striving for a Honeybee Democracy

Democracy is hard. And slow. And complicated. But if it is done well, it can result consistently in the best decisions and courses of action for a group. Just ask honeybees.

When a honeybee hive becomes overcrowded, the colony (which can have membership in the tens of thousands) divides in what will be one of the riskiest and potentially deadliest decisions of their lives. About a third of the worker bees will stay home to rear a new queen while the old queen and the rest of the hive will leave to establish a new hive. The newly homeless colony will coalesce on a nearby branch while they search out and decide among new home options. This process can take anywhere from hours to days, during which the colony is vulnerable and exposed. But they can’t be too hasty: choosing a new home that is too small or too exposed could be equally deadly.

Our homeless honeybee swarm found an unconventional "branch". We'd better
decide on a new home soon! Photo by Nino Barbieri at Wikimedia.

Although each swarm has a queen, she plays no role in making this life-or-death decision. Rather, this decision is made by a consensus among 300-500 scout bees after an intense “dance-debate”. Then, as a single united swarm, they leave their branch and move into their new home. At this point, it’s critical that the swarm is unified in their choice of home site, because a split-decision runs the risk of creating a chaos in which the one and only queen can be lost and the entire hive will perish. This is a high-stakes decision that honeybees make democratically, efficiently, and amazingly, they almost always make the best possible choice! How do they do that? And how can we do that?

The honeybee house-hunting process has several features that allow them, as a group, to hone in on the best possible solution. The process begins when a scout discovers a site that has the potential to be a new home. She returns to her swarm and reports on this site, using a waggle dance that encodes the direction and distance to the site and her estimate of its quality. The longer she dances, the more suitable she perceived the site to be. Other scouts do the same, perhaps visiting the same site or maybe a new one, and they report their findings in dance when they return. (Importantly, scouts only dance for sites that they have seen themselves). As more scouts are recruited, the swarm breaks into a dancing frenzy with many scouts dancing for multiple possible sites. Over time, scouts that are less enthusiastic about their discovered site stop dancing, in part discouraged by dancers for other sites that head-bump them while beeping. Eventually, the remaining dancing scouts are unified in their dance for what is almost always the best site. The swarm warms up their flight muscles and off they go, in unison, to their new home.

Each dot represents where on the body this dancer was head-bumped by a dancer for a
competing site. Each time she's bumped, she's a little less enthusiastic about her own dance.
Figure from Seeley, et al. 2012 paper in Science.

What can we learn from these democratic experts? As much as I would love to see Congress in a vigorous dance-debate head-butting one another, I don't think that is the take-home message of choice. Tom Seeley at Cornell University has gained tremendous insight into effective group decision-making from his years observing honeybees, which he shares with us in his book, Honeybee Democracy. Tom has summarized his wisdom gained from observing honeybees in the following:

Members of Highly Effective Hives:

1. share a goal

2. search broadly to find possible solutions to the problem

3. contribute their information freely and honestly

4. evaluate the options independently and vote independently

5. aggregate their votes fairly

All of these critical guidelines can be encapsulated with a single objective: The decision-making body needs to objectively consider a range of information from individuals with diverse backgrounds, expertise, and knowledge. We can apply this to our own human decision-making: It means that if you don't agree with the decisions of your School Board, Town Board, City Council, County Legislature, State Legislature, or National Legislature, then your background, expertise and knowledge are likely missing from the deciding body. Yes, you can write and call your representatives and provide them with part of your knowledge, or you can run for office yourself and make people with your background truly included in the decision-making process.

Running for a human political office is more complicated and confusing than becoming a honeybee scout. No matter what your background is, you will need to work hard to gain additional expertise in campaigning. But now is the time to get into the game: there is a tremendous upswell of support for people that are new to politics. Many organizations provide free training, connections, even financial support to recruit new people with new perspectives. And these days, there seems to be a supportive group for just about everyone who wants to get involved.

If many of your views align with a political party, you can often turn to the party itself for support. Democrats can turn directly to Democrats.Org or the National Democratic Training Committee. Likewise, Republicans can go to EquipGOP or the Republican Leadership Initiative. Support is also available for Libertarians and members of the Green Party.

Private groups provide additional resources for candidates of particular backgrounds. For example, Camp Wellstone is a training program for any progressive candidate, and Run For Something provides additional support for progressives under 35. Additional groups working to promote more diverse representation are the BRAT-PAC for African American candidates, the Latino Victory Project for Latino candidates, and the Gay and Lesbian Victory Fund for LGBTQ candidates. And, my own personal favorite, 314 Action promotes scientists and other STEM-trained candidates.

Women candidates, in particular, have more resources than ever right now. This is tremendously valuable to increasing our decision-making diversity, since although women make up more than 50% of the US population, women make up less than 20% of the National Legislature, and less than 25% of state legislatures. Women candidates of every party and background can get support from IGNITE, She Should Run, the Center for American Women and Politics, and the Women's Campaign Fund. The National Federation of Republican Women specifically supports republican women candidates. Likewise, EMILY’s List and Emerge America provides training for progressive women candidates. Higher Heights supports black women candidates for any office.

Many feel that our hive has been homelessly clinging to our exposed branch for too long. If we are going to make good, well-informed, effective, and efficient decisions, we need open and respectful communication across diverse backgrounds. Increasing diversity in the decision-making body improves the quality of the decisions that affect us all. If honeybees can do it, so can we.


Want to know more? Check these out:

1. Honeybee Democracy by Thomas Seeley

2. Seeley, T., Visscher, P., Schlegel, T., Hogan, P., Franks, N., & Marshall, J. (2011). Stop Signals Provide Cross Inhibition in Collective Decision-Making by Honeybee Swarms Science, 335 (6064), 108-111 DOI: 10.1126/science.1210361

3. List, C., Elsholtz, C., & Seeley, T. (2009). Independence and interdependence in collective decision making: an agent-based model of nest-site choice by honeybee swarms Philosophical Transactions of the Royal Society B: Biological Sciences, 364 (1518), 755-762 DOI: 10.1098/rstb.2008.0277

Monday, August 7, 2017

Drinking Beer Makes You More Attractive… To Mosquitoes

Summer is a time of backyard bar-b-ques, camping, baseball games, beer, and mosquitoes. Ugh, mosquitoes! Have you ever noticed that when a bunch of us are hanging out together outside, some of us get eaten alive by those pesky buggers while others are hardly touched at all? It turns out, differences in how much alcohol we have imbibed may be a factor.

An Anopheles gambiae mosquito ready for a meal. Photo by James D. Gathany
at the Public Health Image Library at Wikimedia Commons.

“No! Say it ain’t so!”

I hate to be the bearer of bad news, so I’ll let the scientific evidence speak for itself.

A research team from the French Research Institute for Development, including Thierry Lefèvre, Louis-Clément Gouagna, Eric Elguero, Didier Fontenille, François Renaud, Carlo Costantini, and Frédéric Thomas, and Kounbobr Roch Dabiré, from the Institute for Research in Health Sciences in Burkina Faso set out to test whether people were more attractive to female mosquitoes after drinking a beer compared to beforehand. They only tested females because only female mosquitoes bite, requiring extra protein for their eggs.

The researchers put groups of 50 hungry female mosquitoes into the end of a special Y-shaped maze that let them fly in the direction of one of two odors. At the end of one arm of the Y-maze was a fan, simply blowing outdoor air through a tent and into the apparatus. At the other end of the Y-maze was a fan blowing air through a tent past a shirtless man and into the apparatus. This shirtless man had either not had anything to drink recently, or had recently drunk either a liter of beer or a liter of water. Between the starting chamber and both ends of the arms of the Y-maze were traps that would capture mosquitoes that had chosen to head that direction (lucky for the shirtless men). The number of mosquitoes caught in both traps combined (compared to the total of 50 that was initially released) was called mosquito activation, and reflected how many mosquitoes were motivated to take off and fly upwind. The proportion of mosquitoes caught in the volunteer-bated trap compared to those caught in both traps combined was called mosquito orientation, and reflected the attractiveness of the volunteer’s odor compared to the control odor.

Image A shows the two tents: one in which the man-bait sat (having consumed beer or water), and the other with no one in it. Air from each tent blew threw a tube (seen in picture B) and then into the building, past the traps and into the downwind box, where the mosquito starting-line was located (seen in picture C). Photos from Lefèvre et al., 2010.

The mosquitoes significantly increased both activation and orientation in response to the beer-drinking volunteers, but not in response to the water-drinking volunteers. That is to say, that the smell of someone that has had a beer motivates more mosquitoes to actively pursue them, and makes them more of a focused target of the mosquitoes. The researchers believe there is an interaction between how our bodies naturally smell and how our bodies break down beer that increases the attractiveness of our odors to mosquitoes. People that were more attractive to mosquitoes before they drank were also more attractive to mosquitoes after they drank. But interestingly, people that were warmer or gave off more CO2 were not more attractive to mosquitoes.

You should know that this research is much more important than just being a drag on your summer bar-b-que. The particular mosquito species that these researchers studied was Anopheles gambiae, the primary vector for malaria in Africa. They did this study in Burkina Faso, a country in West Africa with a high rate of malaria, using a local beer called dolo. Dolo, a fermented sorghum beer with low (3%) alcohol content, is the most common alcoholic beverage in Burkina Faso. So if you are in a place with a high rate of malaria, knowing that you should take extra precautions against mosquitoes when you drink could be a life-saver.

Want to know more? Check this out:

Lefèvre, T., Gouagna, L.C., Dabiré, K.R., Elguero, E., Fontenille, D., Renaud, F., Costantini, C. and Thomas, F. (2010). Beer consumption increases human attractiveness to malaria mosquitoes. PloS one, 5(3), e9546.

Monday, July 31, 2017

How Some Unique Animals Beat the Heat

Man, is it hot out there! While I tuck away in my cool, air-conditioned office, I think about those incredible animals that beat the heat with their own bodies and strategies. It turns out, there are only four major ways to exchange heat with your environment: conduction, convection, radiation and evaporation. The animals that are best equipped for a hot summer are those that take creative advantage of these mechanisms of heat transfer.

"My, what big ears you have!"
"The better to thermoregulate with, my dear!"
Photo by Bernard DUPONT at Wikimedia Commons.
We all exchange heat with our environment wherever our body comes in contact with the environment, namely, across our skin. Animals can increase the rate of this heat-exchange by having a larger surface area relative to the volume of their heat-containing bodies. Big, round animals have a particularly hard time dispersing excess heat, because they have a lot of heat stored in their big bodies, and proportionally not much surface area for the heat to leave from. You may think elephants have such big ears for hearing, but the truth is that they are major temperature-regulation organs. Big, flat body structures provide that added surface area for excess heat to dissipate from. Elephants have large ears with lots of large blood vessels, so they can pump hot blood from the body out to the ears, where they are closer to the cooler environment to dissipate by conduction and convection. The cooler blood then returns to the body core to cool it down.

Built for a life in the cool underground.
Photo by Ted M Townsend at Wikimedia Commons.
Reptiles use a different approach to take advantage of principles of conduction and convection, by burrowing. Burrows create a layer of insulation (usually soil and plant matter) that slows heat exchange and keeps the area below ground a more constant temperature. This means that, compared to the outside, burrows remain cooler in the summer and warmer in the winter. Many reptiles go into their summer burrow in the heat of day and emerge during cooler times of day. Blind lizards, however, take this burrowing idea to an extreme. Blind lizards are a family of legless lizards found in tropical forests. They are small, skinny, and have narrow heads, which make them look more like an earthworm than a lizard, but it also gives them great burrowing efficiency to stay underground and avoid the heat.

A dragonfly exposing as little of his body to the sun
as possible. Photo by Raphael Carter at Wikimedia Commons.
On a hot summer day, we all seek out the shade. This is to reduce the heat we absorb through radiation, and most of this radiation comes from the sun. But what do you do if you can’t find shade? Some dragonflies and damselflies raise their abdomens to aim their rear-ends towards the sun so they can shield themselves from the full-on intensity of the sun’s rays. This body position is called the obelisk posture, because when the sun is directly overhead, the insect’s handstand looks like an obelisk.

Really? Crapping on my own feet?
There has GOT to be a better way.
Photo by Rob Schoenmaker at Wikimedia Commons.
Evaporation is the most efficient way to dissipate heat. Some animals swim, some animals sweat, some animals pant, but vultures and storks win the cooling efficiency award. Vultures and storks. . . poop on their own legs and feet. With this approach, called urohydrosis, the animal releases a mixture of urine and poop through their single excretory hole, called a cloaca, onto their legs and feet. The subsequent evaporation from the high surface area of their long legs helps them to cool off.

So what can we learn from these heat-beating experts (without pooping on ourselves)? If you are hot, spread your body out, stay in the shade, and wet an area of your body with high surface area and exposed blood vessels (namely, your inner wrists and forearms). I’d use water though.

Tuesday, May 23, 2017

Where the Wild Things Are: Amazing Animal Watching Vacations

A modified repost of an original article from May, 2012.

School is winding down, the weather is beautiful and it is time to start thinking about summer vacation! Do you love watching and learning about animals? Then consider one (or more) of these animal watching vacations:


Go to a zoo:

Get a great view of a Siberian tiger at the Toronto Zoo.
Photo by Ber Zophus at Wikimedia.
Zoos allow you to explore the world in a single day: Meandering paths lead you past animals from across the globe. Lions, and tigers and bears, Oh my! But don’t forget the primates, reptiles, birds, and sea mammals. No matter what your animal fancy, you can likely see it at the zoo. Walk through the zoo reading the posted information on each species. Or sit at your favorite exhibit and focus on a single animal. Participate in an educational activity like touching and feeding animals with their keepers, a course, or even a sleepover. And while you are there, learn about how the zoo contributes to animal well-being: Many zoos provide research opportunities to study animal behavior and health (such as the friendship study in crested macaques), support captive breeding programs to restore threatened wild populations, rehabilitate injured or abandoned wild animals, and support habitat conservation.

If you have a local zoo, see what it has to offer. And if you like to travel, consider the San Diego Zoo, the Smithsonian National Zoological Park in Washington, DC, the Singapore Zoo, the National Zoological Gardens of South Africa, or the Toronto Zoo. All of these zoos are well-respected institutions that promote animal conservation and have fantastic educational programs.

Learn more about some of these zoos here.


Go to an aquarium:

Interact with dolphins at the National Aquarium.
Photo by the National Aquarium at Wikimedia.
Aquaria are places of wonder and tranquility. Learn about teleost fish, sharks, rays, crustaceans, octopuses, jellyfish, coral, and many more species that inhabit our oceans, lakes, and rivers. Relax while watching the graceful movements of sea animals and marvel at the agility of apex predators at feeding time. Learn about the many aquatic habitats our planet supports and the amazing diversity of the animals that live in them. Like zoos, aquaria provide research opportunities (such as the individual recognition study in octopuses), support conservation, and have fun educational programs and activities.

If you get a chance, you may want to check out the National Aquarium in Baltimore, the Georgia Aquarium, the Monterey Bay Aquarium, the Aquarium of Western Australia (AQWA) in Perth or L’Oceanogràfic in Valencia, Spain.


Learn more about some of these aquariums here and here.



Take a wildlife tour:

See breathtaking animals in their natural habitat
from the security of your guide's vehicle.
Photo by Brian Snelson at Wikimedia.
If you want to see wild animals in their natural habitats, experienced guides can help you find animals that are often elusive while keeping you safe and preserving animal habitats. Guides can give detailed information about the animals you encounter and can often tell thrilling tales of their own personal experiences. Some even provide lunch.

Maybe your dream has always been to go on an African safari. Consider the Safari Serengeti trip in Tanzania by Overseas Adventure Travel, where you can see animals like Thomson’s gazelles, buffalo, and elephants. Or participate in a North American safari in Yellowstone National Park with Wolf & Bear Safaris by the Yellowstone Safari Company. If a Northwoods flavor suits you, check out Northwoods Outfitters Moose Wildlife Safari in Maine. Or take a Hawaiian vacation and go whale watching with Ultimate Whale Watch in Maui. For a scientific marine vacation, go on an Educational Shark Encounter trip with Fish Finder Adventures based in Ocean City, Maryland. Whatever your dream animal watching trip, a guide can help you bring it to life.


Go somewhere wild on your own:

Kayak by thousands of birds in the Everglades
(but don't forget your anti-bird-poop-hat).
Photo by Matt Magolan.
If you are an independently minded and experienced adventurer, the world is awaiting. And if you want to increase your chances of observing spectacular wild animals in nature, you should go somewhere that has a lot of spectacular wild animals… like Manuel Antonio Park in Costa Rica, where you can see four monkey species, two iguana species, two sloth species, coatis, toucans, vultures, parakeets, and hundreds of other species on a single hike. Or kayak in the Everglades National Park in Florida, where you can see crocodiles, dolphins, manatees and over 350 species of birds. Or SCUBA or snorkel the coral reefs of the Cayman Islands and feel like part of the community of coral, sponges, tropical fish, rays, sharks, and sea turtles.

Learn more about some of these trips here.


We share this world with countless amazing animals. Find your own way to experience, learn about and appreciate them. I’ll go into more detail on these vacations and others in future posts, so comment below and let us know what animal watching vacations you have done and what you are interested in doing in the future.

But for now, I will be going on my own vacation. Don't worry, there will be new The Scorpion and the Frog articles about animals in July!

Tuesday, May 16, 2017

Fatal Attraction: Praying Mantises (A Guest Post)

By Britta Bibbo

We all know the character: an incredibly beautiful woman that seduces the rough-and-tumble action hero, only for him to later find himself chained up over a lava pit with sharks in it! …Or something like that. A “femme fatal” is the idea of a beautiful woman who leads men to their demise. None are more perfect for this role than the female praying mantis. Praying mantis females practice the art of deception through sexual cannibalism. It’s exactly how it sounds: the male is attracted to the female and tries to make some babies, but instead ends up being devoured. Sexual cannibalism hardly seems like a good strategy for keeping the mantis population up, but some argue it’s merely females taking advantage of every scrap of food they can find… even if it’s a loving male.

False garden mantis (Pseudomantis albofimbriata). Image by Donald Hobern from Wikimedia Commons.
When male mantises encounter a female in the wild they only have one thing on the brain, while a female may be more interested in self-preservation. If she hasn’t encountered food for a few days she will be VERY hungry and not all that interested in mating; in many species of mantises it is known that female mantises will eat males, even while having sex! So how do female mantises attract males?

For most insects, females are able to attract males with pheromones, chemicals released from an individual that affect other individuals of the same species. For instance, females can emit pheromones that will be telling of their age, reproductive status, and body condition. Males are able to detect pheromones from great distances and these pheromones play a role in allowing a male to determine how attractive a female could be. Before any sexy time can begin, females have to show that they are open to male advances. Showing a male you’ve never met before that you’re interested can be a difficult task- so females typically emit pheromones that are known as honest signals. These signals accurately convey female interest in mating, as well as her reproductive status, age, and body condition. Because the majority of females are being honest, males don’t have to think twice about their mate’s intentions. This is where female deception comes into play. If a female takes advantage of the lack of male wariness, she could end up with an easy meal. This deception by the females is what scientists know as the Femme Fatale hypothesis. This hypothesis explains that female mantises are naturally selected to deceive male mantises, and exploit them as food. This idea hasn’t had much backing evidence until Dr. Kate Barry of Macquarie University in Sydney, Australia sought to test this hypothesis with the false garden mantis (Pseudomantis albofimbriata).

After considering the test subjects and how the mantises communicate, Kate expected one of three possible outcomes:

1. There will be no pattern between female hunger and male attraction (if female false garden mantises are not femme fatales and false garden mantis pheromones do not communicate feeding-related information).

2. The well-fed females will attract the most males, while hungry females will attract the fewest males (if female false garden mantises are not femme fatales and females are always honest about their quality and willingness to mate).

3. The hungriest females will attract the most males, while well-fed females will still attract some males (if female false garden mantises are femme fatales and females are dishonest about their quality and willingness to mate when they are hungry).

To test her expectations, Kate gathered juvenile mantises that were close to their adult forms to have many male and female mantises that have no previous mating experience. Once the mantises were adults, females were given different feeding regimens to have a range of hunger. Categories included Good (well-fed), Medium (slightly less fed), Poor (hungry), and Very Poor (very, very hungry). Adult mantises were housed in a circular cage that separated each female individually around the edge, while the males were kept in the center.

Diagram of cage experiment was conducted in. Image by Britta Bibbo.
To allow the males to smell the female pheromones, researchers separated males by special walls that the males could not see through, but could still detect the pheromones given off by a female. The number of males on a female’s side of the cage was used to measure how attractive her pheromones were to the males.

The results of this study concluded that pheromones produced by the females that were very hungry were the most attractive to males. Through deception, the hungriest females are seen as sexier than well-fed, healthy females that are willing to mate! This result is surprising; normally females that are well-fed are seen as “sexier” because they have more nutrients available to them, making them more fertile. Hungry females have fewer nutrients available to them, making them less fertile, and therefore not as “sexy”. These hungry female mantises are advertising themselves as well-fed, fertile, and ready to rock when really, they’re not. Simply put, these results show that males are being catfished, and then consumed. Whether hungry females are actively trying to deceive males or if it’s just coincidental still needs to be looked into, but for now, be thankful for a partner who will see you as more than just a piece of meat!

Literature Cited:

Barry, K. (2014). Sexual deception in a cannibalistic mating system? Testing the Femme Fatale hypothesis Proceedings of the Royal Society B: Biological Sciences, 282 (1800), 20141428-20141428 DOI: 10.1098/rspb.2014.1428

Tuesday, May 9, 2017

The Best Moms in the Animal Kingdom

Moms are really important to life on Earth, as evidenced by the fact that maternal care is fairly common across the animal kingdom. In most species, females produce fewer, larger, and costlier eggs than males do sperm. Therefore, it is usually beneficial to females to maximize the possible success of each one, sometimes by gestating them inside their own bodies (as mammals do), or incubating the eggs until they are ready to hatch (as birds do), or by providing prolonged protection, food and training until they are ready to take on the world for themselves. But there is still a lot of variation in how and how much each mother gives to her offspring. Here are some of the best moms in the animal kingdom:

1. The Endurance Prize goes to orangutans: Orangutan infants cling to their moms’ bellies non-stop for the first four months of their life and they continue to completely depend on their moms for the first two years for food and transport. Their moms will continue to carry them often until they are five and will sometimes continue to breastfeed them until they are eight! After that, the young still stay close to mom, learning from her and helping her until they are sometimes in their teens.

An orangutan mama and toddler. Photo by Mistvan at Wikimedia Commons.

2. The Provider Prize goes to the crab spider, Diaea ergandros: These crab spider moms create a brood chamber and nest out of eucalyptus leaves. They guard their eggs and then spiderlings, providing protection and prey for food. These moms also make extra eggs, just for their babies to eat, and finally, they give themselves… quite literally! The babies eat their mothers completely in a rare behavior called matriphagy.


3. The Pregnancy Prize goes to elephants: Elephants are pregnant for about 22 months… nearly two years! And a baby elephant is not light to carry around… by the time it is born, it will weigh nearly 250 pounds! Just the thought of it makes me uncomfortable. So why would elephant moms need to gestate their young for such an incredibly long time? It is thought that the long gestation is needed for the proper development of their brains, so they are born with the complex cognitive and social skills needed to survive in their herd.

An African elephant family plays in the hot sun. Photo by Bernard Dupont at Wikimedia Commons.

4. The Brooding Prize goes to a deep-sea octopus: Two years is a very long time to carry a developing baby inside your body, but some animals care for their developing empryos ouside of their bodies with a behavior called brooding. Although brooding may sound easier than pregnancy, it is not for the faint of heart. A deep-sea octopus was observed brooding her eggs in the Monterey Submarine Canyon off central California for 53 months… That is nearly 4 and a half years! And that whole time she did not eat, but instead guarded and aerated the water around her precious eggs.

A deep-sea octopus. Photo by NOAA at Wikimedia Commons.

5. The Multi-Generational Prize goes to humans: Many human moms are not only good mothers, but also good grandmothers. Grandparenting is extremely rare in the animal kingdom (the first documented case of grandparenting in non-humans was as recent as 2008) and human females excel at it. They provide care, advice, resources, lessons and hugs to increase the success of their offspring and grand-offspring… It’s amazing other species haven’t picked up on this amazing secret yet!

The best moms in the animal kingdom. Photos by Sarah Jane Alger.

Tuesday, May 2, 2017

Caught in My Web: Ants Teach Us That Societal Cooperation is Possible

Image by Luc Viatour at Wikimedia Commons.
Societies are made up of lots of individuals, which each have different needs, perspectives, strengths and weaknesses. Cooperating with many individuals may have great benefits, but also poses giant challenges, even for a species as bright as our own. Humble ants may have some useful insight for us - They are masters of cooperation. So for this edition of Caught in My Web, we observe the inspirational societal cooperation of ants.

1. At Inspiring Science, Sedeer el-Showk explains how ants coordinate their foraging expeditions to maximize efficiency, despite the fact that they don't have a leader telling them what to do, when to do it and how to do it.

2. This video from Nature Communications shows ants working together to move a giant (to them) Cheerio.



3. Ben Hooper at UPI shares a video with us of a fire ant colony that responded to flooding in Louisiana by clinging together to form an ant life-raft.

And this video shows ants going even further, using their bodies to create a floating bridge for other foraging ants to cross.



4. Researchers at the Georgia Institute of Technology explain how ants form these rafts and demonstrate how they all stay dry.

5. At neuroecology, Adam J. Calhoun discusses how colony differences in foraging behavior can be passed down to new colonies. So maybe, those of us that figure this cooperation thing out can share the advice with the rest of us.

Tuesday, April 25, 2017

Can You Feel the Love Tonight? (A Guest Post)

A reposting of an article by Maggie Nannenhorn from March 14, 2016.

If you’re like me, you never truly realize how quiet winter is until all the sounds of spring come back in a chorus of celebration. Between the birds, crickets, and frogs, you can really hear the love in the air. So you can hear the love, but can you feel the love?

Wood frogs are known for their chorus of calls that sound like a duck laughing. Seriously, tell a duck a good knock-knock joke and that is what a male wood frog sounds like when trying to attract a mate. He makes the call by expanding his two vocal sacs, membranes of skin underneath the neck, forming a bubble-like appearance. When a female surfaces, drawn to the call, the male frog clasps onto her, causing her to lay her eggs. The male frog then externally fertilizes the eggs. This form of mating is termed amplexus. The use of the call in the reproduction ritual is well studied. However, it is possible the small ripple formed in the water from the expanding vocal sack is relaying information that influences the mating behavior of these frogs.


Male wood frog resting on the water surface. Image by Maggie Nannenhorn.
Male wood frog calling with vocal sac expanded.
Notice the ripple it creates in the water. Image by Maggie Nannenhorn.

In 2010, Gerlinde Höbel and Robb Kolodziej from the University of Wisconsin-Milwaukee conducted an experiment that explored the use of water surface waves in wood frog reproductive behavior. They hypothesized male wood frogs use ripples in the water to find female wood frogs to mate with, while female wood frogs use ripples in the water as indicators of harassing males.


Video of a wood frog calling by Maggie Nannenhorn.

Wood frogs have a very short mating period: only 1 to 3 days per year! This study occurred on April 1st - 2nd, which corresponded with the wood frogs’ natural mating period. The first component of the study was the observation of a pond containing more than 500 wood frogs in amplexus. Amplexus was determined by the presence of males clasping on to the backs of female frogs in the water. They learned males approach surface waves on the water and clasp onto the frog that caused the ripple. However, females move away from surface waves on the water and dive downward.

After preliminary observations, they developed an experiment to cause rippling of the water. The first experiment tested the effect of stimulation (dipping a wooden probe into the water) near male wood frogs. The males tested were randomly assigned to either a control group or an experimental group. The 34 males in the control group were simply observed, and the direction and pattern of movement was recorded. For the experimental group, a long wooden probe was dipped in and out of the water 25 cm away from a male frog for 10 seconds. The resulting ripple was meant to mimic a ripple caused by a female frog moving in the water. Based on the hypothesis, the male wood frogs should approach the ripple hoping to find a female to mate with. Of the 60 males in the experimental group, half were stimulated from the right and half were stimulated from the left. A circle diagram (depicted below) was used to map the direction the males moved.


video
Video of a wood frog approaching ripples by Gerlinde Höbel.


This figure shows: a) the control group and b) the experimental group.
A circle diagram representing the reproductively driven movement direction
of wood frogs (Lithobates sylvaticus) in a laboratory pool as a result of
stimulated surface waves on both the left and right sides.
Figure from: Höbel, G., & Kolodziej, R. C. (2013). Behaviour, 150(5), 471-483.

The females are difficult to observe in the field since they prefer to stay beneath the surface. So, the researchers set up a tank to test 4 breeding pairs of wood frogs. They tested the females both while in amplexus and while alone. They dipped wooden probes into the water to stimulate the females on both the left and the right side in turn. Their positions and directions were also recorded using a circle diagram.

So, what did they find? It turns out, their predictions were correct! The males would approach the ripple caused by the probing. This is likely because the ripple may indicate a competing male they want to drive away or a female they want to mate with. The females moved away from the ripples by either swimming away or diving underneath the water surface. This may reduce the amount of harassment they receive from males. If a female becomes the center of attention for too many males, she may drown from the weight of them all attempting to grab her. Besides, if a male is fit, he will likely be able to catch up to her and successfully mate with her despite her swimming away.

The mating calls and movement of the wood frogs affect the surface waves, and these waves are used to make sexual behavior choices. This spring, the chorus of love will still ring out through the reeds, and I encourage you to take a moment to stop and listen. When you’re stopped, take a moment to notice the waves of love bringing these wood frogs together. Hopefully this spring, we will all be feeling the love.



Reference:


Höbel, G., & Kolodziej, R. (2013). Wood frogs (Lithobates sylvaticus) use water surface waves in their reproductive behaviour Behaviour, 1-13 DOI: 10.1163/1568539X-00003062