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

Tuesday, April 18, 2017

What to Do If You Find Orphaned Wildlife

A reposting of an article from April 11, 2016.

A nest of baby cottontails waiting for sunset when their
mom will return. Image by Jhansonxi at Wikimedia.
Spring is finally in the air, and with Spring come babies! Finding baby animals in the wild is thrilling, but also concerning. Does this animal need your help? Where is its mom? What do you do?

Whenever possible, baby animals will do best when we leave them in the care of their mom. Even a well-meaning human is seen by a wild animal as a threat. Our interactions with them cause them extreme stress that can cause serious health problems and even death. Furthermore, if we take a baby animal home, it will not be able to learn its species-specific behaviors and skills and it can lose its natural and healthy fear of humans. It is also very hard to meet the specialized dietary needs of a wild animal in a captive setting. Taking a wild animal home can cause problems for us as well: many carry diseases that can be transmitted to our pets or even ourselves. And most wild animals are protected by state and federal laws that prohibit unlicensed citizens from possessing or raising them.

Luckily, most baby animals that seem alone actually have a mom that is not far away, either looking for food to feed herself and her babies or simply hiding from you. For example, rabbit mothers actively avoid their nests most of the time so as to not attract predators to the nest. Cottontail moms visit their babies only briefly at dawn and dusk for quick feedings. If you find a bunny nest, you can test to see if the mom is visiting by placing a few blades of grass or thin twigs in an X-shape over the babies. If you come back the next day and the pattern has been disturbed, then their mom is still caring for them and you should leave them be.

Many animal moms are prevented from taking care of their young when concerned people are hovering. Deer moms, for example, also actively avoid their babies (called fawns) so as to not attract predators to it. They generally return to nurse the fawns every few hours, but they won’t return to nurse if people or pets are around. If you find a fawn and it is not wandering and crying non-stop all day, then leave it alone so its mom will come back.

A red fox mom and baby. Photo by Nicke at Wikimedia.

Even if you find a baby all by itself in the open, the best course of action is often still to leave it alone. Many mammal moms, like squirrels, raccoons, mice, rats, foxes, and coyotes, will retrieve their young if they fall out of their nest or wander away from their den. Although it is a myth that most animal moms will abandon their babies if you get your smell on them, your odor can attract predators. It is best not to touch wildlife babies if you can avoid it.

Awww... as tempting as it is to pick up an adorable baby skunk, don't do it
unless you are a trained and licensed wildlife rehabilitator (like this woman is).
Image by AnimalPhotos at Wikimedia.

So when should you get involved? If an animal is in a dangerous location (like a busy street), then it may need to be moved. You can slowly, quietly and gently try to guide a mobile baby animal away from hazards and to a safer location. If the animal is not yet mobile, in most cases, you can use clean gloves to pick up the animal and move it to a safer location, placing it as close as possible to where you found it.

If you know that the mom is dead or has been relocated, then you are dealing with a truly orphaned baby animal. Likewise, if an animal has been attacked (or brought to you by your “helpful” cat), or is bleeding, injured, wet and emaciated, weak, infested with parasites, or has diarrhea, then it may need medical attention. In these cases, contact a licensed wildlife rehabilitator. Wildlife rehabilitators have been trained and have the necessary equipment to temporarily care for and treat injured, sick and orphaned wild animals so they can be released back into the wild. If you can’t find a wildlife rehabilitator, contact the Department of Natural Resources, a state wildlife agency, animal shelter, humane society, animal control agency, nature center, or veterinarian. Ideally, they will come to pick up the animal themselves. If they can’t, then they should give you detailed instructions for your situation on how to catch and transport the animal.

For more information, check here:

The Humane Society of the United States

The Wisconsin Department of Natural Resources

The Virginia Department of Game and Inland Fisheries

Tuesday, April 11, 2017

Risking Limb for Life? (A Guest Post)

By Matthew Whitley

Imagine you are walking alone in parking lot, when suddenly somebody grabs you by the arm and flashes a knife, demanding your money. Do you A) scream for help, B) try to wrestle the knife away, or C) remove your arm from your shoulder and make a break for it? Disarming your assailant may seem preferable to dis-arming yourself, but for a lizard option C is a likely response.

A lizard tail left behind. Image by Metatron at Wikimedia Commons.

You likely have heard before that many lizards can break off their tail when trying to make an escape. This ability is called caudal autotomy; autotomy meaning the ability to shed a limb, and caudal simply being a fancy word for tail. Of course, losing a limb is no simple procedure, and lizards possess many specialized features to make caudal autotomy possible.

There are two main kinds of caudal autotomy in lizards: intervertebral and intravertebral. Intervertebral refers to when the tail breaks between vertebrae, and is considered the simpler and more primitive form. Intravertebral, on the other hand, involves some more complex features. The word intravertebral refers to fracture planes found in the middle of each vertebra in the middle of the lizard’s tail. At these fracture planes, the bone can easily snap in half. This snapping of bone is performed by the lizard itself—when its tail is caught, muscles surrounding the bone just above where its tail is held squeeze tight until the bone breaks. After the bone breaks, the rest of the tail follows: the skin stretches and breaks, muscles detach, any remaining tissue divides, and—POP—the tail falls off!

After snapping your arm off to run from an attacker, you would probably just bleed out in your retreat, but lizards have that covered. In their tails, lizards have sphincters (rings of muscle) along their arteries—vessels that normally carry blood to the tail. When the tail is detached, these sphincters tighten to prevent blood from gushing out. Additionally, their veins, which normally bring blood back from the tail, have valves that prevent blood from flowing backwards, similar to the valves in your heart. And while the lizard makes its escape, the dislocated tail jerks and twitches, which distracts the lizard’s assailant. The tail owes its spastic actions to fast, glycolytic muscles, a variety of muscle that can act quickly and with a lot of force, but wears out quickly.

After our reptilian friend has made its daring escape, it has a new problem—it has no tail. A lizard without its tail is at a disadvantage, just as you would be without your arm. Lizards rely on their tails for several functions, including movement, nutrient storage, and social and sexual behaviors. Fortunately, lizards that exercise caudal autotomy can actually re-grow their tails, a process which itself is highly complex. In lieu of a lengthy explanation of another amazing phenomenon, I’ll share this tidbit: to regain lost nutrients and help recover, some lizards have been known to go back and eat their lost tail! So when you tear off your arm to escape a mugger, don’t forget to return to the scene of the crime to self-cannibalize…or maybe just buy some pepper spray beforehand.


Here you can see that the lizard is caught by the tail, pops it off and runs away, and the tail is left twitching.

Works Cited

Bateman, P., & Fleming, P. (2009). To cut a long tail short: a review of lizard caudal autotomy studies carried out over the last 20 years Journal of Zoology, 277 (1), 1-14 DOI: 10.1111/j.1469-7998.2008.00484.x

Clause, A., & Capaldi, E. (2006). Caudal autotomy and regeneration in lizards Journal of Experimental Zoology Part A: Comparative Experimental Biology, 305A (12), 965-973 DOI: 10.1002/jez.a.346

Gilbert, E., Payne, S., & Vickaryous, M. (2013). The Anatomy and Histology of Caudal Autotomy and Regeneration in Lizards Physiological and Biochemical Zoology, 86 (6), 631-644 DOI: 10.1086/673889

Tuesday, April 4, 2017

Researchers Finally Ask: Does Your Cat Even Like To Be Around You?

This cat has had enough and is running away
from home. Photo by Danielle Menuey.
While dogs happily and obliviously boast the reputation of being “man’s best friend”, cats have a reputation of being antisocial, independent, and downright grumpy. But do cats really deserve that? Scientists finally decided to find out.

Kristyn Vitale Shreve and Monique Udell from Oregon State University and Lindsay Mehrkam from Monmouth University asked 25 pet cats and 25 shelter cats their preferences.

How do you ask a cat what it prefers, you ask? You run a preference test, of course! A preference test is an experiment in which you place two or more things at equal distances from a subject and then test which of those things the subject spends the most time with.

Researchers suggest that these are some happy cats. Photo by Courtney Magnuson.

The researchers wanted to know if cats preferred: (1) food, (2) toys, (3) social interactions with humans, or (4) interesting odors. The trouble with that, however, is that there are many different foods, toys, interactions, and odors to choose from. So first, the researchers tested each cats' preferences within each category.

Will work for food. Photo by Charity Juang.
For food, the researchers put a soft chicken-flavored treat, actual chicken, and tuna into and around three puzzle boxes (so the cats would have easy access to taste some of each food, but couldn’t quickly gobble it up) and measured where the cats spent their time over a 3-minute period. Most of the cats liked the tuna most, next followed by the chicken, and they liked the soft treat the least.

For toys, the researchers made a movement toy by attaching a Dancer 101 Cat Dancer Interactive Cat Toy to a board and placing a GoCat Da Bird Feather Toy on the end with clear fishing line that was moved by an experimenter who was hidden outside the room. They then offered the movement toy, a still GoCat Da Bird Feather Toy on a board and a fuzzy shaker-mouse and they measured which toys the cats interacted with over a 3-minute period. Most of the cats liked the movement toy most, and they didn’t have much of a preference between the other two toys.

To test for cat preferences for types of human interactions, the cat’s owner (if it was a pet cat) or a researcher (if it was a shelter cat) spent one minute talking to the cat, another minute petting the cat (or holding their hand out to offer petting), and another minute playing with the cat with the feather toy (or holding out the toy). Researchers measured what proportion of each minute the cat spent interacting with the human. The cats interacted most with the humans during the play condition, next followed by petting, and least of all talking.

To see what odors cats preferred, the researchers put out cloths embedded with the scent of a gerbil (a potential prey), another cat, or catnip. The cats overwhelmingly preferred the catnip.

The preference test. Image from Vitale Shreve et al. 2017.

Once the researchers figured out what each cat preferred in each category, they set up a four-way grid with their favorite food, toy, social interaction, and odor and let them spend the next three minutes any way they liked.

Although there was a lot of variation among cats, 50% of the cats most preferred the social interaction with the human... even over food! Interestingly, the pet cats (who interacted with their owners) were no different in this regard than the shelter cats (who interacted with a researcher). But 37% of the cats most preferred food (maybe you have one of these cats). 11% preferred toys over all else. Only 1 cat (a pet named Hallie) preferred odor… the catnip fiend!

So although cats all have their own personalities, most of them really do like people. And they especially like to play with people. And, it turns out, they even do better at this than dogs (most of whom prefer food over people, when it really comes down to it). So go play with your kitty and give her some tuna… she’ll love you for it.

And, yes. This means that even cats can be trained with human interaction and food:


...But maybe not this one:

Some cats need more work than others. Photo by Jen Bray.


Want to know more? Check this out:

Vitale Shreve, K., Mehrkam, L., & Udell, M. (2017). Social interaction, food, scent or toys? A formal assessment of domestic pet and shelter cat ( Felis silvestris catus ) preferences Behavioural Processes DOI: 10.1016/j.beproc.2017.03.016

Tuesday, March 28, 2017

Bottlenose Dolphins: The Ultimate Sea Bully? (A Guest Post)

By Kayla Fuller

Imagine this situation: you’ve brought your favorite lunch to work. Everyone is jealous of your food, continuously eyeing it up. A few coworkers, who have brought in disappointing lunches in comparison, approach and demand that you hand it over. After you refuse, they beat you until your body lies lifeless and they take your lunch anyway.

Woah, woah, woah… that took a dramatic turn!

Photo of a harbour porpoise, taken by AVampireTear (Wikimedia Commons)

But for harbour porpoises in the northeastern Atlantic, this fight for food has become a reality, and bottlenose dolphins are the suspected culprit. In 1996, Harry M. Ross (SAC Veterinary Services, U.K.) and Ben Wilson (University of Aberdeen, U.K.) documented fractured rib cages, damaged internal organs and joint dislocations of deceased harbour porpoises in the northeastern Atlantic. Why would bottlenose dolphins be causing such damage? Who could ever associate such a cute and cuddly creature with a horrific crime like this?

Photo of a bottlenose dolphin, taken by NASA (Wikimedia Commons)

Researchers Jérôme Spitz, Yann Rousseau, and Vincent Ridoux with the Center for Research on Marine Mammals: Institute for Coastal and Environmental Research at the University of La Rochelle in France become the judge and jury in this trial. Jérôme, Yann, and Vincent obtained 29 harbour porpoises and 25 bottlenose dolphins that had been beached and died in the Bay of Biscay (between Spain, France, and England). At the time of the study, more harbour porpoises were being found dead in the bay than in previous years. They hypothesized that bottlenose dolphins and harbour porpoises may have had similar enough diets to cause competition and violence between the two species.

Photo of a harbour porpoise that received injuries thought to be from a
bottlenose dolphin before death (circled), from Ross and Wilson (1996)

The researchers’ goal was to analyze stomach contents to directly see what each mammal was eating at the time of their death. To do this, Jérôme, Yann, and Vincent removed the stomachs from the harbour porpoise bodies and weighed them with all contents included. After weighing stomach casings separately, they calculated total weight inside of the animals’ stomachs. Then, they washed stomach contents through a filter to separate out larger matter. Now, if you have a weak stomach, this probably wouldn’t be the job for you. Jérôme, Yann, and Vincent separated food items within the stomachs into identifiable categories. It could sometimes be difficult to recognize whole animals in a stomach due to breakdown, so methods like pairing dismantled eyes or counting fish bones was necessary to identify them! This same process was repeated for bottlenose dolphin carcasses. From there, the scientists compared specimens for prey presence, abundance, mass, and size to see if there was overlap between diets of the harbour porpoises and bottlenose dolphins.

So what did they find? More food mass, a greater number of species, and a more diverse size range of prey was found in the stomachs of bottlenose dolphins in comparison to harbour porpoises. Although bottlenose dolphins have a habitat that includes more deep-ocean areas while harbor porpoises inhabit coastal surroundings, certain prey species were eaten by both. Since bottlenose dolphins are bigger and hunt in larger groups, they would logically be more dominant in a face-off over a common prey item. Why are they fighting more over the same foods? This shift could be a result of humans harvesting species from the ocean that are diet items for bottlenose dolphins. It could also be a result of warming ocean temperatures that could be changing the dwelling places of available food for bottlenose dolphins. This would explain why more habour porpoises are being attacked by these marine tyrants moving into shallower waters.

Poor porpoises, all they want to do is eat their lunch in peace. Who knows, maybe in the next few million years, we’ll see highly evolved harbour porpoises covered in spikes to ward off the dolphins. That’ll teach those bullies!


References:

Ross, H., & Wilson, B. (1996). Violent Interactions between Bottlenose Dolphins and Harbour Porpoises Proceedings of the Royal Society B: Biological Sciences, 263 (1368), 283-286 DOI: 10.1098/rspb.1996.0043

Spitz, J., Rousseau, Y., & Ridoux, V. (2006). Diet overlap between harbour porpoise and bottlenose dolphin: An argument in favour of interference competition for food? Estuarine, Coastal and Shelf Science, 70 (1-2), 259-270 DOI: 10.1016/j.ecss.2006.04.020

Tuesday, March 21, 2017

The Weirdest Animals on Earth: 12 Amazing Facts About Platypuses

What IS that? A photo by Stefan Kraft at Wikimedia Commons.
1. Platypuses are so strange, that when British scientists first encountered one, they thought it was a joke: A Governor of New South Wales, Australia, sent a platypus pelt and sketch to British scientists in 1798. Even in their first published scientific description of the species, biologists thought that this duck-beaked, beaver-bodied, web-footed specimen may be some Frankenstein-like creation stitched together as a hoax. But this is only the beginning of their oddities…

2. Platypuses are egg-laying mammals. Mammals are animals that have a backbone, are warm-blooded, and females produce milk for their young. Most females that nurse their young also carry their developing babies in their bodies and give birth to live young… But platypuses don’t play by those rules. Platypuses are monotremes, egg-laying mammals that include the platypus and four species of echidna. Most female mammals have two functional ovaries, but female platypuses, like most female birds, only have a functional left ovary. Once a year, a female platypus may produce a clutch of two or three small, leathery eggs (similar to reptile eggs), that develop in her uterus for 28 days. Because female platypuses don’t even have a vagina, when the eggs are ready, she lays them through her cloaca, an opening that serves for reproduction, peeing and pooping. (In fact, monotreme comes from the Greek for “one hole”). She then curls around them and incubates them for another 10 days until they hatch.



3. Platypuses sweat milk! Not only do female platypuses not have vaginas, they don’t have nipples either! Instead, lactating mothers ooze milk from pores in their skin, which pools in grooves on their bellies so the babies can lap it up. …And they’re not even embarrassed about it!

4. Adult platypuses are toothless. Baby platypuses (that is the actual technical term for them, by the way… not “puggles”, which would be way more fun) are born with teeth but they lose them around the time that they leave the breeding burrow. In their place are rigid-edged keratinized pads that they use as grinding plates. When they catch their prey (worms, bugs, shrimp, and even crayfish), they store it in their cheek pouches and carry it to the surface, where they use gravel to crush it in their toothless maw.

5. The platypus “duck bill” is a sensory organ used to detect electric fields. Muscles and neurons use electrical impulses to function, and these impulses can be detected by electroreceptors. Although common in shark and ray species, electroreception is rare in mammals, only having been discovered in monotremes and the Guiana dolphin. Platypuses have rows of around 40,000 electroreceptors on their highly sensitive bill, which they wave back and forth in the water, much like a hammerhead shark, to determine the location of their prey. It’s a good thing this sense is so sensitive, since they close their eyes, nose and ears every time they dive.



6. Platypuses don’t use their tails like beavers do. Whereas beavers use their large, flat, leathery tails for swimming and slapping the water to send signals, platypuses don’t use their tails for any of that. Platypuses have large, flat tails for storing fat in case of a food shortage. Unlike beaver tails, platypus tails are covered in fur, which the mothers use to snuggle with their incubating eggs.

A platypus ankle spur. Photo by E.Lonnon at Wikimedia Commons.
7. Male platypuses have venomous ankle spurs. Their venom is strong enough to kill small animals and to create excruciating pain in humans. Since only males have it and they produce more venom during the breeding season, we think its main function may be to compete for mates and breeding territories.

8. Platypuses are knuckle-walkers with a reptilian gait. Although they are well-built for swimming with their webbed feet and legs on the sides of their bodies, these traits make it quite awkward to get around on dry land. To walk, they pull in their webbing and walk on their knuckles, exposing their claws. Like reptiles and salamanders, platypuses flex their spines from side-to-side, supported by their sprawling legs.



9. Platypuses have unusually low body temperatures. As unusual as they are, platypuses are still mammals, which are defined, in part, by their ability to generate most of their own body heat with their metabolism. Platypuses do this as well, but whereas most mammals maintain body temperatures between 37-40 degrees C (99-104 degrees F), platypuses are happy with a body temperature of 32 degrees C (90 degrees F). This lower metabolism reduces the amount of calories they need to eat.

10. They have no stomach. Stomachs are specialized protein-digesting chambers of digestive tracts that contain protein-digesting enzymes and acids to activate them. Not all animals have them, but most carnivores do. The most common exceptions to this rule are fish… and platypuses. Why? We don’t know for sure, but many of these animals consume diets high in calcium carbonate, which is a natural antacid. If their own diet would constantly neutralize their stomach acid, then the stomach really isn’t going to do them any good anyway.

11. They have 10 sex chromosomes! Most mammals have two sex chromosomes, one from each parent. An individual that has two X chromosomes is usually female and an individual that has one X and one Y chromosome is usually male. Thus, female mammals pass along an X chromosome to each offspring and males can pass along an X or a Y. But platypuses are not content to be normal in any way…They have 10 sex chromosomes: 5 from mom and 5 from dad. All 5 chromosomes from mom are Xs, whereas a male sperm either contains 5 Xs or 5 Ys. Birds also have two sex chromosomes, but in birds, individuals with two of the same type are usually male and individuals with different chromosomes are usually female. Their system is called ZW, where the mammalian system is XY. The platypus X chromosome is more similar than the X chromosome of other mammals to the bird Z chromosome.

12. The platypus genome is as much of a hodgepodge as its body. Only 80% of the platypus’ genes are like other mammals. Some of their genes have only previously been found in birds, reptiles, fish, or amphibians.

To learn about more weird animals, go here.

References:

Scheich, H., Langner, G., Tidemann, C., Coles, R., & Guppy, A. (1986). Electroreception and electrolocation in platypus Nature, 319 (6052), 401-402 DOI: 10.1038/319401a0

Warren, W., Hillier, L., Marshall Graves, J., Birney, E., Ponting, C., Grützner, F., Belov, K., Miller, W., Clarke, L., Chinwalla, A., Yang, S., Heger, A., Locke, D., Miethke, P., Waters, P., Veyrunes, F., Fulton, L., Fulton, B., Graves, T., Wallis, J., Puente, X., López-Otín, C., Ordóñez, G., Eichler, E., Chen, L., Cheng, Z., Deakin, J., Alsop, A., Thompson, K., Kirby, P., Papenfuss, A., Wakefield, M., Olender, T., Lancet, D., Huttley, G., Smit, A., Pask, A., Temple-Smith, P., Batzer, M., Walker, J., Konkel, M., Harris, R., Whittington, C., Wong, E., Gemmell, N., Buschiazzo, E., Vargas Jentzsch, I., Merkel, A., Schmitz, J., Zemann, A., Churakov, G., Ole Kriegs, J., Brosius, J., Murchison, E., Sachidanandam, R., Smith, C., Hannon, G., Tsend-Ayush, E., McMillan, D., Attenborough, R., Rens, W., Ferguson-Smith, M., Lefèvre, C., Sharp, J., Nicholas, K., Ray, D., Kube, M., Reinhardt, R., Pringle, T., Taylor, J., Jones, R., Nixon, B., Dacheux, J., Niwa, H., Sekita, Y., Huang, X., Stark, A., Kheradpour, P., Kellis, M., Flicek, P., Chen, Y., Webber, C., Hardison, R., Nelson, J., Hallsworth-Pepin, K., Delehaunty, K., Markovic, C., Minx, P., Feng, Y., Kremitzki, C., Mitreva, M., Glasscock, J., Wylie, T., Wohldmann, P., Thiru, P., Nhan, M., Pohl, C., Smith, S., Hou, S., Renfree, M., Mardis, E., & Wilson, R. (2008). Genome analysis of the platypus reveals unique signatures of evolution Nature, 453 (7192), 175-183 DOI: 10.1038/nature06936

Tuesday, March 14, 2017

The Physiology of Your “Sense of Self”

Quick! Name all of your senses!

Now, close your eyes and wave your arms over your head. Which of those senses are helping you know where your arms are in space?

The answer is the often-forgotten sense of proprioception. Proprioception (derived from the Latin for “sense of self”) is an animal’s sense of its body’s position in space. We have several different specialized receptor cells that all detect a change in body position in different ways.

Grays muscle picture by Mikael Haggstrom
at Wikimedia Commons.
If you raise your arms over your head as if you are going to grab a pull-up bar, then some muscles in your back (like your trapezius muscles), shoulders (like your deltoids and rotator cuff muscles), and arms (like your triceps) will contract. Muscles are all connected with tendons to the bones they pull on. When a muscle contracts, its tendons are stretched. Specialized proprioceptor cells called Golgi tendon organs merge with tendons and detect when their corresponding muscle is being stretched. Together, they inform the brain about muscle tension in muscles all across the body.

Grays muscle picture by Mikael Haggstrom
at Wikimedia Commons.

However, while some muscles will contract during your movement, other muscles in your chest (like your pecs) and arms (like your biceps) will stretch. Each muscle contains muscle spindles, another kind of specialized proprioceptor cell. Muscle spindles are wrapped around individual muscle fibers within the muscles. They send signals to the brain to let it know when the muscle is stretched and by how much.

Joint receptors are specialized proprioceptor cells located between bones in the capsular tissue of joints. When the angle of a joint changes, the bones and tissues put pressure on the joint receptor, causing it to send a signal to the brain. Your brain collects information from all of your Golgi tendon organs, muscle spindles and joint receptors to know the angle of each joint and the tension and length of each muscle in your body, and thus, your body’s position in space.

gif by Extremistpullup at Wikimedia Commons.
Some animals, and some individuals, are better at this than others. This guy should be pretty proud of his proprioceptive abilities (and strength). But then again, let’s see him try this: