Michael J. Ryan: A Taste for the Beautiful

Darwin developed the theory of sexual selection to explain why the animal world abounds in stunning beauty, from the brilliant colors of butterflies and fishes to the songs of birds and frogs. He argued that animals have “a taste for the beautiful” that drives their potential mates to evolve features that make them more sexually attractive and reproductively successful. But if Darwin explained why sexual beauty evolved in animals, he struggled to understand how. In A Taste for the Beautiful, Michael Ryan, one of the world’s leading authorities on animal behavior, tells the remarkable story of how he and other scientists have taken up where Darwin left off and transformed our understanding of sexual selection, shedding new light on human behavior in the process. Vividly written and filled with fascinating stories, A Taste for the Beautiful will change how you think about beauty and attraction. Read on to learn more about the evolution of beauty, why the sight of a peacock’s tail made Darwin sick, and why males tend to be the more “beautiful” in the animal kingdom.

What made you interested in the evolution of beauty?

For my Masters degree I was studying how male bullfrog set up and defend territories. They have a pretty imposing call that has been described as ‘jug-a-rum;’ it is used to repel neighboring males and to attract females. In those days it was thought that animal sexual displays functioned only to identify the species of the signaler. For example, in the pond where I worked you could easily tell the difference between bullfrogs, leopard frogs, green frogs, and spring peepers by listening to their calls. Females do the same so they can end up mating with the correct species. Variation among the calls within a species was thought of to be just noise, random variation that had little meaning to the females.

But sitting in this swamp night after night I was able to tell individual bullfrogs apart from one another and got used to seeing the same males with the loudest deepest calls in the same parts of the pond. I began to wonder that if I could hear these differences could the female bullfrogs, and could females decide who to mate with based on the male’s call? And also, if some calls sounded more beautiful to me, did female frogs share with me the same aesthetic?

I never got to answer these questions with the bullfrogs but I decided to pursue this general question when I started at Cornell University to work on my PhD degree.

Why did Darwin say that the sight of the peacock’s tail, an iconic example of sexual beauty, made him sick?

Darwin suffered all kinds of physical maladies, some probably brought on by his contraction of Chagas disease during his voyage on the Beagle. But this malady induced by the peacock’s tail probably resulted from cognitive dissonance. He had formulated a theory, natural selection, in which he was able to explain how animals evolve adaptations for survival. Alfred Russel Wallace developed a very similar theory. All seemed right with the world, at least for a while.

But then Darwin pointed out that many animal traits seem to hinder rather than promote survival. These included bright plumage and complex song in birds, flashing of fireflies, male fishes with swords, and of course the peacock with its magnificently long tail. All of these traits presented challenges to his theory of natural selection and the general idea of survival of the fittest. These sexy traits are ubiquitous throughout the animal kingdom but seem to harm rather than promote survival.

Sexual selection is Darwin’s theory that predicts the evolution of sexual beauty. How is this different from Darwin’s theory of natural selection?

The big difference between these two theories is that one focuses on survivorship while the other focuses on mating success. Both are important for promoting evolution, the disproportionate passage of genes from one generation to the next. An animal that survives for a long period of time but never reproduces is in a sense genetically dead. Animals that are extremely attractive but do not live long enough to reproduce also are at a genetic dead-end. It is the proper mix of survivorship and attractiveness that is most favored by selection. But the important point to realize is that natural selection and sexual selection are often opposed to one another; natural selection for example, favoring shorter tails in peacocks and sexual selection favoring longer tails. What the bird ends up with is a compromise between these two opposing selection forces.

In most of evolutionary biology the emphasis is still more on survival than mating success. But sometimes I think that surviving is just nature’s clever trick to keep individuals around long enough so that they can reproduce.

Why is it that in many animals the males are the more beautiful sex?

In most animals there are many differences between males and females. But what is the defining character? What makes a male a male and a female a female? It is not the way they act, the way they look, the way they behave. It is not even defined by the individual’s sex organs, penis versus vagina in many types of animals.

The defining characteristic of the sexes is gamete size. Males have many small gametes and females have fewer large gametes.  The maximum number of offspring that an animal can sire will be limited by the number of gametes. Therefore, males could potentially father many more offspring than a female could mother.

But of course males need females to reproduce. So this sets up competition where the many gametes of the males are competing to hook up with the fewer gametes of the females. Thus in many species males are under selection to mate often, they will never run out of gametes, while females are under selection to mate carefully and make good use of the fewer gametes they have. Thus males are competing for females, either through direct combat or by making themselves attractive to females, and females decide which males get to mate. The latter is the topic of this book.

Why is sexual beauty so dangerous?

The first step in communication is being noticed, standing out against the background. This is true whether animals communicate with sound, vision, or smells. It is especially true for sexual communication. The bind that males face is they need to make themselves conspicuous to females but their communication channel is not private, it is open to exploitation by eavesdroppers. These eavesdroppers can make a quick meal out of a sexually advertising male. One famous example, described in this book, involves the túngara frog and its nemesis, the frog-eating bat. Male túngara frogs add syllables, chucks, to their calls to increase their attractiveness to females. But it also makes them more attractive to bats, so when these males become more attractive they also become more likely to become a meal rather than a mate.

The túngara frog is only one example of the survival cost of attractive traits. When crickets call, for example, they can attract a parasitic fly. The fly lands on the calling male and her larvae crawl off of her onto the calling cricket. The larvae then burrow deep inside the cricket where they will develop. As they develop they eat the male from the inside out, and their first meal is the male’s singing muscle. This mutes the male so he will not attract other flies who would deposit their larvae on the male who would then become competitors.

Another cost of being attractive is tied up with the immune system. Many of the elaborate sexual traits of males develop in response to high levels of testosterone. Testosterone can have a negative effect on the immune system. So as males experience higher testosterone levels that might produce more attractive ornaments, but these males are paying the cost with their ability to resist disease.

How did you come to discover that frog eating bats are attracted to the calls of túngara frogs?

The credit for this initial discovery goes to Merlin Tuttle. Merlin is a well-known bat biologist and he was on BCI the year before I was. He captured a bat with a frog in its mouth. Merlin wondered how common this behavior was and whether the bats could hear the calls of the frogs and use those calls to find the frogs.

When Stan Rand and I discovered that túngara frogs become more attractive when they add chucks to their calls, we wondered why they didn’t produce chucks all the time. We were both convinced that there were some cost of producing chucks and we both thought it was likely the ultimate cost imposed by a predator.

Merlin contacted Stan about collaborating on research with the frog-eating bat and frog calls, and Stan then introduced Merlin to me. The rest is history as this research has blossomed into a major research program for a number of people.

Is beauty really in the eye of the beholder?

Yes, but it is also in the ears, the noses, the toes and any other sense organ recruited to check out potential mates. All of these sense organs forward information to the brain where judgements about beauty are made. So it is more accurate to say beauty is in the brain of the beholder. It might be true that the brain is our most important sex organ, but the brain has other things on its mind besides sex. It evolves under selection to perform a number of functions, and adaptations in one function can lead to unintended consequences for another function. For example, studies of some fish show that the color sensitivity of the eyes evolves to facilitate the fish’s ability to find its prey. Once this happens though, males evolve courtship colors to which their females’ eyes are particularly sensitive. This is called sensory exploitation.

A corollary of ‘beauty is in the brain of the beholder’ is that choosers, usually females, define what is beautiful. Females are not under selection to find out which males are attractive, by determining which males are attractive. They are in the driver’s seat when it comes to the evolution of beauty.

What is sensory exploitation?

We have probably all envisioned the perfect sexual partner. And in many cases those visions do not exist in reality. In a sense, the same might be true in animals. Females can have preferences for traits that do not exist. Or at least do not yet exist. When males evolve traits that elicit these otherwise hidden preferences this is called sensory exploitation. We can think of the evolution of sexual beauty as evolutionary attempts to probe the ‘preference landscape’ of the female. When a trait matches one of these previously unexpressed preferences, the male trait is immediately favored by sexual selection because it increases his mating success.

A good example of this occurs in a fish called the swordtail. In these fishes males have sword-like appendages protruding from their tails. Female swordtails prefer males with swords to those without swords, and males with longer swords to males with shorter swords. Swordtails are related to platyfish, the sword of swordtails evolved after the platyfish and swordtails split off from one another thousands of years ago. But when researchers attach a plastic sword to a male platyfish he becomes more attractive to female platyfish. These females have never seen a sworded male but they have a preference for that trait nonetheless. Thus it appears that when the first male swordtail evolved a sword the females already had a preference for this trait.

Do the girls really get prettier at closing time, as Mickey Gilly once sang?

They sure do, and so do the boys. A study showed that both men and women in a bar perceive members of the opposite sex as more attractive as closing time approaches. This classic study was repeated in Australia where they measured blood alcohol levels and showed that the ‘closing time’ effect was not only due to drinking but to the closing time of the bar.

The interpretation is of these results is that if an individual wants to go home with a member of the opposite sex but none of the individuals meet her or his expectations of beauty, the individual has two choices. They can lower their standards of beauty or they can deceive themselves and perceive the same individuals as more attractive. They seem to do the latter.

Although we do not know what goes on in an animal’s head, they show a similar pattern of behavior. Guppies and roaches are much more permissive in accepting otherwise unattractive mates as they get closer to the ultimate closing time, the end of their lives. In a similar example, early in the night female túngara frogs will reject certain calls that are usually unattractive, but later in the night when females become desperate to find a mate they become more than willing to be attracted to these same calls.  It is also noteworthy that middle-aged women think about sex more and have sex more often than do younger women.

Deception seems to be widespread in human courtship. What about animals?

Males have a number of tricks to deceive females for the purpose of mating. One example involves moths in which males make clicking sounds to court females. When males string together these clicks in rapid succession it sounds like the ‘feeding buzz’ of a bat, the sound a bat makes as it zeros in on its prey. At least this is what the female moths think. When they hear these clicks they freeze and the male moth is then able to mount the female and mate with her with little resistance as she appears to be scared to death, not of the male moth but of what she thinks is a bat homing in on her for the kill.

Other animals imitate food to drive female’s attention. Male mites beat their legs on the water surface imitating vibrations caused by copepods, the main source of food for the water mites. When females approach the source of these were vibrations they find a potential mate rather than a potential meal.

What about peer pressure? We know this plays a role in human in interactions, and the influence our perceptions of beauty? What about animals, can they be subjected to peer pressure?

Suppose a woman looks at my picture and is told rate my attractiveness on the scale of 1 to 10. Another woman is asked to do the same but in this picture I am standing next to an attractive woman. Almost certainly I will get a higher score the second time; my attractiveness increases although nothing about my looks have changed, only that I was consorting with a good-looking person.  This is referred to as mate choice and it is widespread in the animal kingdom.

Mate choice copying was first experimentally demonstrated in guppies. Female guppies prefer males who have more orange over those who have less orange. In a classic experiment, females were given a choice between a more than a less colorful male. They preferred the more colorful male and then were returned to the center of the tank for another experiment. In this instance they saw the less colorful and less preferred male courting a female. That female was removed and the test female was tested for her preference for the same two males once again. Now the female changes her preference and prefers what previously had been the less preferred male. She too seems to be employing mate choice copying.

Many animals learn by observing others. Mate choice copying seems to be a type of observational learning that is common in many animals in many domains. It might suggest that we be careful with whom we hang out.

What is the link between sexual attraction in animals and pornography in humans?

Animal sexual beauty is often characterized by being extreme: long tails, complex songs, brilliant colors, and outrageous dances. The same is often true of sexual beauty in humans. Female supermodels, for example, tend to be much longer and thinner than most other women in the population, male supermodels are super-buff—hardly normal. Furthermore, in animals we can create sexual traits that are more extreme than what exists in males of the population, and in experiments females often prefer these artificially exaggerated traits, such as: even longer tales, more complex songs, and more brilliant colors than exhibited by their own males. These are called supernormal stimuli. Pornography also creates supernormal stimuli not only in showcasing individuals with extreme traits but also in creating social settings that hardly exist in most societies, this manufactured social setting is sometimes referred to as Pornotopia.

RyanMichael J. Ryan is the Clark Hubbs Regents Professor in Zoology at the University of Texas and a Senior Research Associate at the Smithsonian Tropical Research Institute in Panama. He is a leading researcher in the fields of sexual selection, mate choice, and animal communication. He lives in Austin, Texas.

 

Kyle Harper: How climate change and disease helped the fall of Rome

HarperAt some time or another, every historian of Rome has been asked to say where we are, today, on Rome’s cycle of decline. Historians might squirm at such attempts to use the past but, even if history does not repeat itself, nor come packaged into moral lessons, it can deepen our sense of what it means to be human and how fragile our societies are.

In the middle of the second century, the Romans controlled a huge, geographically diverse part of the globe, from northern Britain to the edges of the Sahara, from the Atlantic to Mesopotamia. The generally prosperous population peaked at 75 million. Eventually, all free inhabitants of the empire came to enjoy the rights of Roman citizenship. Little wonder that the 18th-century English historian Edward Gibbon judged this age the ‘most happy’ in the history of our species – yet today we are more likely to see the advance of Roman civilisation as unwittingly planting the seeds of its own demise.

Five centuries later, the Roman empire was a small Byzantine rump-state controlled from Constantinople, its near-eastern provinces lost to Islamic invasions, its western lands covered by a patchwork of Germanic kingdoms. Trade receded, cities shrank, and technological advance halted. Despite the cultural vitality and spiritual legacy of these centuries, this period was marked by a declining population, political fragmentation, and lower levels of material complexity. When the historian Ian Morris at Stanford University created a universal social-development index, the fall of Rome emerged as the greatest setback in the history of human civilisation.

Explanations for a phenomenon of this magnitude abound: in 1984, the German classicist Alexander Demandt catalogued more than 200 hypotheses. Most scholars have looked to the internal political dynamics of the imperial system or the shifting geopolitical context of an empire whose neighbours gradually caught up in the sophistication of their military and political technologies. But new evidence has started to unveil the crucial role played by changes in the natural environment. The paradoxes of social development, and the inherent unpredictability of nature, worked in concert to bring about Rome’s demise.

Climate change did not begin with the exhaust fumes of industrialisation, but has been a permanent feature of human existence. Orbital mechanics (small variations in the tilt, spin and eccentricity of the Earth’s orbit) and solar cycles alter the amount and distribution of energy received from the Sun. And volcanic eruptions spew reflective sulphates into the atmosphere, sometimes with long-reaching effects. Modern, anthropogenic climate change is so perilous because it is happening quickly and in conjunction with so many other irreversible changes in the Earth’s biosphere. But climate change per se is nothing new.

The need to understand the natural context of modern climate change has been an unmitigated boon for historians. Earth scientists have scoured the planet for paleoclimate proxies, natural archives of the past environment. The effort to put climate change in the foreground of Roman history is motivated both by troves of new data and a heightened sensitivity to the importance of the physical environment. It turns out that climate had a major role in the rise and fall of Roman civilisation. The empire-builders benefitted from impeccable timing: the characteristic warm, wet and stable weather was conducive to economic productivity in an agrarian society. The benefits of economic growth supported the political and social bargains by which the Roman empire controlled its vast territory. The favourable climate, in ways subtle and profound, was baked into the empire’s innermost structure.

The end of this lucky climate regime did not immediately, or in any simple deterministic sense, spell the doom of Rome. Rather, a less favourable climate undermined its power just when the empire was imperilled by more dangerous enemies – Germans, Persians – from without. Climate instability peaked in the sixth century, during the reign of Justinian. Work by dendro-chronologists and ice-core experts points to an enormous spasm of volcanic activity in the 530s and 540s CE, unlike anything else in the past few thousand years. This violent sequence of eruptions triggered what is now called the ‘Late Antique Little Ice Age’, when much colder temperatures endured for at least 150 years. This phase of climate deterioration had decisive effects in Rome’s unravelling. It was also intimately linked to a catastrophe of even greater moment: the outbreak of the first pandemic of bubonic plague.

Disruptions in the biological environment were even more consequential to Rome’s destiny. For all the empire’s precocious advances, life expectancies ranged in the mid-20s, with infectious diseases the leading cause of death. But the array of diseases that preyed upon Romans was not static and, here too, new sensibilities and technologies are radically changing the way we understand the dynamics of evolutionary history – both for our own species, and for our microbial allies and adversaries.

The highly urbanised, highly interconnected Roman empire was a boon to its microbial inhabitants. Humble gastro-enteric diseases such as Shigellosis and paratyphoid fevers spread via contamination of food and water, and flourished in densely packed cities. Where swamps were drained and highways laid, the potential of malaria was unlocked in its worst form – Plasmodium falciparum – a deadly mosquito-borne protozoon. The Romans also connected societies by land and by sea as never before, with the unintended consequence that germs moved as never before, too. Slow killers such as tuberculosis and leprosy enjoyed a heyday in the web of interconnected cities fostered by Roman development.

However, the decisive factor in Rome’s biological history was the arrival of new germs capable of causing pandemic events. The empire was rocked by three such intercontinental disease events. The Antonine plague coincided with the end of the optimal climate regime, and was probably the global debut of the smallpox virus. The empire recovered, but never regained its previous commanding dominance. Then, in the mid-third century, a mysterious affliction of unknown origin called the Plague of Cyprian sent the empire into a tailspin. Though it rebounded, the empire was profoundly altered – with a new kind of emperor, a new kind of money, a new kind of society, and soon a new religion known as Christianity. Most dramatically, in the sixth century a resurgent empire led by Justinian faced a pandemic of bubonic plague, a prelude to the medieval Black Death. The toll was unfathomable – maybe half the population was felled.

The plague of Justinian is a case study in the extraordinarily complex relationship between human and natural systems. The culprit, the Yersinia pestis bacterium, is not a particularly ancient nemesis; evolving just 4,000 years ago, almost certainly in central Asia, it was an evolutionary newborn when it caused the first plague pandemic. The disease is permanently present in colonies of social, burrowing rodents such as marmots or gerbils. However, the historic plague pandemics were colossal accidents, spillover events involving at least five different species: the bacterium, the reservoir rodent, the amplification host (the black rat, which lives close to humans), the fleas that spread the germ, and the people caught in the crossfire.

Genetic evidence suggests that the strain of Yersinia pestis that generated the plague of Justinian originated somewhere near western China. It first appeared on the southern shores of the Mediterranean and, in all likelihood, was smuggled in along the southern, seaborne trading networks that carried silk and spices to Roman consumers. It was an accident of early globalisation. Once the germ reached the seething colonies of commensal rodents, fattened on the empire’s giant stores of grain, the mortality was unstoppable.

The plague pandemic was an event of astonishing ecological complexity. It required purely chance conjunctions, especially if the initial outbreak beyond the reservoir rodents in central Asia was triggered by those massive volcanic eruptions in the years preceding it. It also involved the unintended consequences of the built human environment – such as the global trade networks that shuttled the germ onto Roman shores, or the proliferation of rats inside the empire. The pandemic baffles our distinctions between structure and chance, pattern and contingency. Therein lies one of the lessons of Rome. Humans shape nature – above all, the ecological conditions within which evolution plays out. But nature remains blind to our intentions, and other organisms and ecosystems do not obey our rules. Climate change and disease evolution have been the wild cards of human history.

Our world now is very different from ancient Rome. We have public health, germ theory and antibiotic pharmaceuticals. We will not be as helpless as the Romans, if we are wise enough to recognise the grave threats looming around us, and to use the tools at our disposal to mitigate them. But the centrality of nature in Rome’s fall gives us reason to reconsider the power of the physical and biological environment to tilt the fortunes of human societies. Perhaps we could come to see the Romans not so much as an ancient civilisation, standing across an impassable divide from our modern age, but rather as the makers of our world today. They built a civilisation where global networks, emerging infectious diseases and ecological instability were decisive forces in the fate of human societies. The Romans, too, thought they had the upper hand over the fickle and furious power of the natural environment. History warns us: they were wrong.Aeon counter – do not remove

Kyle Harper is professor of classics and letters and senior vice president and provost at the University of Oklahoma. He is the author of The Fate of Rome, recently released, as well as Slavery in the Late Roman World, AD 275–425 and From Shame to Sin: The Christian Transformation of Sexual Morality in Late Antiquity. He lives in Norman, Oklahoma.

This article was originally published at Aeon and has been republished under Creative Commons.

Essential Reading in Natural History

Princeton University Press is excited to have a wide variety of excellent titles in natural history. From the Pacific Ocean, to horses, to moths, our books cover a range of topics both large and small. As summer winds down, take advantage of the last weeks of warm weather by bringing one of our handy guides out into the field to see if you can spot a rare butterfly or spider. To find your next read, check out this list of some of our favorite titles in natural history, and be sure to visit our website for further reading.

Britain’s Mammals by Dominic Couzens, Andy Swash, Robert Still, and Jon Dun is a comprehensive and beautifully designed photographic field guide to all the mammals recorded in the wild in Britain and Ireland in recent times.

Mammals

Horses of the World by Élise Rousseau, with illustrations by Yann Le Bris, is a beautifully illustrated and detailed guide to the world’s horses.

Horses

A Swift Guide to the Butterflies of North America, Second Edition, by Jeffrey Glassberg is a thoroughly revised edition of the most comprehensive and authoritative photographic field guide to North American butterflies.

Butterflies

Big Pacific by Rebecca Tansley is the companion book to PBS’s five-part mini series that breaks the boundaries between land and sea to present the Pacific Ocean and its inhabitants as you have never seen them before.

Pacific

Britain’s Spiders by Lawrence Bee, Geoff Oxford, and Helen Smith is a photographic guide to all 37 of the British families.

Spiders

The second edition of Garden Insects of North America by Whitney Cranshaw and David Shetlar is a revised and updated edition of the most comprehensive guide to common insects, mites, and other “bugs” found in the backyards and gardens of the United States and Canada.

Cranshaw

Last but not least, Mariposas Nocturnas is a stunning portrait of the nocturnal moths of Central and South America by famed American photographer Emmet Gowin.

Gowin

John Kricher on The New Neotropical Companion (revised & expanded)

The New Neotropical Companion by John Kricher is the completely revised and expanded edition of a book that has helped thousands of people to understand the complex ecology and natural history of the most species-rich area on Earth, the American tropics. Featuring stunning color photos throughout, it is a sweeping and cutting-edge account of tropical ecology that includes not only tropical rain forests but also other ecosystems such as cloud forests, rivers, savannas, and mountains. This is the only guide to the American tropics that is all-inclusive, encompassing the entire region’s ecology and the amazing relationships among species rather than focusing just on species identification.

What originally focused your interest in the Neotropics and why did you want to write about the region? 

JK: When I was early in my career in ecology and ornithology, way back in the 1970s, I longed to experience the tropics, to be in hot, steamy equatorial jungles, the ecosystems of the world that harbor the most species.  There was so much I wanted to see, especially bird species. It was really birds that got me there.  I wanted to see firsthand the various tropical birds, the antbirds, parrots, cotingas, trogons, toucans, etc.  To me, these were pure glamor birds, and so many of them.  Reading about them only intensified my need to go and see them firsthand.  So, I jumped on the first opportunity that came along to get myself passage into “the Torrid Zone.”

And what was that opportunity? 

JK: I met a man who was to become a long-time close friend, Fred Dodd.  Fred had just started a company called International Zoological Expeditions (IZE) and he was organizing trips to Belize for college classes.  I saw such a trip as my ideal way to get a foothold in the tropics.  And it worked!  My first tropical experience was to take a class of about 30 students from Wheaton College to Belize and Guatemala over semester break in January of 1979.  The unexpected and challenging experiences we had as we faced numerous logistical hurdles in this admittedly pioneering effort would, in themselves, make a pretty cool book.  But we did it, I loved it, and wanted more, much more.  When I meet my first Tropical Ecology students at alumnae gatherings they all want to relive memories of “the Belize trip.”  We tell the same stories over and over and never seem to tire of it.  Going to Belize, getting to the American tropics, was a watershed experience for me, transforming my career.

Why did you feel the need to write A Neotropical Companion and how did you choose that title? 

JK: It was hard to systematically organize information to present to students about the American tropics.  In the late 1970s information about the tropics was widely scattered and incomplete.  For example, there was no single book I could recommend to my students to prepare them for what would await them in the field.  At the same time, I read multiple journal articles on everything from tree diversity to army ant behavior and it was such cool stuff.  I loved telling the students my various “stories” gleaned from the ecological literature.  As I made more and more visits to Central and South American countries my own perspective was greatly enhanced so I could bring something to the table, so to speak, directly from personal experience.  My knowledge base grew in leaps and bounds and I kept expecting that any day a book would be published that would bring together what I was experiencing and enjoying.  It never was.  So, I thought I could adapt my course information into an introductory book. That was what spawned A Neotropical Companion.  The illustrations in the first edition, published in 1989, were by one of my tropical ecology students who adapted them from her field notebook kept when she took my tropical course in Belize.  As for the title, when Judith May, editor at Princeton University Press, read my manuscript she liked it and said, with enthusiasm, that she had “the perfect title” for the book.  It was Judith who gave it its name.

Your first edition was nicknamed “The Little Green Book.”  Did its popularity surprise you? 

JK: It did.  It was flattering that many folks told me they carried my little green book on various tropical trips and found it very informative and easy to read.  And it was indeed a little green book that conveniently fit in a pocket or backpack.  I knew I had barely scratched the surface with regard both to breadth and depth of information but I was very pleased and a bit surprised by the warm reception the book received.  And as I began making frequent trips to lowland Amazonia as well as Andean ecosystems I knew it was time to expand and revise the book.  The little green book needed to grow.  It did that with the publication of the second edition in 1997 and obtained what I consider its “full maturity,” a coming of age, in the present edition.  It is no longer green and no longer little but much more comprehensive and far better illustrated than its predecessors. This is the book I had always wanted to write.

What is the biggest thing that has changed with regard to visiting the American tropics since you first wrote your Little Green Book? 

JK: In the nearly 30 years since I published the first edition the American tropics has become much easier and more comfortable to visit.  Good tourist lodges were relatively few when I first visited the tropics and now they abound. Talented local guides skilled in finding wildlife take groups to see all manner of fantastic species such as Harpy Eagle, for example. There are now tours in which you are virtually assured of getting fine views of fully wild jaguars.  I wrote in the first edition about being very careful as to what you eat, where you go, and various health concerns.  I scaled that way back in my new edition because it is no longer necessary to include it.  A determined traveler may make trips virtually anywhere in the Neotropics and do so safely and in relative comfort, though some areas do remain rugged and challenging.  There are now even tours to Theodore Roosevelt’s famous “River of Doubt,” once considered a huge challenge to explorers.  This was unheard of when I began my travel to the tropics.

Are you still always being asked about encountering snakes and biting insects in the tropics?

JK: Indeed, I am.  And to be truthful, snakes, including many venomous species, are relatively common if not abundant in some tropical venues, though they are not necessarily easy to find unless one is skilled at searching for them.  It is important to be vigilant when on trails and walking around lodges and field stations, especially at night or after a rainfall.  Snakes may be out and about.  But very few encounters result in venomous snake bites.  I encourage people to experience snakes as interesting and beautiful animals and, as one would a lion on the Serengeti, make sure to maintain a respectful distance.  In Trinidad, my group encountered a huge bushmaster, the largest of the Neotropical venomous snakes.  It was crossing a road late at night and was caught in the headlights of our van.  We all saw it well and from a safe distance, a thrilling sight.  As for insects, I have rarely been very bothered by them, especially mosquitos, but if you travel in rainy season mosquitos may be locally abundant and highly annoying.  Visitors to the tropics must really beware of bees and wasps and even ants, some of which act aggressively if disturbed and may pack a powerful sting.  One ant is called the “bullet ant” because it bites you, holds on, and then stings you. The sting allegedly feels like you were hit with a bullet.

Now that The New Neotropical Companion is complete do you have any plans for further exploration of the Neotropics or are you satisfied that you have done all you set out to do?

JK: I continue to be strongly drawn to the American tropics.  I have very recently visited Honduras and Cuba.  I have plans for trips to numerous other Neotropical venues, from Guyana to Peru and Amazonia.  The wonder of the regional biodiversity has always compelled me to want to see more, go to new areas as well as revisit places I have come to know well, and just keep on learning.  No two visits to the tropics, even to a place where one has been repeatedly, are the same.  The more you go, the more you see.  So, I keep going.

John Kricher is professor of biology at Wheaton College. His many books include Tropical Ecology, The Balance of Nature: Ecology’s Enduring Myth, and Galápagos: A Natural History.

Peter Ungar: It’s not that your teeth are too big: your jaw is too small

UngarWe hold in our mouths the legacy of our evolution. We rarely consider just how amazing our teeth are. They break food without themselves being broken, up to millions of times over the course of a lifetime; and they do it built from the very same raw materials as the foods they are breaking. Nature is truly an inspired engineer.

But our teeth are, at the same time, really messed up. Think about it. Do you have impacted wisdom teeth? Are your lower front teeth crooked or out of line? Do your uppers jut out over your lowers? Nearly all of us have to say ‘yes’ to at least one of these questions, unless we’ve had dental work. It’s as if our teeth are too big to fit properly in our jaws, and there isn’t enough room in the back or front for them all. It just doesn’t make sense that such an otherwise well-designed system would be so ill-fitting.

Other animals tend to have perfectly aligned teeth. Our distant hominin ancestors did too; and so do the few remaining peoples today who live a traditional hunting and gathering lifestyle. I am a dental anthropologist at the University of Arkansas, and I work with the Hadza foragers of Africa’s great rift valley in Tanzania. The first thing you notice when you look into a Hadza mouth is that they’ve got a lot of teeth. Most have 20 back teeth, whereas the rest of us tend to have 16 erupted and working. Hadza also typically have a tip-to-tip bite between the upper and lower front teeth; and the edges of their lowers align to form a perfect, flawless arch. In other words, the sizes of Hadza teeth and jaws match perfectly. The same goes for our fossil forebears and for our nearest living relatives, the monkeys and apes.

So why don’t our teeth fit properly in the jaw? The short answer is not that our teeth are too large, but that our jaws are too small to fit them in. Let me explain. Human teeth are covered with a hard cap of enamel that forms from the inside out. The cells that make the cap move outward toward the eventual surface as the tooth forms, leaving a trail of enamel behind. If you’ve ever wondered why your teeth can’t grow or repair themselves when they break or develop cavities, it’s because the cells that make enamel die and are shed when a tooth erupts. So the sizes and shapes of our teeth are genetically pre-programmed. They cannot change in response to conditions in the mouth.

But the jaw is a different story. Its size depends both on genetics and environment; and it grows longer with heavy use, particularly during childhood, because of the way bone responds to stress. The evolutionary biologist Daniel Lieberman at Harvard University conducted an elegant study in 2004 on hyraxes fed soft, cooked foods and tough, raw foods. Higher chewing strains resulted in more growth in the bone that anchors the teeth. He showed that the ultimate length of a jaw depends on the stress put on it during chewing.

Selection for jaw length is based on the growth expected, given a hard or tough diet. In this way, diet determines how well jaw length matches tooth size. It is a fine balancing act, and our species has had 200,000 years to get it right. The problem for us is that, for most of that time, our ancestors didn’t feed their children the kind of mush we feed ours today. Our teeth don’t fit because they evolved instead to match the longer jaw that would develop in a more challenging strain environment. Ours are too short because we don’t give them the workout nature expects us to.

There’s plenty of evidence for this. The dental anthropologist Robert Corruccini at Southern Illinois University has seen the effects by comparing urban dwellers and rural peoples in and around the city of Chandigarh in north India – soft breads and mashed lentils on the one hand, coarse millet and tough vegetables on the other. He has also seen it from one generation to the next in the Pima peoples of Arizona, following the opening of a commercial food-processing facility on the reservation. Diet makes a huge difference. I remember asking my wife not to cut our daughters’ meat into such small pieces when they were young. ‘Let them chew,’ I begged. She replied that she’d rather pay for braces than have them choke. I lost that argument.

Crowded, crooked, misaligned and impacted teeth are huge problems that have clear aesthetic consequences, but can also affect chewing and lead to decay. Half us could benefit from orthodontic treatment. Those treatments often involve pulling out or carving down teeth to match tooth row with jaw length. But does this approach really make sense from an evolutionary perspective? Some clinicians think not. And one of my colleagues at Arkansas, the bioarchaeologist Jerry Rose, has joined forces with the local orthodontist Richard Roblee with this very question in mind. Their recommendation? That clinicians should focus more on growing jaws, especially for children. For adults, surgical options for stimulating bone growth are gaining momentum, too, and can lead to shorter treatment times.

As a final thought, tooth crowding isn’t the only problem that comes from a shorter jaw. Sleep apnea is another. A smaller mouth means less space for the tongue, so it can fall back more easily into the throat during sleep, potentially blocking the airway. It should come as no surprise that appliances and even surgery to pull the jaw forward are gaining traction in treating obstructive sleep apnea.

For better and for worse, we hold in our mouths the legacy of our evolution. We might be stuck with an oral environment that our ancestors never had to contend with, but recognising this can help us deal with it in better ways. Think about that the next time you smile and look in a mirror.

Evolution’s Bite: A Story of Teeth, Diet, and Human Origins by Peter Ungar is out now through Princeton University Press.Aeon counter – do not remove

Peter S. Ungar is Distinguished Professor and director of the Environmental Dynamics Program at the University of Arkansas. He is the author of Teeth: A Very Short Introduction and Mammal Teeth: Origin, Evolution, and Diversity and the editor of Evolution of the Human Diet: The Known, the Unknown, and the Unknowable. He lives in Fayetteville, Arkansas.

This article was originally published at Aeon and has been republished under Creative Commons.

Peter Ungar: It’s not that your teeth are too big: your jaw is too small

We hold in our mouths the legacy of our evolution. We rarely consider just how amazing our teeth are. They break food without themselves being broken, up to millions of times over the course of a lifetime; and they do it built from the very same raw materials as the foods they are breaking. Nature is truly an inspired engineer.

But our teeth are, at the same time, really messed up. Think about it. Do you have impacted wisdom teeth? Are your lower front teeth crooked or out of line? Do your uppers jut out over your lowers? Nearly all of us have to say ‘yes’ to at least one of these questions, unless we’ve had dental work. It’s as if our teeth are too big to fit properly in our jaws, and there isn’t enough room in the back or front for them all. It just doesn’t make sense that such an otherwise well-designed system would be so ill-fitting.

Other animals tend to have perfectly aligned teeth. Our distant hominin ancestors did too; and so do the few remaining peoples today who live a traditional hunting and gathering lifestyle. I am a dental anthropologist at the University of Arkansas, and I work with the Hadza foragers of Africa’s great rift valley in Tanzania. The first thing you notice when you look into a Hadza mouth is that they’ve got a lot of teeth. Most have 20 back teeth, whereas the rest of us tend to have 16 erupted and working. Hadza also typically have a tip-to-tip bite between the upper and lower front teeth; and the edges of their lowers align to form a perfect, flawless arch. In other words, the sizes of Hadza teeth and jaws match perfectly. The same goes for our fossil forebears and for our nearest living relatives, the monkeys and apes.

So why don’t our teeth fit properly in the jaw? The short answer is not that our teeth are too large, but that our jaws are too small to fit them in. Let me explain. Human teeth are covered with a hard cap of enamel that forms from the inside out. The cells that make the cap move outward toward the eventual surface as the tooth forms, leaving a trail of enamel behind. If you’ve ever wondered why your teeth can’t grow or repair themselves when they break or develop cavities, it’s because the cells that make enamel die and are shed when a tooth erupts. So the sizes and shapes of our teeth are genetically pre-programmed. They cannot change in response to conditions in the mouth.

But the jaw is a different story. Its size depends both on genetics and environment; and it grows longer with heavy use, particularly during childhood, because of the way bone responds to stress. The evolutionary biologist Daniel Lieberman at Harvard University conducted an elegant study in 2004 on hyraxes fed soft, cooked foods and tough, raw foods. Higher chewing strains resulted in more growth in the bone that anchors the teeth. He showed that the ultimate length of a jaw depends on the stress put on it during chewing.

Selection for jaw length is based on the growth expected, given a hard or tough diet. In this way, diet determines how well jaw length matches tooth size. It is a fine balancing act, and our species has had 200,000 years to get it right. The problem for us is that, for most of that time, our ancestors didn’t feed their children the kind of mush we feed ours today. Our teeth don’t fit because they evolved instead to match the longer jaw that would develop in a more challenging strain environment. Ours are too short because we don’t give them the workout nature expects us to.

There’s plenty of evidence for this. The dental anthropologist Robert Corruccini at Southern Illinois University has seen the effects by comparing urban dwellers and rural peoples in and around the city of Chandigarh in north India – soft breads and mashed lentils on the one hand, coarse millet and tough vegetables on the other. He has also seen it from one generation to the next in the Pima peoples of Arizona, following the opening of a commercial food-processing facility on the reservation. Diet makes a huge difference. I remember asking my wife not to cut our daughters’ meat into such small pieces when they were young. ‘Let them chew,’ I begged. She replied that she’d rather pay for braces than have them choke. I lost that argument.

Crowded, crooked, misaligned and impacted teeth are huge problems that have clear aesthetic consequences, but can also affect chewing and lead to decay. Half us could benefit from orthodontic treatment. Those treatments often involve pulling out or carving down teeth to match tooth row with jaw length. But does this approach really make sense from an evolutionary perspective? Some clinicians think not. And one of my colleagues at Arkansas, the bioarchaeologist Jerry Rose, has joined forces with the local orthodontist Richard Roblee with this very question in mind. Their recommendation? That clinicians should focus more on growing jaws, especially for children. For adults, surgical options for stimulating bone growth are gaining momentum, too, and can lead to shorter treatment times.

As a final thought, tooth crowding isn’t the only problem that comes from a shorter jaw. Sleep apnea is another. A smaller mouth means less space for the tongue, so it can fall back more easily into the throat during sleep, potentially blocking the airway. It should come as no surprise that appliances and even surgery to pull the jaw forward are gaining traction in treating obstructive sleep apnea.

For better and for worse, we hold in our mouths the legacy of our evolution. We might be stuck with an oral environment that our ancestors never had to contend with, but recognising this can help us deal with it in better ways. Think about that the next time you smile and look in a mirror.

Evolution’s Bite: A Story of Teeth, Diet, and Human Origins by Peter Ungar is out now through Princeton University Press.Aeon counter – do not remove

UngarPeter S. Ungar is Distinguished Professor and director of the Environmental Dynamics Program at the University of Arkansas. He is the author of Evolution’s Bite: A Story of Teeth, Diet, and Human Origins, Teeth: A Very Short Introduction and Mammal Teeth: Origin, Evolution, and Diversity and the editor of Evolution of the Human Diet: The Known, the Unknown, and the Unknowable. He lives in Fayetteville, Arkansas.

This article was originally published at Aeon and has been republished under Creative Commons.

Paul Strode: Teaching The Serengeti Rules

CarrollIn January of 2016 I was asked by Laura Bonetta at the Howard Hughes Medical Institute (HHMI) to write a teacher’s guide for the short film Some Animals Are More Equal than Others: Keystone Species and Trophic Cascades. At the same time, Molecular Biologist Sean B. Carroll, the HHMI Vice President of Science Education, was putting the finishing touches on his new book, The Serengeti Rules. To help expedite my research for writing the teacher’s guide for the short film, Laura sent me a pre-pub copy of the book and suggested I read Chapter Six: “Some Animals Are More Equal than Others.”

Instead of going straight to Chapter Six, I started reading from the beginning.

Before I was even halfway through the first chapter, I thought to myself, this book is going to change the way I teach. At the core of Carroll’s storytelling is the observation that everything is regulated, from molecules to megafauna. Indeed, for most of my career teaching biology I have kept my focus on Theodosius Dobzhansky’s argument that “nothing in biology makes sense except in the light of evolution.” But Carroll has now made it clear that nothing in biology also makes sense except in the light of regulation.

To make a long story short, I wrote the short film teachers guide with the help of Chapter Six in The Serengeti Rules and immediately followed that task by reviewing the book for The American Biology Teacher so that other teachers might benefit from reading the book. In my review, I argued that The Serengeti Rules “should be required reading for students in all fields of science, but especially those pursuing careers in biology education.” My review caught the attention of Carroll’s editor at Princeton University Press, Alison Kalett. Alison was curious to know if teachers like me that planned to use Carroll’s book to enhance their biology courses would find it useful if educational supplementary materials were made available… for free. Alison and I came up with a plan and I began to write.

The Serengeti Rules came out in March of 2016 and one of Carroll’s first public discussions about the book was at the annual Professional Development Conference of the National Association of Biology Teachers in Providence, Rhode Island. Several hundred teachers showed up to hear from Dr. Carroll and it was standing room only. As word got out that supplementary materials were being prepared for Carroll’s book, inquiries began to pop up on social media.

Carroll

The Educational Supplement was released in May and is a document that a teacher can use immediately in the classroom.

Carroll

The questions come in various styles and are designed to invoke classroom discussion, require students to synthesize and connect various biological concepts, get students to engage with ecological data from the published journal articles, and have students analyze and graph data that relate to what they are reading in The Serengeti Rules. For example, the question below relates to Chapter Four of The Serengeti Rules, “Fat, Feedback, and a Miracle Fungus.” The question can be used as a formative assessment question that marries real data with the nature of science and covers several components of the Advanced Placement and International Baccalaureate biology course content.

Carroll

Teachers have already begun planning to use The Serengeti Rules to enhance their courses and since the release of the supplement have expressed their gratitude that it is available and free!

Carroll

And of course, I have assigned The Serengeti Rules as summer reading for my 65 AP/IB biology students and I am looking forward to using the questions in the fall to incite discussion and enhance learning and understanding.

Thank you, Sean B. Carroll, for giving us The Serengeti Rules!

Bird Fact Friday – Why does the Toucan have such a large, colorful bill?

From page 273 in The New Neotropical Companion:

Photo by James Adams

Perhaps more than any other kind of bird, toucans symbolize the American tropics. With a prominent boat-shaped, colorful bill almost equal in length to the body, the toucan silhouette is instantly recognizable. Toucans’ seemingly oversize bills are actually lightweight. Colorful patterns adorn most ramphastid bills; they may possibly be used for signaling in mate selection. Recent studies on the Toco Toucan have demonstrated that the birds are able to radiate excess heat from their long, vascularized bills. In a paper by Glenn Tattersall and colleagues, the researchers conclude that the toucan bill is “relative to its size, one of the largest thermal windows in the animal kingdom, rivaling elephants’ ears in its ability to radiate body heat.”

Toko Toucan. Photo by John Kricher

The New Neotropical Companion
John Kricher
Chapter One

The New Neotropical Companion is the completely revised and expanded edition of a book that has helped thousands of people to understand the complex ecology and natural history of the most species-rich area on Earth, the American tropics. Featuring stunning color photos throughout, it is a sweeping and cutting-edge account of tropical ecology that includes not only tropical rain forests but also other ecosystems such as cloud forests, rivers, savannas, and mountains. This is the only guide to the American tropics that is all-inclusive, encompassing the entire region’s ecology and the amazing relationships among species rather than focusing just on species identification.

The New Neotropical Companion is a book unlike any other. Here, you will learn how to recognize distinctive ecological patterns of rain forests and other habitats and to interpret how these remarkable ecosystems function—everything is explained in clear and engaging prose free of jargon. You will also be introduced to the region’s astonishing plant and animal life.

Dominic Couzens: The extraordinary (and overlooked) water shrew

water shrewAsk most people whether they have heard of a water shrew and they’ll shake their head. If you tell them that there are 1.9 million water shrews in Britain and that they have a poisonous bite, then those same people are likely to raise their eyebrows, amazed they have never heard of it. The water shrew (not a water vole or a “water rat”) manages to keep a remarkably low profile for the extraordinary creature that it is.

Shrews are the mammals that look superficially like mice—they are small, brown and furry—yet are quite unrelated to them. They are flatter-bodied than mice and don’t hop, and have long snouts that move around in a somewhat robotic, mechanical fashion as they seek food. With small eyes (they are related to the almost-blind moles) and small ears, shrews lack the features that give mice and voles an easy identity to humankind. Shrews don’t live indoors or steal our food, either; they subsist on a diet of insects and other small living things. So shrews aren’t exactly on our doorsteps, asking to be noticed.

But shrews cross our paths alright, even if we aren’t looking. They are among the most abundant of all our mammals. Aside from the water shrew, there are 42 million common shrews and 8.6 million pygmy shrews in Britain; a veritable army of voracious insect- and worm-guzzlers living at our feet. They prefer to live in long grass, dense shrubbery, and other places where it’s easy to hide.

And, of course, they choose the waterside, too. The water shrew, the largest and best-turned out of our three common species, with its smart white underside contrasting with business-suit-black above, is the most aquatic of the three. Although it is perfectly at home in undergrowth away from water, its signature hunting method is to immerse in still or slow-flowing water, diving down to depths of 2m or more for up to 30 seconds, to snap up crustaceans, insect larvae, snails, worms, and small vertebrates such as newts, frogs, and fish. It is the only British mammal adapted to tap into this underwater niche of small freshwater life.

As it happens, the water shrew can also tackle prey larger than itself, by means of its remarkable venomous saliva, which immobilizes frogs or fish. The venom is a neurotoxin, causing paralysis and disorders of the blood and respiratory system. It is toxic enough to be a very unpleasant skin irritatant in humans that may take days to subside.

The water shrew has several adaptations to its preferred aquatic lifestyle. The surface of each foot is fringed with stiff hairs, increasing the area of the limb, like a flipper, allowing this mite to swim efficiently. The tail also has stiff hairs on the underside, making it act like a rudder, for steering. The hairs on the body also trap a layer of air, keeping the shrew warm underwater, even in the middle of winter.

Shrews, although small, don’t hibernate. Instead they must remain active throughout the winter, requiring a meal at least every two hours, day and night. It isn’t easy to sustain, and many shrews don’t survive. In fact, almost every adult dies after a single breeding season, meaning that only the juveniles born during the spring and summer survive to the next season—just another extraordinary aspect of this overlooked animal’s life.

Dominic Couzens is one of Britain’s best-known wildlife writers. His work appears in numerous magazines, including BBC Wildlife and BBC Countryfile, and his books include Secret Lives of Garden Wildlife and Britain’s Mammals: A Field Guide to the Mammals of Britain and Ireland.

Tuesday’s Trot – Icelandic Horse

Good news for all the horse lovers out there! Starting this week in our new “Tuesday’s Trot” feature, we’re highlighting some fun facts about various horses from Horses of the World. Kicking it off today is the Icelandic Horse.

From page 32 in Horses of the World:

Iceland has only one breed of horse, but what a breed it is! The Icelandic is one of the most amazing horses in the world, with its incredible variety of colors and its five gaits. Iceland has developed its own equestrian culture, and a specific saddle for it. The horse plays a major role in Icelandic mythology and its great sagas. Some Europeans use the term “pony” to describe this small horse, but the term “pony” isn’t used in Iceland, just as it isn’t in many countries of the world.

Icelandic equitation is based on the breed’s specific gaits (here, the tölt).

 

Icelandic Saddle

5 things you should know about the Icelandic Horse:

1. The Icelandic is particularly ancient and pure due to the ban, since 982, on importing new horses into Iceland. The horses that leave Iceland don’t return. The Icelandic has thus not undergone any crossing.

2. Adapted to an extreme climate, the Icelandic is very resilient and very hardy. Many horses spend the harsh winter outdoors. It is an easy keeper.

3. The Icelandic is a very intelligent horse; it is calm and friendly, but independent and energetic.

4. One of the unique characteristics of the Icelandic is its additional gaits, the tölt and the flying amble. It is one of the only gaited horses native to Europe, as European breeders have eliminated this characteristic in many breeds.

5. A horse with a strong identity, the Icelandic has been introduced successfully into many countries beginning in the twentieth century. There are currently more than 180,000 Icelandics throughout the world.

 

Horses of the World
Élise Rousseau
Illustrated by Yann Le Bris
Translated by Teresa Lavender Fagan
Sample Entry

Horses of the World is a comprehensive, large-format overview of 570 breeds of domestic and extant wild horses, including hybrids between the two and between domestic breeds and other equids, such as zebras. This beautifully illustrated and detailed guide covers the origins of modern horses, anatomy and physiology, variation in breeds, and modern equestrian practices. The treatment of breeds is organized by country within broader geographical regions—from Eurasia through Australasia and to the Americas. Each account provides measurements (weight and height), distribution, origins and history, character and attributes, uses, and current status. Every breed is accompanied by superb color drawings—600 in total—and color photographs can be found throughout the book.

Describing and depicting every horse breed in existence, Horses of the World will be treasured by all who are interested in these gorgeous animals.

 

A sneak peek at BIG PACIFIC, companion to upcoming PBS series

The companion five-part series on PBS: Big Pacific will air Wednesdays on PBS, June 21-July 19, 2017

The Pacific Ocean covers one-third of Earth’s surface—more than all of the planet’s landmasses combined. It contains half of the world’s water, hides its deepest places, and is home to some of the most dazzling creatures known to science. The companion book to the spectacular five-part series on PBS produced by Natural History New Zealand, Big Pacific by Rebecca Tansley breaks the boundaries between land and sea to present the Pacific Ocean and its inhabitants as you have never seen them before.

Illustrated in full color throughout, Big Pacific blends a wealth of stunning Ultra HD images with spellbinding storytelling to take you into a realm teeming with exotic life rarely witnessed up close—until now. Providing an unparalleled look at a diverse range of species, locations, and natural phenomena, Big Pacific is truly an epic excursion to one of the world’s last great frontiers. Take a sneak peek here:

 

 

More than superstition: Happy Groundhog Day!

The groundhog may have no talent for predicting the arrival of spring, but it surely can enlighten us on animals’ reactions to changing weather patterns. According to biologist Daniel T. Blumstein, celebrating Groundhog Day is about more than a superstition. In the Washington Post, he notes, “Understanding how individual groundhogs respond to environmental change is essential if we want to predict how animals will react to global warming and other human-driven habitat shifts.”

And no worries if Punxsutawney Phil sees his shadow on Groundhog Day, after all, if winter comes, can spring be far behind?

To know more about this mysterious mammal, check out Roland W. Kays and Don E. Wilson’s book Mammals of North America, an indispensable guide for amateur naturalists and professional zoologists alike.


Mammals of North America
Second Edition
Roland W. Kays & Don E. Wilson
Introduction
Mammals of North America APP

Covering 20 species recognized since 2002 and including 13 new color plates, this fully revised edition of Mammals of North America illustrates all 462 known mammal species in the United States and Canada—each in beautiful color and accurate detail. With a more up-to-date species list than any other guide, improved facing-page descriptions, easier-to-read distribution maps, updated common and scientific names, and track and scat illustrations, this slim, light, and easy-to-use volume is the must-have source for identifying North American mammals.