On the Web site for The Beauty of Ugly, you’ll get an in-depth look at some of these intriguing creatures. You’ll learn about the remarkable sensory abilities of the weird little star-nosed mole and the unusual social system of naked mole-rats and their imperious mole-rat queen, discover the threats faced by the Cape Griffon vulture, and get a fish-eye’s view of the needle-toothed viperfish and other deep-sea creatures, as photographed by a unique undersea camera called the Eye-in-the-Sea, designed by ocean researcher Dr. Edith Widder.

Online content for The Beauty of Ugly was originally posted online November 2007.

In the same way that inbreeding among human populations can increase the frequency of normally rare genes that cause diseases, the selective breeding that created the hundreds of modern dog breeds has put purebred dogs at risk for a large number of health problems, affecting both body and behavior.

Some conditions are directly related to the features breeders have sought to perpetuate among their dogs. As they deliberately manipulated the appearance of dogs to create or accentuate physical characteristics that were considered aesthetically pleasing, like the flat face of a bulldog or low-slung eyelids of a Bloodhound, breeders also created physical disabilities. The excessively wrinkled skin of the Chinese Shar-Pei causes frequent skin infection; Bulldogs and other flat-faced (or brachycephalic) breeds such as the Pekingese have breathing problems because of their set-back noses and shortened air passages; Bloodhounds suffer chronic eye irritation and infection.

The unnaturally large and small sizes of other breeds encourage different problems. For example, toy and miniature breeds often suffer from dislocating kneecaps and heart problems are more common among small dogs. Giant dogs such as Mastiffs, Saint Bernards, and Great Danes are nearly too big for their own good. Researchers have found a striking correlation between a dog’s large size and a frequency of orthopedic problems like hip dysplasia. Large dogs are often prone to heat prostration because they can’t cool down their bodies (tiny dogs, by contrast, have a hard time staying warm), and because of the massive weight they must support, these breeds are prone to malignant bone tumors in their legs. Meanwhile, the huge head and narrow hips of the Bulldog can necessitate that their pups must be born by Caesarean section.

Other health problems among purebreds are the product of both inbreeding and bad genetic luck. The genes responsible for many genetic diseases are “recessive,” which means that two copies of a damaged gene, one from the mother and one from the father, must be present in an individual for the disease to occur. Individuals that carry only one copy of the disease gene don’t have the condition, and are carriers of the disease. Normally, because disease genes are relatively rare, it is unlikely that both the mother and the father will be carriers, and even less likely that they’ll both give the disease gene to their offspring. But that’s not the case for purebred dog breeds, where genetically similar individuals are intentionally mated, increasing the concentration of disease genes. It’s like stacking a deck of cards with ten extra aces and ten extra face cards; the loaded deck increases your chance of hitting blackjack in a game of 21-but what you “win” might be allergies or a predisposition to cancer.

Bloodhounds suffer chronic eye irritation and infection.

Skin problems

A skin allergy, atopic dermatitis, inflicts itchy, inflamed skin on as many as 15 percent of all dogs, but certain breeds are particularly susceptible. Dog breeds prone to atopic dermatitis include Dalmatians, Vizslas, and several terriers, such as the Boston Terrier, Bull Terrier, and the West Highland White Terrier. The numerous skin folds of a Chinese Shar-Pei, so valued by some breeders, can become breeding grounds for staphylococcus and other bacteria, which cause frequent skin infections. Also, excess wrinkles of skin on the face can rub on the eye, causing lesions and, potentially, blindness.

Immune system disease

In autoimmune disorders, an individual’s immune system, which normally works to fight off foreign invaders, launches a misguided attack against its own tissues and cells. A number of inherited diseases compromising the immune system have been noted in dogs, including primary severe combined immunodeficiency (a dog version of the “bubble boy” disease) among Basset hounds, Cardigan Welsh Corgis, and Dachshunds. Addison’s disease, an autoimmune disease that affects the hormone-producing adrenal glands, occurs more frequently among several particular breeds, including the Bearded Collie, Portuguese Water Dog, and Standard Poodles. Diabetes mellitus, an autoimmune disorder affecting the body’s response to sugars, shows up more frequently among Samoyeds and Australian Terrier dogs.

Blood disorders

Bassett Hounds are prone to an inherited abnormality the effects the ability of the platelets in the blood to clump together after an injury. The blood doesn’t clot properly, leading to hemorrhage and bruising. Clotting problems also plague dogs with von Willebrand’s disease, a genetic condition frequent in Doberman Pinschers.

Neurological, behavioral, and sensory

Neurological and behavioral problems afflict many pure breeds. Bull Terriers, for example, often compulsively chase their tails. Pugs are be predisposed to Pug Dog encephalitis, a fatal brain disease. Scottish Terriers are affected by Scottie Cramp, a disorder that causes the dogs to lose muscle control when they get excited. German Shepherds may inherit degenerative myelopathy, a crippling spinal cord disease that causes weakness and eventually paralysis.

Hearing and vision

Hereditary hearing loss is common in Dalmatians, Australian Cattle Dogs, and English Setters. Alaskan Malamutes, Siberian Huskies, Samoyeds, Bichon Frise, and more than 60 other purebred dogs suffer from inherited forms of cataracts, while progressive retinal atrophy, a common cause of blindness in purebreds, is particularly a problem in Old English Sheepdogs and Papillons.

Heart disease

Sudden death from cardiac disease is recurrent in several dog breeds, including Doberman Pinschers, Great Danes, Irish Wolfhounds, and German Shepherds. Boxers can be genetically predisposed to an irregular heartbeat. High blood pressure afflicts many small breeds including Poodles, Cocker Spaniels, Staffordshire terriers, among others.

Other organs and systems

Low thyroid function crops up most frequently in Alaskan Malamutes, English Setters, Golden Retrievers, Keeshonds, Samoyeds, and Siberian Huskies. Gastric torsion, or bloat, a potentially life-threatening inability to expel gas from the digestive system, is common among deep-chested breeds such as the Great Dane, Doberman, and German Shepherd. An inherited form of kidney disease affects English Cocker Spaniels, while Dalmatians are prone to kidney stones and Basenjis suffer from Fanconi Syndrome, a potentially fatal inherited disease in which the kidneys fail to reabsorb nutrients. Liver damage and cirrhosis are common in Bedlington Terriers because of an inherited condition called copper toxicosis, in which high levels of copper accumulate in the liver.

Cancer

Cancers are strongly influenced by genetics, and so it is not surprising to find various types of cancer among different dog breeds. For example, bone cancer, or osteosarcoma, is considerably more frequent among large and giant breeds of dogs, such as the Irish Wolfhound, Great Dane, Rottweiler, Labrador and Golden Retriever, Greyhound, and Saint Bernard, because their bones are stressed by carrying so much weight. High rates of malignant blood vessel tumors are seen among Golden Retrievers, which are also prone to leukemia and brain tumors. German Shepherd Dogs and Chow Chows are predisposed to gastric cancer, while Scottish Terriers are 18 times more likely to develop bladder cancer than are other breeds.

Orthopedic

Hip dysplasia, in which looseness in the hip joint causes excessive wear that eventually leads to arthritis, is most common among large dogs, especially those like the German Shepherd Dog and the Saint Bernard which have heavy, broad hips. The long neck and large head of breeds such as the Great Dane and the Doberman can cause the compression of the spinal cord in neck vertebrae, leading to wobbling and falling (”wobbler syndrome”). Selective breeding of the disproportionately short legs of breeds such as the Basset Hound and the Dachshund has led to bowed legs and chronic problems with elbow dislocation; the short legs and long back of Dachshunds causes them to suffer more often from ruptured vertebral disks. Because of their small bones, toy and miniature breeds are more likely to experience patellar luxation, the slipping or dislocation of the kneecaps.

NATURE’s two-part special Dogs That Changed the World tells the epic story of the wolf’s evolution, how “man’s best friend” changed human society and how we in turn have radically transformed dogs.

From the tiniest Chihuahua to the powerful and massive English Mastiff, modern domesticated dogs come in a bewildering array of shapes and sizes, with an equally diverse range of temperaments and behaviors. And yet, according to genetics, all dogs evolved from the savage and wild wolf — in a transformation that occurred just 15,000 years ago.

In Part One, “The Rise of the Dog,” you’ll learn about how the domestication of dogs might have taken place, including the theory of biologist Raymond Coppinger that it was the animals themselves — and human trash — that inspired the transformation. The genetic analysis of Peter Savolainen of the Royal Institute of Technology in Sweden has placed the origins of domesticated dogs — and those of the first dog — in East Asia. You’ll also discover 14 dog breeds that controversial genetic studies show are the most ancient — and the best living representatives of the ancestors to all living dogs.

Preview Part Two: Dogs by Design

Over 400 breeds of dog are recognized around the world, each unique for its personality, habits, and form. Most of these breeds exploded onto the scene over the past 150 years, spurred by the Victorian-era passion for the “dog fancy” — the selective breeding of dogs to enhance particular characteristics. By tinkering with its genetics, humans made the dog the most varied animal species on the planet — and also created a host of hereditary health problems.

Despite the plethora of new shapes and sizes, dogs have retained the instincts bred into their ancestors by thousands of years of work: the urge to herd or hunt, to dig and to guard. In Part Two, “Dogs by Design,” you’ll discover how these hard-wired behaviors help different types of dogs, from hounds to herders, excel at different tasks (and why it can sometimes be so difficult to train them to do otherwise). You’ll also learn how dogs’ finely tuned senses are serving humans and saving lives.

To order a copy of Dogs That Changed the World, please visit the NATURE Shop.

Online content for Dogs That Changed the World was originally posted April 2007.

GRADE LEVEL: 9-12

TIME ALLOTMENT: Three 45-minute class periods

OVERVIEW: The traditional view of animal behavior is that it is driven by inherited, innate instincts, but recent scientific research is revealing a larger role for complex cognitive processes among many species. The lesson will explore some of the more commonly accepted indicators of animal intelligence as demonstrated by the most brainy of all birds-the raven.

Students will first explore a series of science Web sites to compile a list of certain animal behaviors and abilities that indicate higher intelligence. They will then find and analyze examples of these behaviors and abilities as demonstrated by ravens in selected clips from the NATURE episode “Ravens.” Based on what they learn, students will then work in groups to create a theoretical intelligence-challenging “obstacle course” for ravens.

This lesson could be used following (or in conjunction with) the lesson “Symbiotic Strategies.”

SUBJECT MATTER: Living Environment/Biology

LEARNING OBJECTIVES:

Students will be able to:

• Compare “classical” and “modern” views of bird brain anatomy and function, and compare bird brains to human brains;
• Describe various raven behaviors and abilities that indicate intelligence;
• Explain why many of these behaviors indicate cognitive intelligence rather than simple inherited instinct;
• Assemble a realistic sequence of intelligence-testing challenges for ravens.

STANDARDS AND CURRICULUM ALIGNMENT:

National Science Education Standards

CONTENT STANDARD C: As a result of their activities in grades 9-12, all students should develop understanding of:

THE INTERDEPENDENCE OF ORGANISMS

• Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.
• Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.

THE BEHAVIOR OF ORGANISMS

• Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.
• Like other aspects of an organism’s biology, behaviors have evolved through natural selection. Behaviors often have an adaptive logic when viewed in terms of evolutionary principles.
• Behavioral biology has implications for humans, as it provides links to psychology, sociology, and anthropology.

CONTENT STANDARD G: As a result of activities in grades 9-12, all students should develop understanding of

NATURE OF SCIENTIFIC KNOWLEDGE

• Scientific explanations must meet certain criteria. First and foremost, they must be consistent with experimental and observational evidence about nature, and must make accurate predictions, when appropriate, about systems being studied. They should also be logical, respect the rules of evidence, be open to criticism, report methods and procedures, and make knowledge public. Explanations on how the natural world changes based on myths, personal beliefs, religious values, mystical inspiration, superstition, or authority may be personally useful and socially relevant, but they are not scientific.
• Because all scientific ideas depend on experimental and observational confirmation, all scientific knowledge is, in principle, subject to change as new evidence becomes available. The core ideas of science such as the conservation of energy or the laws of motion have been subjected to a wide variety of confirmations and are therefore unlikely to change in the areas in which they have been tested. In areas where data or understanding are incomplete, such as the details of human evolution or questions surrounding global warming, new data may well lead to changes in current ideas or resolve current conflicts. In situations where information is still fragmentary, it is normal for scientific ideas to be incomplete, but this is also where the opportunity for making advances may be greatest.

NEW YORK STATE CORE CURRICULUM ALIGNMENTS

Living Environment Core Curriculum

Standard 1: Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions.

Key Idea 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing and creative process.

Performance Indicator 1.1: Hone ideas through reasoning, library research, and discussion with others, including experts.

1.2a Inquiry involves asking questions and locating, interpreting, and processing information from a variety of sources.

Standard 4: Students will understand and apply scientific concepts, principles, and theories pertaining to the physical setting and living environment and recognize the historical development of ideas in science.

Key Idea 1: Living things are both similar to and different from each other and from nonliving things.

Performance Indicator 1.1 Explain how diversity of populations within ecosystems relates to the stability of ecosystems.

1.1a Populations can be categorized by the function they serve. Food webs identify the relationships among producers, consumers, and decomposers carrying out either autotropic or heterotropic nutrition.

1.1b An ecosystem is shaped by the nonliving environment as well as its interacting species. The world contains a wide diversity of physical conditions, which creates a variety of environments.

1.1c In all environments, organisms compete for vital resources. The linked and changing interactions of populations and the environment compose the total ecosystem.

Key Idea 6: Plants and animals depend on each other and their physical environment.

Performance Indicator 6.1 Explain factors that limit growth of individuals and populations.

6.1g Relationships between organisms may be negative, neutral, or positive. Some organisms may interact with one another in several ways. They may be in a producer/consumer, predator/prey, or parasite/host relationship; or one organism may cause disease in, scavenge, or decompose another.

MEDIA COMPONENTS:

Video

NATURE: Ravens, selected segments:

Clip 1: “Raven Adaptability”

Ravens are the most intelligent birds in the crow family.

Clip 2: “Feeding Time”

Ravens’ smarts can be observed in many situations.

Clip 3: “The Roost”

Why do ravens gather together?

Clip 4: “Testing Intelligence”

Scientific experiments test how ravens think.

Access the streaming and downloadable video segments for this lesson at the Video Segments Page.

Web Sites

Bird Brain
A site from PBS’s NOVA exploring the most current understanding of bird brain physiology, revealing a less instinctive and more cognitive brain structure than has traditionally been thought.

Measuring Intelligence
A site from the Smithsonian National Zoological Park addressing some of the basic difficulties in determining bird intelligence.

The Animal Mind
A NATURE site from PBS describing the intelligent behavior of four different species.

Symbiosis
A site from North Carolina State University featuring descriptions of the different types of symbiotic relationships among animals.

Nutcrackers
A PBS site exploring intelligent behavior in various bird species.

MATERIALS

For each student:

• “Raven Reason” Student Organizer. (PDF) (RTF)
• Computer with Internet access

For the class:

• “Raven Reason” Student Organizer Answer Key (PDF) (RTF)
• Computer with Internet access and projection system for showing video clips
• Blackboard or whiteboard

PREP FOR TEACHERS:

Prior to teaching this lesson, you will need to:

Preview all of the video clips and Web sites used in the lesson.

Download the video clips used in the lesson to your classroom computer, or prepare to watch them using your classroom’s Internet connection.

Bookmark the Web sites used in the lesson on each computer in your classroom. Using a social bookmarking tools such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Gather the necessary materials listed above in advance of teaching the lesson. Download and print the “Raven Reason” student organizer and make copies for each student in your classroom.

Note that the computer requirements in the “Materials” section reflect an ideal arrangement. You may find it necessary to divide the class into a number of groups equal to the computers available, adjusting the lesson instructions accordingly.

Next: Proceed to Activities

Red Fox (Vulpes vulpes)

• Type: Mammal
• Family: Canidae
• Habitat: Highly variable. Edge forests, deserts, tundra, cities, and suburban areas
• Location: Most of the Northern Hemisphere and Australia
• Diet: Rodents, birds, insects, carrion and fruit
• Average lifespan in the wild: 3 years in the wild; 10-12 years in captivity
• Size: Head and body 18-35.4 in (45.5-90 cm); tail 11.8-21.8 in (30-55.5 cm)
• Weight: 6.6-30.8 lbs (3-14 kg)

The small, slender bodies of red foxes are designed for speed and agility. In proportion to other canid species, red foxes have longer legs and smaller stomachs — adaptations that allow the animal to run nearly 30 miles per hour. A smaller stomach means they need to eat more often, and red foxes opportunistically eat a wide variety of foods as they traverses their home range at night, such as insects, fruits, earthworms, and scraps left by humans. Although they also hunt during the day, red foxes have very acute senses to help them succeed as nocturnal predators. Their eyes are designed to work well in low light conditions, and they maneuver their erect triangular ears to locate the faint rustling noises of rodents. When a mouse is detected, red foxes stand alert and motionless, using their ears and eyes to pinpoint the location of the rodent. Then they launch themselves into the air at a 45-degree angle, and land on the mouse, pinning it to the ground.

Red foxes are territorial, and mark their home range using feces and urine. A dominance hierarchy determines who breeds, and the dominant female gives birth each year to a litter of 3 to 12 pups. Mothers keep their offspring in dens, and non-breeding adults help care for the young. There are several different red fox color variants, which can often be seen within a litter. These include the silver, black, and cross variants. All red foxes have thick fur, a wide, bushy tail, and a narrow, pointed muzzle.

Red foxes have the largest distribution of any canid species. They can be found in almost the entire northern hemisphere, in part because they have such a diverse diet. As a species, red foxes have adapted well to human expansion. They thrive in urban areas, and have benefited from the human conversion of forest into agricultural lands. Red foxes are often seen as a threat to poultry and young livestock, even though they usually prey only on weak and sick animals. Though many farmers consider them pests, red foxes play a major role in controlling populations of crop-threatening animals like rabbits and rodents.

Did you know: Red fox predators are eagles, coyotes, gray wolves, bears, mountain lions, and humans, who have been hunting red foxes since the 4th century BC.

Photo by Otmar Penker © ORF / Die ARGEntur Filmproduktions GmbH