A wisp of steam curls lazily above the volcano’s peak. The ground murmurs and groans. The mountain’s slopes bulge ominously. Is the volcano ready to blow? Or is it just restless, and years — or perhaps centuries — away from a potentially dangerous eruption?

Scientists working in Hawaii and elsewhere are using more sophisticated tools than ever to try to predict the behavior of volcanoes. NATURE’s Violent Hawaii offers a glimpse of some of these tools, such as special scoops to collect lava samples. But volcanologists have a lot more gear stored in their toolboxes. Here’s a sampling:

Tiltmeters

Scientists use tiltmeters to measure extremely subtle changes in a volcano’s slope. An increasingly steep side, for instance, can indicate a buildup of gas and molten rock inside the mountain, making it swell. Modern tiltmeters can detect a change of just one part per million; that’s equivalent to being able to detect someone lifting the end of a half-mile-long board just one millimeter — or about the height of a dime.

Gas Samples

A geologist cools a sample of molten lava in a can of water.

The gas emanating from a volcano’s vents and crater can tell scientists a great deal about what is happening deep beneath the earth. Changes in concentrations of carbon and sulfur gases might signal the arrival of a new batch of magma, or molten rock. The amount of malodorous hydrogen sulfide gas may also indicate an impending eruption.

Obtaining gas samples can be dangerous. A spectrometer — an instrument that analyzes light coming through a volcanic plume — allows scientists to conduct a study from a safe distance. Since each type of gas emits its own distinctive light signature, researchers are able to identify what is coming out of the volcano. In 1991, such gas analysis tools helped researchers predict the eruption of Mount Pinatubo in the Philippines, saving countless lives.

Thermal Imagers

Special cameras carried by aircraft or satellites can take pictures of the heat emitted by volcanoes. These “thermal images” help researchers identify new lava flows (which are hotter) and older, cooler ones.

Seismic Monitors

Monitoring a mountain’s seismic activity was one of the first methods used to predict volcanic eruptions. An increase in earthquakes can be a sign of an impending eruption. Researchers use seismic monitors to track the many small tremors that occur around a volcano. Modern seismometers can record the intensity, escalation, and epicenters of earthquakes. In Hawaii, researchers have more than 60 seismic monitoring stations on the Big Island alone.

Radar Mapping Instruments

Radar mappers carried by aircraft and satellites produce remarkably detailed three-dimensional maps of the Earth’s surface. They help researchers predict where lava flows might travel — or predict the path of the incredibly dangerous steaming mudslides produced by some volcanoes. Local officials can then use this information to evacuate threatened areas in the event of an eruption.

(Click here for a printer-friendly version of this lesson.)

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

Background:
The traditional view of birds was that they simply acted by a set of inherited instincts, but new scientific research is revealing a larger role for complex cognitive processes in their behavior, including communication, counting, memory, and basic problem solving. These excerpts from the NATURE episode “Ravens” demonstrate several of these commonly accepted indicators of animal intelligence as demonstrated by the most brainy of all birds-the raven.

Suggested Focus Questions:

Clip 1: Raven Adaptability

1. What makes ravens so adaptable?
2. Ravens eat meat but they don’t kill it themselves. What kind of animal does this make them?
3. How might ravens’ relationship with coyotes indicate their intelligence?

Clip 2: Feeding Time

1. What skill does the raven demonstrate at the dumpster?
2. When and why might a raven puff out its feathers?
3. How might ravens’ caching behavior indicate intelligence?

Clip 3: The Roost

1. What’s one theory about why young ravens roost together?
2. How might one raven be able to tell if another knows where food is?
3. Why would a young raven, having found food, call over other ravens to help eat it?

Clip 4: Testing Intelligence

1. Why is it so difficult to measure intelligence in animals?
2. Why is it important that the ravens have never been exposed to the experiment before?

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right=click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Clip 1: “Raven Adaptability“

Clip 2: “Feeding Time“

Clip 3: “The Roost“

Clip 4: “Testing Intelligence“

Big Sur’s rugged mountains, crashing surf, and abundant wildlife have captivated generations of visitors. But the region has also attracted scientists bent on understanding this remarkable biological melting pot, where plants and animals from dramatically different ecosystems often mingle side by side. One biologist who has taken a close look is Paul Henson, who lived in the region in the 1980s and, with Don Usner, wrote The Natural History of Big Sur (University of California Press, 1996).

Big Sur attracts scientists due to its status as a biological melting pot. In no other part of the world do fog-loving coastal redwoods thrive on one slope of a canyon while arid-climate yuccas grow on the other, the book notes. Similarly, sea otters and cormorants live near dry-climate creatures like canyon wrens and whiptail lizards.

Henson, who now works for the U.S. Fish and Wildlife Service overseeing biological studies in Hawaii and other Pacific Islands, spoke with NATURE about Big Sur’s remarkable diversity.

How did you come to write this book?

I earned my undergraduate degree at the University of California, Santa Cruz, and did a lot of work at a university reserve called Big Creek that covers a big chunk of the Big Sur coast. Then, in the mid-1980s, I got a job doing sea otter research. During my down time, we started on the natural history guide. We realized that there was lots of good information floating around, but it hadn’t been consolidated in one place, and made accessible to scientists and understandable to regular readers. So we decided to do it.

Big Sur attracts scientists due to its status as a biological melting pot.

What makes Big Sur unusual?

For lack of a better term, it represents a kind of harmonic convergence of different ecological zones. It’s where the north meets the south, for instance. What’s called the Oregonia province to the north meets the Californian province to the south. So you have redwood trees meeting cacti and intermingling. You have northern and southern species of marine alga. One minute, you are hiking along in a wet cool canyon, and all of a sudden there will be a cactus. One minute it smells like Oregon and the next it smells like Mexico.

The geology plays are role, right?

The geology and topography forms the basis for it all, and it has driven geologists crazy for years. It’s incredibly jumbled and complicated. You have all these faults and slices of rock that have moved over time. And then on top of that you have a very interesting climate. Big Sur has a Mediterranean climate, which it shares with just four or five other areas in the world. It’s a climate that is extremely conducive to a lot of plants doing well. Taken together, those things make it one of the most ecologically fascinating and diverse areas in North America.

Big Sur is one of the most ecologically diverse areas in North America. Big Sur has its share of rare species …

Yes. In the 1800s, it attracted a lot of famous botanists because there are plants there that grow nowhere else. The Santa Lucia mountains have a lot of unique species because, at times, that area has been an island. So plants and animals that lived there have been cut off from other populations and evolved in their own direction. Probably the most famous species is the Santa Lucia fir tree, which is found in just a few canyons and nowhere else in the world. It looks like a tree in a Dr. Seuss book — the top droops over and it has these interesting cones.

Do you have a favorite spot in Big Sur?

Probably the Little Sur River Valley in the Ventana Wilderness. It has such a great combination of giant redwood trees and really dry chaparral. It’s one of those places where you have very different ecosystems within spitting distance of each other.

How about a favorite animal?

Probably golden eagles. The raptor [bird of prey] populations there are amazing. There are places where you can sit on a hillside, look out, and see five or six different raptors in a minute — golden eagles, red shouldered hawks, kites, red tailed hawks, kestrels. It’s a great show.

Meet the scientists featured in Deep Jungle: The Beast Within.

Chloe Cipolletta

Chloe Cipolletta Since January 1998, Chloe has been attempting to habituate western lowland gorillas in Dzanga-Ndoki National Park in the Central African Republic. Previously she worked with Christophe Boesch to habituate chimpanzees in the Tai Forest off the Ivory Coast from 1994 to 1996, and for a brief period at the orangutan research station at Gunung Leuser National Park in Sumatra.

Although mountain gorilla habituation had been made famous by the work of Dian Fossey, getting western lowlands to accept human presence was thought to be impossible when Chloe first began research. This was due to the extremely dense forest vegetation and the historically poor relationship between gorillas and man in Central Africa (the only humans the gorillas knew were hunters).

From August 1998 on, Chloe and her team focused their study on one gorilla group, the Munye. Alongside BaAka pygmies, who have incredible tracking skills, Chloe was able to locate and then integrate herself with the gorillas nearly every day. The gorillas initially reacted to Chloe’s team with aggression and fear, but as time passed these expressions were replaced, first with indifference to the intruders, and eventually with curiosity about them. By the time NATURE filmed at Dzanga in November 2003, the gorillas seemed almost completely comfortable with Chloe and her team sitting just a few yards away.

Although Chloe’s work, sponsored by the World Wildlife Fund and the German Technical Cooperation, has primarily focused on encouraging tourists to visit Dzanga-Ndoki (thereby providing an alternative to logging as a means of financial stability), it has also allowed new insight into the lives of western lowland gorillas.

David Watts

David Watts David P. Watts (Ph.D., Chicago 1983) is a professor of anthropology at Yale University whose research specialty is the behavior and ecology of nonhuman primates. In Panama, he has done fieldwork on the behavior of white-faced capuchin monkeys; in Rwanda, on the behavioral ecology of mountain gorillas; and in Uganda, on the behavioral ecology of chimpanzees. He was also the Director of the Karisoke Research Centre in Rwanda for two years.

In collaboration with Dr. Jeremiah Lwanga and Dr. John Mitani, David has maintained a research project on chimpanzee behavior at Ngogo, in the Kibale National Park in Uganda, since 1995. With more than 70 adult males and females and approximately 150 individuals in total, this community is the largest that has been reported thus far in the wild. Due to the extremely large number of males in this group, the Ngogo chimpanzees hunt often and with an unusual degree of success. The male chimps also frequently patrol the boundary of their territory. This has led to several documented cases of lethal intergroup aggression. David’s work has contributed to our understanding of why chimpanzees hunt and share meat, and has provided insight into the intriguing evolution of sharing.

Charles Golden and René Muñoz

Charles Golden and René Muñoz Charles Golden is an archaeologist with the University of Brandeis. His particular interest is the pre-Hispanic cultures of Mesoamerica, especially the Mayan civilization. His main field site now is in Guatemala; he has also worked in Belize and Honduras. His doctoral research was carried out in the Royal Palace of the Maya site of Piedras Negras in the Sierra Del Lacandon National Park of Guatemala. He is currently the director of the Sierra Del Lacandon Regional Archaeology Project, the first systematic archaeological survey in this region, which is focused on developing a better understanding of political, cultural, and social boundaries and frontiers between classic Maya polities or city-states. Charles has taught at the University of Pennsylvania, the University of Delaware, and Haverford College.

René Muñoz is a doctoral candidate in the Department of Anthropology at the University of Arizona. He has conducted research in Arizona, Texas, Belize, and Guatemala. Most recently, he has been working as the ceramicist for the Piedras Negras Archaeological Project.

In Deep Jungle, Charles and Rene travel to Guatemala, to a newly discovered Mayan temple called Tecolote. In 2004 they discovered nearly a dozen new sites. Following that field season, they received word that an inscribed monument had been looted from a site previously unknown to them. Luckily, the monument was recovered by the authorities, and these explorers now know there is at least one more big site out there ready for excavation!

Charles Higham

Charles Higham Professor Higham is the James Cook Fellow in the Department of Anthropology at the University of Otago in New Zealand. Since 1969 he has conducted fieldwork in Thailand and Cambodia. His areas of study cover the origins of rice agriculture, the development of the Bronze Age, and the origins of the civilization of Angkor. He has written many books on these subjects, and his work has been recognized internationally with his election as a Corresponding Fellow of the British Academy. On location for Deep Jungle in Angkor Wat, Charles reveals the story of the rise and fall of the civilization that once lived there.

Meet the scientists featured in Deep Jungle: Monsters of the Forest.

Martin Nicholas

Martin Nicholas Arachnologist Martin Nicholas shares his home with hundreds of spiders, but having arachnids for housemates doesn’t stop him from circling the world seeking more. Of the more than 35,000 spiders known to exist on Earth, Nicholas finds tarantulas to be the most enigmatic and fascinating.

In Deep Jungle, Martin travels to Peru in search of a contender for Biggest Spider in the World, a title currently held by the 11-inch Venezuelan Goliath Birdeater. Martin’s quarry is an uncatalogued species known as the chicken-eating spider because of eyewitness claims that it’s able to drag chickens into its burrow on the edge of jungle clearings. Estimates put this spider at around 10 inches across, from one hairy foot to another.

David Roubik

David Roubik David Roubik always wanted to be a tropical biologist. He began studying insects at the age of four and learning Spanish at the age of 10, with the idea that the language might come in handy working in the tropics when he grew up. Today, he is a research entomologist for the Smithsonian Tropical Research Institute with a particular interest in bees.

Along with David, Deep Jungle explores the role of euglossine bees in the complex ecosystem surrounding the Brazil nut tree. David discovered that they use the scent of several different orchids to produce a cocktail of smells that then establishes their social position in the mating game. These scents allow the bees to declare hierarchical power over other males and let the females know who’s the leader of the swarm, so to speak. Euglossines require an environment containing a particular type of orchid in order to breed successfully. Without this, the bees fail to breed, and therefore plants that depend on them like the Brazil nut tree, fail to propagate.