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Destination: Galapagos Islands Cyber Field Trip

Photo of Sherri Steward
Q&A with Sherri Steward

You can learn more about Sherri Steward in Meet the Team.


Question When will this show you are filming about the Galapagos air on PBS? I'm so anxious to see it. (Mike, 6th grade, Carl Sandburg Middle School Levittown, PA)
Answer The Scientific American Frontiers television special, hosted by Alan Alda, will air in October of 1999 on PBS. The website is a permanent part of the larger Scientific American Frontiers website.
Question Although the motto for wildlife management is "let nature take its course," are there any populations that researchers are watching for signs of inbreeding? And would anything be done to aid a faltering population? (Amy Christopherson, College Teacher)
Answer Inbreeding is always a concern in wildlife management. I asked Dr. Lynn Fowler, an expert on the giant Galapagos tortoise, about inbreeding of a particular population on Santa Cruz Island, where the Charles Darwin Research Station is located. In a captive breeding program there, about 800 individuals descended from only 14 tortoises, only two of which were males. One of the males had been translocated from the San Diego Zoo in order to increase the genetic diversity. Lynn and the other scientists involved currently do not believe that inbreeding is a problem with these animals and there are currently no plans for intervention.
Question How can you tell how old the Galapagos tortoises are if you don't have any records? (Michelle Dewar, Middle School Student)
Answer Very good records have been kept on the Galapagos tortoise for generations. These tortoises actually have concentric growth rings on their carapaces, which can be counted much like the growth rings of a tree.
Question How many babies does a seal have every year? (Nicole Citara, Middle School Student)
Answer Fur seals usually have one pup every two years. The mothers are very careful caretakers of the young. The babies have just about the cutest faces I have ever seen!
Question I am enjoying your trip vicariously. My son and Alex were watching your videos and were wondering if you have observed any examples of altruistic behavior so far. I personally am fascinated by this self sacrificing behavior and its ramifications on the genetic pool. (Scott E. Kasden, MD)
Answer Let me first say that I wish Alex and Matt (the iguana aficionados) were here to see these magnificent creatures! Although altruistic behavior has indeed been recorded in large-brained animals, such as chimps, no such behavior has been documented here. In contrast to this type behavior, the most interesting behavior I have seen is siblicide in masked boobies. Masked boobies have two chicks, and the older offspring almost always kills the younger -- with parental collusion! Since the boobies are your favorite, I know you would love this place!
Question Which species of animals on the Galapagos Islands has most evolved or changed ever since they were first there? (Eugene B., Middle School Student)
Answer In terms of physiological and structural change, The marine iguanas have evolved extensively from their land ancestors.
Question We are measuring the pH and the DO levels of pondwater near our school and we were wondering what kind of water you were using in your tests? (Ocean water? pond? lake? stream? well water?) We want to be sure that the type of water is controlled, if possible. (Mrs. Law's class)
Answer We are measuring DO, pH, etc. of sea water, brackish waters, and lagoons, all of which have had fairly high salinity concentrations. Some of these values will probably differ from your school yard, but the fun thing about science is to answer the question, "Why?"
Question Why are so many species in the Galapagos unique only to the islands and found nowhere else in the world? (Eugene, High School Student)
Answer The Galapagos is home to many species nowhere else on Earth. One reason for this is that organisms evolved to fill open ecological niches that existed when they first arrived. For example, although the 13 species of Darwin's Finches are thought to have derived from one common ancestor, each evolved with unique physiological, structural and behavioral adaptations. This enables each, which have evolved into distinct species, to successfully adapt to their ecological roles and exploit these new niches.
Question What type(s) of pollution affect the Galapagos Islands and how does the pollution threaten the wildlife? (Keithe Loomis, Middle School Student)
Answer Unfortunately, pollution is a problem even in the most remote environments. Here in the Galapagos one of the biggest problems is a burgeoning human population and the waste (inorganic and organic) that is created as a result. Traditionally, inorganic waste has been burned, but tougher laws have are requiring all waste to be transported to the mainland, and recycling programs have been introduced. All-in-all, the Ecuadorian government is doing a good job of protecting this delicate and wonderful natural resource.
Question What type of habitat do pelicans live in? And how old do they live to be? (Ray Brown, Middle School Student)
Answer Pelicans are seabirds and live in coastal areas, close to water. They can live up to 25 years.
Question How fast can the beak of a finch change (or evolve) due to a change in its environment or food source? I have heard that some of the finches have shown changes in just a few generations. (Mark Klausing, Middle School Teacher)
Answer Recent studies have shown selective changes in beak size have occurred in as short a time span as one year. A study of Galapagos Ground finches, by Grant, has shown that during a recent drought, large beak size proved to be a selective advantage. Because males have larger beaks than females, as many as six times more females perished than males. Beak size is clearly genetic, and although there are fluctuations in short term changes determined by environmental conditions, it appears that evolution is occurring very quickly.
Question Could you address the major criticism of Darwin's Theory, i.e., the absence of intermediate species, or their fossils, on the Galapagos Islands. Is anyone doing excavations there looking for fossils? (Wolfgang Demmel)
Answer Evolution often occurs so rapidly in the Galapagos, that "intermediate species" can actually be seen and studied, making much fossil evidence unnecessary. For example, in the Grant study of Darwin's finches, break size was selected for and evolutionary changes resulted in only one year. This type of selection, with actual physiological, structural changes have occurred in many species here. This is one reason that the Galapagos Islands are so important to biologists; it offers a glimpse into how evolution actually works.
Question Why is it that you said you guys missed the penguins? Is it because they are only visible at certain times of the day, or seasons? (Ashley, Jenn, Vijay, John, Ed , Caroline, 7th Grade, N.J.)
Answer We missed the penguins only because we were unable to take the panga ride to their location. There were five penguins spotted, and they are definitely a presence in the islands, but unfortunately we were not able to see them.
Question It says that the Humboldt Current brings cold temperatures in this time of year but all you guys are wearing shorts and tanktops. Why? (Bio5, Group3)
Answer Although the water temperature is fairly cold here, the air temperature can be pretty hot. Today, on Tower Island, we were all very hot and sunburned. I have found that the water is simply too cold for me to snorkel without a wetsuit. I really froze last time I snorkeled, but it was worth it since I saw some great marine life, including a beautiful sea turtle!
Question Hello Ms. Steward, Your biology class wants to know if the weather in the Galapagos Islands is still affected by El Nino? (Andreae Pohlman, High School Student)
Answer To my biology students: there are always "ninos" occurring in the Galapagos. This weather patterns lead to many changes in wildlife populations, but it is unclear as to whether these effects will remain in the long run. Hey, you guys are great! Keep up the good work...I miss all your smiling faces!
Question Are there any specific migration patterns in animal groups caused by weather? (Luke Wardensky, High School Student)
Answer There are many migratory patterns here, especially with some of the birds. Weather is a big factor affecting all the animals (and plants) on these islands. Abiotic factors, such as weather are just as important as biotic factors (predators, etc).
Question What type of volcanoes exist on the Isabela Island? Which volcanoes on Earth are comparable? Are they active, dormant, or extinct? Are they cylinder or cone? What type of lava is on Isabela Island and where? (Michale F., Middle School Student)
Answer Isabela Island consists of six shield volcanoes. The islands are still quite active and eruptions occur frequently. A few years ago, Dr. Lynn Fowler, our naturalist, was completely isolated while studying the giant tortoises on one island. A massive explosion occurred on a nearby island and she was totally covered in ash. She actually took pictures of the lava flows that were spectacular. She admitted to us that the sight looked like "the end of the world." What a brave lady!
Question I just wanted to say good job. You are impressive as always! You are a great educator and friend! Will the experience you have carry over to your classroom? If so, in what way? Will it carry over to your renowned Ecology Center? How? Great job... and I love your Journals! (Justin Adams, College Student)
Answer Hi Justin! Of course, it will. You know that I will be showing these slides and talking about this journey in all my classes. If I'm lucky, I will turn out more students like you!
Question Hi Sherri! Glad to see you made the trip safely. With ecotourism on the rise, how safe are these pristine sanctuaries? What controls are in place to protect these islands from being "loved to death?" (Amy Christopherson, College Teacher, Sherri's former student)
Answer Hi Amy! This trip is truly wonderful. The Ecuadorian government is doing a wonderful of protecting the Galapagos Islands and its natural treasures. They have enacted very tough laws restricting human population encroachment. The laws protecting wildlife and the islands themselves are being enforced and with any luck, we will all have the Galapagos and its wildlife treasures for centuries to come. It would be a great vacation for you and your family!!
Question How do you think this experience will help your teaching skills? (J. Karshner, High School Student)
Answer This experience, as well as all my past field experiences, will enrich my teaching skills beyond imagination. It provides an opportunity for young people to learn about science through the eyes of someone close to them. I would like to think that it encourages my students to go out into the field themselves. My philosophy is that there is much more to science and learning in general than that which can be found between the pages of a crusty, old textbook.
Question Are there any snakes in Galapagos? If so, what kind, and are they venomous? (Greg Henry, Middle School Teacher)
Answer There are three species of Galapagos snakes, in the genus Alsophis. They are all endemic and all are constrictors. None of them is poisonous.
Question You talked (in the video segment of your journal) about frequent eruptions that shape the land of the Galapagos Islands. I was wondering if the animals inhabiting the island are devastated by the frequent eruptions? Can they sense and eruption and save themselves, like birds before a storm? (Erin Waldner, High School Student)
Answer It is impossible for us to know exactly how devastating the frequent and sometimes violent eruptions of the Galapagos vocanoes have been to wildlife over the long run. More recently, while there have been some large eruptions, no single species has been completely devastated by such occurrences. A greater threat to wildlife here, as is true worldwide, is the encroachment of humans.
Question My biology students are keeping track of your field trip in a log book/field guide. We have a nautical chart of the islands and wonder if possible can the following information be relayed each day in the Journal:
  1. Lat. and Long. position of ship
  2. Meteorological data: as much as possible!! like sea/air temp. wind speed/dir., rel. humidity, currents etc.!
We are looking at the pages on La Nina/El Nino and trying to learn about these and the cause/effects on the biological life where you are right now. Great Expedition! Look forward to getting the reports. Thanks for help. (Clive Tattersall, Strong Vincent High School, Erie, PA 16502.)
Answer Our latitude / longitude here in Galapagos: 89-92 degrees W; we will be right on the equator, and moving only about 1 degree N and S in our travels to different islands within the Galapagos Archipeligo.The Sea Temperature is 72 degrees; air temperature is 71 degrees (21.5 C)

El Nino has heavily impacted the islands wildlife: For example, the marine iguana had approximately 70 percent mortality (death rate) as a result of an increase in water temperature of only 3.5 degrees F. The warming of the water caused a catastrophic loss in the algae from which the marine iguanas get most of their nutrient. In some animals, like the boobies, El Nino actually helped the species!
Question Who discovered the Galapagos Islands? What was the date of the discovery? (Brittany, Middle School Student)
Answer In 1535, Frey Thomas de Berlanga, a bishop of Panama, discovered the Galapagos; however, some historians maintain that early Incas discovered the islands even earlier. The bishop was sailing from Panama to what is now Peru when he found these islands. When he wrote of his discovery to Carlos V of Spain, he described in detail the giant tortoises and the giant iguanas. His expedition turned out to be somewhat ill-fated, since they had no fresh water, and two of his crew died.
Question I was wondering if you have seen any of the Galapagos Hawks yet? How big are they? What does their diet consist of? How much do they weigh? (Tim Kloer, College Student, Colorado State University)
Answer No, I haven't seen any hawks here, but Galapagos has some of the most interesting and diverse bird species on Earth. The blue-footed boobies are my personal favorites, they're pretty goofy acting. It sort of reminds me of being back home in my Biology class! The birds here are all uniquely adapted to their ecological niches. The finches, sometimes called Darwin's finches, are a perfect example of this. One finch, the woodpecker finch, uses a small twig, which it grasps with its bill, and pokes holes into bark to retrieve grubs. I guess you can add the woodpecker finch to the list of other animals, such as chimps, who are known to use tools!
Question How did you feel when you first saw the Galapagos? (Asena, Middle School Student)
Answer I was impressed by the dramatic landscape of this unique ecosystem. It is one of the most beautiful places I have ever been. The first animal I saw was a brown pelican, which is one of my favorite birds.
Question What encouraged you to make this scientific journey? Is the expedition dangerous? (Erin Primavera, Middle School Teacher)
Answer I have always loved wild places and wildlife. I have traveled all over the world to see and learn about our Earth's precious natural treasures. I believe the more we learn, the better we are able to protect our fragile Earth and all her wonders. Anytime you are in nature's wild areas, there is the possibility of something going wrong; but, that is true of anything you do. I feel much safer with animals and in natural environments than I do in big cities.
Question What made you want to become involved in science? Do you like animals? Cause I've heard a lot of people say that played a large part in why they are scientists. I like animals a lot and I could never do what you are doing! Good luck! (Sarah Scott)
Answer I love wildlife, it has become my life's work to learn about wild creatures and how I can help protect them. A very wonderful and famous scientist, Dr. Jane Goodall, has played a tremendous role in encouraging me to become involved in conservation and science. And yes, Sarah, you can do this too!
Question In what ways are humans impacting the Galapagos Islands? (KaSandra and Rachael)
Answer Human are impacting by introducing alien species, such as dogs and pigs, which prey upon sea bird eggs and other wildlife. They also create pollution and destroy natural habitats.


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.