Category Archives: Amazing Amazon Teasers – Answers

Answers to the teaser questions with explanations, sources and links to graphics and more information.

Amazon Biodiversity Teaser #3 – Answer

Question: Which type of animal could have an ecological impact on the abundance and diversity of the Amazon rain forest?

Answer Choices: A) Fish B) Snakes C) Frogs D) Butterflies

Correct Answer: A) Fish

Summary: Seed dispersers are crucial players in any forest ecosystem. Seed dispersal studies have traditionally focused on species of birds, bats, monkeys and rodents, but a new study by Jill T. Anderson of Duke University suggests that there could be a correlation between the populations of large fruit-eating Amazonian fish and the abundance and diversity of certain tree species in the Amazon rain forest. The fish involved in the study are the tambaqui and the pirapitinga (photo), both known as pacu fish, are massive fruit-eating fish that live in the Amazon River and its tributaries. The tambaqui have an average weight of about 33 pounds and the much larger pirapitinga are an average of 200 pounds each. These fish are classified as long-distance dispersers. They eat the seeds of trees that drop into the water and later drop them in a new place along the river. These fish are being overexploited by local fisherman and in turn the species are dropping in population. Dr. Anderson explains that a drop in these species’ populations could result in less abundance and diversity in the Amazon rain forest.

Source: FAO Non-Wood News 23rd Edition; Giant fish help the Amazon rain forest grow; November 2011;

Amazon Environment Teaser #2 – Answer

Question: The Amazon forest biomass is a source for how many tons of carbon?

Answer Choices: A) 5 billion B) 10 billion C) 50 billion D) 100 billion;

Correct Answer: D) 100 billion tons

Summary: The 3,130,386 square miles of total rain forest in the Amazon make up a staggering 54% of the planet’s remaining tropical rain forests. Deforestation accounts for a considerable portion of annual carbon loss from the Amazon. The whole Amazon rain forest biomass contains 100 billion tons of carbon which is the same amount of global fossil-fuel emissions from over a 10 year period. To put this number in perspective, 100 billion tons of rain forest biomass is equivalent to the weight of 500 million Boeing 747 airplanes. Comparatively, all of the tropical rain forests of the world contain 229 billion tons of carbon in their vegetation combined. Today, there has been considerable conversation about increasing carbon emissions worldwide. The Woods Hole Research Center has determined that deforestation in all of the world’s tropical rain forests emitted 1.14 billion tons of carbon per year into the atmosphere and the net carbon loss from deforestation in the Amazon was about 350 million tons per year. This makes Amazonian deforestation account for 30.7% of all global carbon emissions due to tropical deforestation. The potential effects from an increase in Amazonian deforestation on carbon emissions could be extremely significant on a global scale. In the 1980’s the Amazon rain forest was considered a carbon sink, where carbon was accumulated and stored. However, there has been a shift in the Amazon that now classifies it as a carbon source where it is emitting more carbon than it is absorbing. Maintaining the integrity of the Amazon rain forest will need a better understanding of the vulnerability and resilience of the transitioning forest ecosystem.

Source: Eric Davidson et al., “The Amazon basin in transition,” Nature, 19 January 2012.;
A. Baccini et al. “Estimated carbon dioxide emissions from tropical deforestation improved by carbon-density maps.” Nature Climate Change, 29 January 2012;

Amazon Geography Teaser #7 – Answer

Question: The Amazon River accounts for what percentage of all fresh water entering the world’s oceans?

Answer Choices: A) 5% B) 10% C) 15% D) 20%

Correct Answer: D) 20%

Summary: On average, the Amazon River discharges about 1,300 cubic miles per year (that’s about 6 million cubic feet per second). This number is higher than the combined discharges of the next eight largest rivers, by volume. The United States’ largest river, the Mississippi, only discharges about 75 cubic miles per year. The peak of discharge for the Amazon comes between the months of November and March, during which the river can discharge up to 500 billion cubic feet of water into the Atlantic Ocean. This is comparable to the freshwater needs of all of New York City for nine whole years! This is also the same as filling the 102 floors of the Empire State Building with water and pouring it into the Atlantic… 13,500 times! Also, during the high water season, the mouth of the Amazon can be up to 300 miles wide, which is about the distance from Philadelphia, PA to Boston, MA.

Source: Monga Bay, Rhett Butler;;
USGS, Earth’s water: Rivers and streams;

Amazon Geography Teaser #6 – Answer

Question: Which do you believe is the longest river in the world?

Answer Choices: A) Nile River B) Yangtze River C) Mississippi River D) Amazon River

Correct Answer: D) the Amazon River

Summary: Approximations of the length of the Amazon River usually fall between 3,900 miles and 4,100 miles. However, a recent study by Brazilian researchers has proposed a new source for the Amazon River on Mount Mismi in southern Peru which would make the Amazon River the longest river in the world at 4,250 miles. The Nile would be the next longest and is believed to be 4,160 miles long. The new proposed length could be contested and it is likely that there are many scientists who won’t agree but for the time being the Amazon is believed to be the longest river in the world. In addition to this length, about 1,100 tributaries of varying length and volume merge with the Amazon River at different locales. These rivers provide freshwater, food, and transportation routes for the many inhabitants of the region, both human and animal. One of the most astonishing features of the Amazon River system is the “Meeting of Waters” located where the dark Rio Negro meets the silty Amazon River. Overall, the rivers that flow through the Amazon Basin account for almost one-fifth of all free-flowing fresh water on earth. See the online source listed below for the whole article and maps showing the proposed new source.

A portion of the Kayapo River, an Amazon River tributary.

Source: Monga Bay; NASA maps newly proposed source of the Amazon River; July 3, 2007;

Amazon Geography Teaser #5 – Answer

Question: Only a few thousand years ago, rain forests, like the Amazon, covered what percent of the Earth’s surface?

Answer Choices: A) 6% B) 11% C) 14% D) 21%

Correct Answer: C) 14%

Summary: Tropical rain forests, like the Amazon, get there name because of their geographical location in the Inter-Tropical Convergence Zone (ITCZ) between the Tropic of Cancer and the Tropic of Capricorn. The air within this zone rises and warms very rapidly, causing an abundance of rainfall. This significant amount of rainfall allows the many species of plants and animals to thrive in the Amazon. It is believed that only a few thousand years ago tropical rain forests once covered 14% of the Earth’s surface. However, massive exploitation of the forests with activities like logging, mining, agriculture and ranching have led to massive deforestation and the loss of many of the world’s tropical rain forests. Currently, tropical rain forests cover about 7% of the earth’s surface. See a map of the distribution of the earth’s rain forests HERE.

Source: Michael Evans, Rainforests,; 27 April 2011;

Amazon Environment Teaser #1 – Answer

Question: Between 1990 and 2000, what was the average rate (mi²/yr.) of total forest area loss in the Amazon?

Answer Choices: A) -5,907 mi²/yr. B) -8,455 mi²/yr. C) -11,008 mi²/yr. D) -13,343 mi²/yr.

Correct Answer: D) -13,343 mi²/yr.

Summary: The World Wildlife Fund predicts that, at current deforestation rates, we could expect to see about 55% of all of the Amazon’s rainforests completely gone by 2030. According to the Forestry Department of the Food and Agriculture Organization of the United Nations (FAO), just over 13,000 square miles of Amazon rainforest was lost per year in the 1990’s. Loss rates are subject to fluctuation due to economic and conservation policies and programs. Many rainforests, like the Amazon, are not managed in accordance with the Forest Principles adopted by the United Nations in 1992. This problem stems from developing countries not having adequate funds and human resources for the implementation and monitoring of these forest management programs. The Amazon rainforests are being demolished for agriculture and cattle ranching, mining projects, road and dam construction, and illegal logging. These activities are being carried out with unsustainable methods stabilizing and possibly increasing the rates of deforestation throughout the region and leading to more and more landscape and river degradation. Climate change has also become a factor in recent decades adding to the many threats that the Amazon faces.

Sources: World Wildlife Fund; Amazon: World’s largest tropical rain forest and river basin;; Food and Agriculture Organization of the United Nations; Global Forest Resources Assessment 2000;

Amazon Biodiversity Teaser #2 – Answer

Question: The Amazon Basin contains what percentage of known species (plants and animals) on Earth?

Answer Choices: A) 1% B) 10% C) 20% D) 45%

Correct Answer: B) 10%

Summary: The Amazon Basin is abundant in biodiversity. The number of known species on earth that have been formally identified is about 2 million species, making the Amazon home to about 200,000 of these. This includes roughly 40,000 plant species, 3,000 freshwater fish species and more than 370 reptile species. However, estimates for the total number of species on earth range between 5 million and 30 million. These extremely large estimates exist because of multiple studies that have been done in the Amazon rainforest that suggest there could be many, many more species on earth than previously believed. Perhaps the most significant study on this topic was conducted by Terry Erwin, a biologist that specializes in beetle populations. In the Amazon, Erwin sprayed pesticides into the forest canopy which caused any insect to fall to the forest floor (see picture here). After examining the fallen insects, he found a high number of undescribed species, as well as over 1,100 species of beetles alone from the canopy of a single species of tree (L. seemannii). Using the Amazon as an illustration for what could be living in other rainforests, he has estimated that the total number of species in the world could be much larger than the meager two million already identified. This leaves plenty of unidentified, “mystery” species that are still out there, many possibly living within the Amazon.

Sources: World Wildlife Fund; Amazon: World’s largest tropical rain forest and river basin;;
The Environmental Literacy Council; How many species are there?;;
Terry Erwin; Tropical forest canopies, the last biotic frontier; 1983; Bulletin of the Entomological Society of America.