DESC Challenge: Earn a Planet Earth DVD

For the past few nights I have been staying up late to watch Planet Earth via Discovery HD on demand and last night I watched the first episode, Pole to Pole, again for the fourth time.  There were so many connections to content in Science Connection that I had to share a favorite.

When you watch Pole to Pole, you really see how dependent other animals are on each other.  You also see how they physically change the landscape in which they live.  In Science Connection, there is a great interactive exploration called "The BIG Role of Hippopotami."  The exploration (which can be done by students individually, in groups, or as a whole class) shows how the Nile Hippopotamus is a "keystone species" with very critical links in its habitat. 

So, here’s a challenge for you and your students…
Log in to DESC (click here if you need a passcode) and try out the exploration (The BIG Role of Hippopotami).  When you successfully complete the exploration, you will be posed with a question. 

Post a comment to this blog entry that answers that question.  I will send the DVD of Pole to Pole to the first three DEs who post a really good comment.  "Really good" will be determined using my internal rubric 🙂 


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  1. Alison Oswald-Keene said:

    I was truly impressed with the exploration, “The BIG Role of Hippopotamus”. In working through the exploration, the information presented, as well as the final question, are very thought provoking. The Hippos have such a deep tie to their environments, in so many ways, that it would be fair to say that if the Hippo populations were to decline due to illegal hunting, there would be devestating consequences. The plankton population would decline due to the loss of nutrients from the dung in the waters. Fish populations in the areas would decrease which would effect the human populations and other animal species. While some species might increase for a while,populations and landscapes will be severly changed by the illegal hunting.
    I really liked the question as it was posed, it will allow my students to spend time in conversation to be able to come up with a response which they can support with facts and details.

  2. Michele Futch said:

    It was awesome. The interactive website and the links are incredible. I can’t wait to sign up for the webinar to share with my students!

  3. Michele Futch said:

    I got so excited about reading about the Planet Earth webinar info with the link to this blog, that I forgot to answer the question. SORRY!

    Illegal hunting can lead to waning population of hippos and other species. The decreasing population can greatly change and alter the plant cycles, water cycles, and other criteria that make the Earth as it should be.

  4. Marie Coleman said:

    What a great learning activity! I liked the connection to standards, the interaction with the content, and the ‘what if’ thinking question!

    As a keystone species, the hippo plays an especially interdependent role with other species and its environment. With the unnatural loss of hippos via illegal hunting, warthogs would have a more difficult time getting to water (trench digging), there would be a decrease of fish population for the people to eat and market (dung to increase aquatic nutrients), and the red-billed oxpecker would suffer from food and protection loss (mutual symbiotic relationship).

    So what other species play such a big role in our environment? Beavers, prairie dogs, sea otters and starfish … and even humans! Though perhaps not a keystone species, this leads to further conversation about the loss of other important species, i.e., honey bees and how that will impact our food production, etc. – what a wonderfully interdependent world we live in! =)

  5. Holly Porter said:

    Just as the comment states, predicting what might happen in such complex ecosystems is hard to fathom.
    Initially, the loss of hippopotami in the ecosystem would mean a loss of nutrients returned to the aquatic environment. Hippopotami are, as it said, the keystone species of the Nile and a major contributor to the growth of phytoplankton and algae. This decline of crucial “food” will decrease the size of the fish and the quantity of fish available for other animals and people.
    Also, a decrease in the hippos will cause the oxpeckers to struggle with other oxpeckers for the right to continue their mutualistic partnership with the remaining hippopotami.
    Eventually, the channels created by the trips back and forth from the water would fill with sediment and vegetation, decreasing the overall size of the wetlands. A decrease in the size of the wetlands would certainly affect the warthogs and other animals trying to get to the water.
    The lack of overly grazed areas by the hippopotami would begin to cause the grasses and small non-woody plants to overpower the more delicate and more desirable plants. This would affect diets of several herbivores including the gazelles.
    Again, the true level harm that would occur with the illegal hunting of hippos would be hard to measure, but no doubt vast and definitely visible.

  6. Halcyonica said:

    I’ve heard so much about the Planet Earth series, but I haven’t seen it yet. I can’t wait! It looks sooo good!

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