The fruit of a particular tree species formed the predominant diet of the dodo. After dodo became extinct,
that tree species also became extinct. Which of the following is the most likely cause for the tree’s
extinction?
1. the dodo habitat was destroyed
2. the seeds of that tree required passage through the digestive system of the dodo for germination
3. by living close to the tree, the dodo protected the tree from other birds
4. other birds ate the fruit of that tree, as well as fruit of other trees, and dispersed more seeds than the dodo
did

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The Dodo and the Vanishing Tree: A Story of Ecological Interdependence

In one of the most intriguing cases of co-extinction, the disappearance of the dodo bird is thought to have led to the extinction of a specific tree species. But what caused this strange outcome?

Let’s look at the common multiple-choice question:

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Why did the tree species go extinct after the dodo?

1. The dodo habitat was destroyed

2. The seeds of that tree required passage through the digestive system of the dodo for germination

3. By living close to the tree, the dodo protected the tree from other birds

4. Other birds ate the fruit of that tree, as well as fruit of other trees, and dispersed more seeds than the dodo did

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Why Option 2 Is Correct:

The dodo bird (which went extinct in the late 1600s) had a mutualistic relationship with a certain tree species, believed to be the Tambalacoque tree (Sideroxylon grandiflorum). Here’s what scientists believe:

• The seeds of the tree had a very tough coating.

• When dodos ate the fruit, the seeds passed through their digestive tract, which softened the seed coat through mechanical and chemical digestion.

• This process enabled the seeds to germinate successfully.

• After the dodo became extinct, no other animal could perform this same role effectively.

 As a result, the tree gradually stopped reproducing and began to disappear — a possible case of co-extinction.

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Why the Other Options Are Incorrect:

• 1. The dodo habitat was destroyed
   While habitat destruction may have played a role in the dodo’s extinction, it doesn’t explain the loss of the tree, which relied on the dodo for seed germination.

• 3. The dodo protected the tree from other birds
   There’s no evidence that the dodo acted as a protector. The relationship was based on seed dispersal and germination, not defense.

• 4. Other birds dispersed more seeds than the dodo did
   If other birds were more effective seed dispersers, the tree would have continued to thrive. But they didn’t help in germination, which is the key issue.

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Conclusion: A Case of Co-Extinction and Ecological Dependence

The extinction of the dodo is a powerful example of how species are interlinked. In this case, the dodo wasn’t just a fruit eater — it was a critical agent of seed germination for a tree species. Without it, the tree couldn’t reproduce and eventually faced extinction too.

This case highlights the importance of preserving biodiversity, because the loss of one species can ripple through entire ecosystems.