# DBT JRF 2020 — Question 12

Exam: DBT JRF 2020 · Section: A · Topic: Ecology · Difficulty: Medium

## Question

The fruit of a particular tree species formed the predominant diet of the dodo. After the dodo became extinct, that tree species also became extinct. Which of the following is the most likely cause for the tree's extinction?

## Options

- **A.** the dodo habitat was destroyed
- **B.** the seeds of that tree required passage through the digestive system of the dodo for germination
- **C.** by living close to the tree, the dodo protected the tree from other birds
- **D.** other birds ate the fruit of that tree, as well as fruit of other trees, and dispersed more seeds than the dodo did

## Answer

Option B

## Explanation

The dodo (Raphus cucullatus) was the exclusive agent for seed dispersal and germination of Calvaria major (tambalacoque tree) on Mauritius. The hard endocarp of Calvaria seeds required abrasion by the dodo's muscular gizzard (mechanical scarification) to thin the seed coat sufficiently for germination. After dodo extinction (~1681), no new Calvaria trees germinated for nearly 300 years. Stanley Temple (1977) famously demonstrated this by feeding seeds to turkeys — the abraded seeds germinated. This is a classic example of an obligate mutualism/co-extinction cascade.

Source: https://mypyqbuddy.com/questions/the-fruit-of-a-particular-tree-species-formed-6a05a8a02adafec4702931f2