2014 · Q112
In a forest, animals like voles and wood lice feed on plant roots and barks respectively. Among the other carnivores, foxes, shrews and owls are present in that forest. Following predictions are made by a group of observers who have visited the forest :
- 1If the roots of the tree develop a disease, then voles and foxes will starve and not the owls.
- 2Population of voles is dependent on wood lice population through food web.
- 3If owl population declines, it will indirectly affect wood lice population.
- 4If barks of tree are affected due to a disease, then reduction of wood lice will affect the shrew population forcing owls to eat more voles.
Which of the above predictions is/are correct?
General KnowledgeBiology
- A1, 2 and 4
- B2 only
- C1 and 2 only
- D3
Explanation
Only prediction 3 holds: fewer owls trigger a trophic cascade that indirectly affects wood lice. Owls also eat voles (1 wrong), voles and wood lice occupy different niches (2 wrong), and shrews' insectivory would not force owls onto voles (4 wrong).