Question

Abingation tortoises in Galapagos Islands become extinct after goats with great browsing efficiency were introduced. It is an example of
(a)Competitive release
(b)Co-existence
(c)Interference competition
(d)Competitive exclusion

Answer 1

Hint: It is sometimes referred to as Gause’s Law and explains about leaving out of some specific species from its dominating area upon the introduction of new species.

Complete answer:
The competitive exclusion principle is defined as the removal or exclusion of the existing species on the occurrence of a new species in an area of the existing species when competing for limited resources on which both species depend.
In the given question, tortoises greatly depended upon the grass of the Galapagos Islands for their food. On the introduction of goats, the goats competed in their eating habits with the tortoises and consumed the grasses more rapidly than the tortoises. As a result, there was less food available for the tortoises to eat and they slowly died out of hunger and became extinct.

Additional Information:
 -Competitive release occurs when one of the competing species is removed as a result of the invasion of a better-adapted species, competing for the same resource, so that the other competitors of the first species can now fully use the resources which they were unable to use in the presence of the first species.
-Co-existence occurs when the two competing species, Competing for the same resource manage to live together, within the same locality.
-Interference competition is the completion between the species of the same or other species in the form of aggression. Example: rivalry or fight between two individuals of the same species for habitat.
So, the correct answer is, ‘competitive exclusion.’

Note: In case of competition exclusion one of competing species always has more advantage than that of the other species. The competitive exclusion principle was given by Georgy Gause.