The poet says that these cubs could be the last ones ever to freely live and mate because they might get extinct.
In the poem, the poet tries to mention the danger that some animals are facing.
The poet mentions about a tigress from the East who is sad while giving birth to her cubs. She is afraid that these cubs might only be the last one from their kind.
The excessive extinction of animals due to human hunting is the reason that these cubs could be the last ones.