Identify the error in the following sentence: (a) Certain animals have a tendency (b) to communicate only with (c) its own species and none other. (d) No error.

The error is in part (c). The subject 'Certain animals' is plural, so the possessive pronoun must also be plural. 'Its' (singular) should be replaced with 'their' (plural). The correct phrase is 'their own species and none other'. This is a pronoun-antecedent agreement error. Parts (a) and (b) are correct.