Seeing a pair of animals mating indicates a birth in the family of the dreamer or news of some birthday.
Dream dictionary: Mating dream meanings
…Dreaming of doves mating and building their nests, represents peacefulness of the world and joyous homes where children render obedience, and mercy is extended to all. In the dream to hear the lonely, mournful voice of a dove, portends sorrow and disappointment through the death of one to whom you looked for aid. Often it portends the death of a father. To see a dead dove in the dream, is ominous of a separation of husband and wife, either through death or infidelity. To see white doves, denotes bountiful harvests and the utmost confidence in the loyalty of friends. Dreaming of seeing a flock of white doves, denotes peaceful, innocent pleasures, and fortunate developments in the future. If one brings you a letter, tidings of a pleasant nature from absent friends is intimated, also a lovers’ reconciliation is denoted. If the dove seems exhausted, a note of sadness will…
…Dreaming that you see a registered letter, foretells that some money matters will disrupt long-established relations. For a young woman Dreaming that she receives such a letter, intimates that she will be offered a competency, but it will not be on strictly legal, or moral grounds | others may play towards her a dishonorable part. To the lover, this bears heavy presentments of disagreeable mating. His sweetheart will covet other gifts than his own. Dreaming of an anonymous letter, denotes that you will receive injury from an unsuspected source. To write one, foretells that you will be jealous of a rival, whom you admit to be your superior. Dreaming of getting letters bearing unpleasant news, denotes difficulties or illness. If the news is of a joyous character, you will have many things to be thankful for. If the letter is affectionate, but is written on green, or colored, paper,…