This section of the book is from the "Stories of Animal Sagacity" book, by William Henry Giles Kingston.
Two blackbirds had built their nest in the thick bough of a tree which overhung a high paling. Here they fancied themselves secure from the prying eyes of idle boys or marauding cats. The hen laid her eggs in her new abode, and in due time several fledgelings were hatched, which her faithful mate assisted her to rear. While in the full enjoyment of their happiness, watching over their helpless young ones, they one day saw what to them appeared a terrific monster—a large cat—leap to the top of the paling, and begin cautiously creeping along it. So narrow was it, however, that even Grimalkin could not venture to move fast.
The parent blackbirds watched him with beating hearts as he crept on and on, his savage eyes turned up ever and anon when he stepped towards their nest, where their young ones were chirping merrily, unconscious of danger. In another instant he might make his fatal spring, and seize them in his cruel jaws. The heart of the tender mother urged her to risk her own life for the sake of her offspring. Downward she flew, uttering loud screams of anger almost within reach of the marauder, but the narrowness of the paling prevented him from leaping forward and seizing her in his claws. The brave father was not behind his mate in courage. He too pitched on the top of the fence directly in front of Grimalkin. As the cat crept on he retreated, hoping to draw her past his nest; but the cruel plunderer’s eye was too securely fixed on that. The cock, seeing this, darted with the courage of despair on the back of his enemy, and assailed him with such fierce and repeated pecks on the head, that the cat, losing his balance, fell to the ground, and, astonished at the unexpected attack, scampered off, resolved, I hope, never again to molest the heroic blackbirds; while they flew back to the nest they had so bravely defended.