During the breeding season, many songbirds begin their dawn chorus well before sleepy campers crawl out of their tents. But if you hear a bird singing loudly (perhaps annoyingly) in the middle of the night, it’s likely to be the northern mockingbird. Skilled mimics, mockingbirds put together long, complex songs by combining imitations of other bird species (and sometimes non-avian sounds). The birds continue adding new sounds to their repertoires as long as they live. Males, which sing more often and louder than females, may learn some 200 different songs during their lives.
Eavesdropping Iguanas Use Mockingbird Calls To Survive
by Jason G. Goldman
Predator-prey interactions are often viewed as evolutionary arms races; while predators improve their hunting behaviors and their ability to sneak up on their prey, the prey improve upon their abilities to detect and escape from their predators.
The problem, of course, is that there is a trade-off between maintaining vigilance – the attention necessary to be consistently aware of others in the environment takes quite a bit of physical and mental energy – and doing all the other things that an animal must do, such as finding its own food. As a result of this trade-off, many social species, especially mammalian and avian species, have developed alarm calls. Alarm calls are specific vocalizations that signal the presence of a danger in the environment to nearby conspecifics, and sometimes contain additional information about the type of threat or predator.
Subsequent to the introduction of predatory birds, howler monkeys on Barro Colorado Island near Panama rapidly developed an alarm call specific for those birds that indicated the presence of an avian predator: something like “danger from above!” They did not merely adapt an already existing alarm call to the new predator, they developed an entirely new one…
The males establish a nesting territory in early February. If a female enters his territory, the male will pursue the female with initial aggressive calls and, if she becomes uninterested, with softer calls. Northern Mockingbirds tend to be monogamous, and the female may return to the same male from the previous season.
Both the male and female are involved in the nest building. The male does most of the work, while the female perches on the shrub or tree where the nest is being built to watch for predators. The nest is built approx. 3 - 10 feet above the ground. The outer part of the nest is composed of twigs, while the inner part is lined with grasses, dead leaves, moss or artificial fibers. The eggs are a light blue or greenish color and speckled with dots. Three to five eggs are laid by the female, and she incubates them for nearly two weeks. Once the eggs are hatched, both the male and female feed the chicks.
The birds aggressively defend their nest and surrounding area against other birds and animals. When a predator is persistent, mockingbirds from neighboring territories, summoned by a distinct call, may join the attack…
Mockingbirds (Mimus polyglottos), parent and chicks
Once they reach a certain size, baby Mockingbirds will jump out of the nest and live on the ground (usually in areas with vegetative cover). The parents will guard and care for them there until they are fully capable of flying. They will severely harass any predators that come near.
If you want to help birds like Mockingbirds and Blue Jays (in North America), that care for their young on the ground (as well as ground nesting birds)…