Dunnock system can be shifted from one that favours female success (polyandry), to one that promotes male success (monogamy, polygynandry, or polygyny). The dunnock builds a neat nest (predominantly from twigs and moss and lined with soft materials such as wool or feathers), low in a bush or conifer, where adults typically lay three to five unspotted blue eggs. Broods, depending on the population, can be raised by a lone female, multiple females with the part-time help of a male, multiple females with full-time help by a male, or by multiple females and multiple males. In pairs, the male and the
Common black hawk distinctive piping "spink-speenk-speenk-spink-spink-spink". The common black hawk is protected in the far north of its range (in the USA) under the Migratory Bird Treaty Act of 1918. Common black hawk The common black hawk ("Buteogallus anthracinus") is a bird of prey in the family Accipitridae, which also includes the eagles, hawks, and Old World vultures. It formerly included the Cuban black-hawk ("Buteogallus gundlachii") as a subspecies. The mangrove black hawk, traditionally considered a distinct species, is now generally considered a subspecies, "B. a. subtilis", of the common black-hawk. The adult common black-hawk is long and weighs on average. It has