Crow is the common name for the forty-five species within the genus Corvus. All crows within this genus have primarily black feathers, although many species have additional colors in their plumage.
These birds are on every continent except South America and Antarctica. Their ability to solve problems and use tools makes them one of the most intelligent animals in the world. They can also recognize people they consider dangerous and those they think are friendly.
Like many birds, crows are monogamous, often mating for life. However, they are promiscuous, like many other bird species that are socially monogamous. Extra-pair copulations occur and may lead to males raising offspring that are not their own.
Often, these extra-pair copulations result from unmated males with high levels of testosterone finding unprotected females sitting on a nest with her eggs or hatchlings. Unmated males will attempt to mate with the female while she often stays still to protect her young.
All crows are socially monogamous and often live cooperatively within large family groups of offspring raised in different years. These cooperative families help to ensure nest success because older siblings help raise their younger siblings.
When Do Crows Mate?
Female crows begin mating at around three years old, while males start breeding at about five years of age. In some species, individuals may delay breeding and continue living with their parents and siblings.
Depending on the latitude, climate, and species, the timing of the breeding season varies. On average, American Crows begin their breeding season in April. The Pied Crow in Africa nests between September and November, depending on the latitude.
Many crow species live in forests and are often secretive about their mating and nesting habits. As a result, researchers have not yet studied their breeding habits extensively, and little is known about when these species mate.
How Do Crows Mate?
Like many birds, male crows attract females using a courtship ritual. The crow courtship ritual involves males showing off their flying abilities, singing complex songs, and bringing food gifts to females.
Once a female accepts a male after their courtship, they spend time together and bond by being affectionate. Crows show affection by nuzzling each other and flying together, and it is part of how they maintain their lifelong relationship.
When it is time to fertilize the eggs, male crows copulate with females by standing on their backs and rubbing their cloacas together.
Male crows, unlike ducks, lack a penis to aid in fertilization and must rub their cloaca against the female’s cloaca for several seconds to transfer sperm.
How Often Do Crows Mate?
The number of times a crow breeds during the year depends on the latitude at which the crows live. In the northern latitudes, crows only produce offspring once per year and typically lay their eggs in the spring.
Crows can produce two broods annually in more tropical climates, laying their eggs around April and then again in September or October. Each female lays between three and nine eggs which she incubates for about two and half weeks.
The baby crows fledge around one month after hatching and then hang out with their family, working cooperatively for many months or years afterward. Each brood successfully produces an average of three crows that survive to adulthood.
What Happens if a Crow Loses Its Mate?
If a crow loses its mate, it will try to find a new mate. While crows do not spend time mourning their lost mate, researchers have observed funerary rituals in some crow species when they found a dead crow.
When a crow finds a dead crow, it will call out to other crows nearby, and they gather around the corpse. This gathering can be significant and last around fifteen to twenty minutes while the birds create a lot of noise before they eventually disperse.
Researchers believe this funeral gathering might be a way to ascertain the cause of death and evaluate potential dangers to other birds. If they see the dead crow associated with a person or some food source, they will associate that person or food with death.
Additionally, some birds poke at the corpse, seeming to investigate it. Others react aggressively toward the dead bird, attacking it. A small percentage react sexually toward the dead bird and attempt to copulate with the corpse.
Do Crows Mate With Other Species?
Because all crows are in the genus Corvus, they are closely related to one another. Crows from different species will cross-breed and produce hybrid offspring, which can then produce viable offspring.
In some parts of the world, especially in Europe, closely related species crossbreed. Research efforts to better understand the life history of crows, particularly Carrion and Hooded crows, have found hybridization within these species.
The climate during previous ice ages caused some species to diverge genetically. With current climate trends and retreating ice, many species have started to merge genetically, resulting in taxonomic confusion.
