Have you ever wondered how birds mate? With so many common bird species living in urban areas, it is not unusual to see birds trying to mate during the springtime.
Watching a male bird trying to mount and balance on his mate looks quite messy and awkward, so how do birds reproduce successfully from this unusual breeding behaviour?
It All Starts with Courtship
Just like for us humans, ladies need to be romanced. The male has to woo his partner and show her that he is worth her attention.
Courtship begins in early spring when the days grow long, the weather is mild and food is abundant. It is the perfect time for breeding and rearing young.
There are many different types of courtship display, but the male is always the one to display and the female chooses.
Feather displays are the most common form of courtship. However, some species prefer elaborate dances or shows of craftmanship via nest building.
Fun fact: Male lyrebirds sing 4 different songs with matching dance movements.
Often, the period of courtship lasts several days, while the physical act of mating is just a few brief seconds. The effort a male puts into his courtship display shows the female his health and strength. These are important qualities for females as it means any future offspring will have a better chance of survival. Females do not pick males with dull plumage or weak courtship dances.
Peacocks’ Splendid Colours
Peafowl are perhaps the most famous birds to use colour for courting. Peahens (females) are a mottled brown colour with blue or green feather crowns on the top of the head.
In stark contrast, peacocks (males) are a vibrant iridescent blue, with contrasting mottled brown wings, orange primary feathers along the wing edge and bright white face markings. The ace up the sleeve for peacocks is their fabulously ornated tail.
Fun fact: Each feather on a peacock’s tail can be as long as 1.5 metres!
At rest, the tail is held closed and trails behind the male like a bride’s dress train. When the male wants to display to a female or warn off a nearby male, he opens his tail like a fan.
A peacock’s tail arcs from either side of their body and is covered in dozens of yellow, green and blue ovals that look like eyes.
Moving on to a different bird species, the red-capped manakin of Central and South America has perhaps one of the most bizarre courtship rituals. It can be considered the bird equivalent of a human singles bar.
A male manakin will choose a long branch to best show off his dance moves so that nearby females can see him in full glory. He will then ‘moonwalk’ back and forth along the branch using tiny leg and feet movements. Their bright red head, black body and sunshine yellow legs only add to the unique display.
Competition for females is so fierce, that only the alpha or higher-ranking males will be chosen by the females. Male manakins practice their moves throughout the year to give themselves a better chance at finding a mate.
Fascinating Nest Builders
No bird species is a better nest builder than the bowerbird. Males will spend days constructing an impressive nest structure called a bower. He will use twigs, grasses and leaves to create the nests. Then he will decorate his bower with brightly coloured objects such as feathers, flower petals or even objects left behind by humans.
A female will inspect a male’s nest, where he will dance for her and even give her one of his bright bower decorations in an effort to impress her.
Some Birds Mate for Life
Most birds will mate with a different partner each breeding season, but many species are monogamous and mate for life:
- Barn owls
- Sandhill cranes
- Bald eagle
Most bird species that mate for life are larger and therefore, brooding and rearing chicks takes far longer. Remaining with the same partner each year is beneficial as it removes the need to find and court a new mate.
Birds that mate for life also share parental duties such as sitting on the eggs, finding food and protecting the nest from predators.
Also Read: What Do Bluebirds Eat?
How Do Birds Mate? – The Cloaca Organ
Once a female has chosen her partner, the pair will engage in short mating sessions. Birds do not have sexual reproductive organs like other animals such as mammals. Instead, both males and females have an opening called a cloaca, which serves to eliminate reproductive fluids, as well as urine and faeces.
During the breeding season, a bird’s cloaca will become swollen. A male will mount his partner and attempt to balance on her back.
Fun fact: Great bustard females will inspect a male’s cloaca to determine his health.
To make access easier for the male, a female will bow her head so her rear end is raised and tuck her tail to one side. The pair then rub their cloaca together to transfer the male’s sperm into the female’s cloacal chamber.
Inside the chamber, a female releases an ovum. If the male’s sperm fertilises the ovum, it will develop into an egg.
An embryonic disc, appearing as a tiny white dot, rests on the yolk of the egg. This is what will develop into a chick. Depending on the species of bird, the process of egg development can be as short as 2 weeks or as long as a month. Chicken eggs hatch within 21 days, whereas penguin eggs take around 35 days to hatch.
Environment Adaptation Means Waterfowl Mate Differently
Bird species such as ducks, geese and swans have a slightly different cloaca than land birds and mate in a similar way to mammals. Their cloaca is extended and is referred to as a phallus. It is a short penis formed by the extended walls of the cloaca.
During mating, a male will insert his phallus into the female’s cloaca, similar to mammalian mating. This is an adaptive advantage, as the sperm is less likely to be washed away by the water.
Most duck species use behaviours such as head bobbing during courtship, with a male and female pairing mimicking one another. Males may also raise their tail feathers and whistle to nearby females, as well as short bursts of swimming with the head held low and outstretched on the surface of the water. Ducks pair for one breeding season and do not return to the same partner the following year.
Geese and swans mate for life, with the female choosing her partner and the pair breeding together every year. Individuals will only choose a new partner if one of the pair dies.