Birds-of-paradise are known for their elaborate courtship displays and rituals. The males use their bright colorful plumage and unique dance moves to attract potential mates. There are around 40 different species of birds-of-paradise, most of which are found in New Guinea. Each species has its own distinct courtship routine.
Some quick facts about the courtship rituals of birds-of-paradise:
– Courtship displays are important for mate selection. Females will choose a male based on the quality of his dance and plumage.
– Displays involve combinations of visual and vocal signaling. Males will fan out feathers, hop, skip, dance, sing, etc.
– Displays take place at communal leks where many males gather to attract females.
– Some displays incorporate the use of props like sticks, fruits, and insects.
– Displays are energetically costly and demonstrate a male’s strength and health.
– Younger males typically stay on the outskirts of leks watching and learning from older males.
Lek Courtship
The courtship process for most birds-of-paradise starts at lek sites. A lek is an area where males of a species gather and compete to attract females. Leks are typically open areas near food sources that allow females to easily observe prospective mates. 10-20 males may attend a given lek site on a daily basis during breeding season.
At the lek, each male clears out his own small display court from which he performs his courtship dances when females arrive. The males stand in their courts facing towards the center of the lek. When a female approaches, the males initiate their displays. The quality of the display, plumage, and vigor reflects male fitness.
Younger subordinate males with less impressive plumage usually linger at the edges of the lek observing the dominant males. This allows them to practice and perfect their own display techniques in hopes of gaining a central court during future seasons.
Display Types
There are two main categories of avian courtship displays: stationary dances and aerial displays.
Stationary Dances
Stationary dances involve a repetitive sequence of moves by a male who stays centered in his display court. The stationary dances of birds-of-paradise involve combinations of sounds, plumage manipulations, and stylized movements or poses. Here are some examples:
– The magnificent bird-of-paradise has a distinctive stationary hopping dance during which it makes pi-pi-pi alarm calls.
– King birds-of-paradise vibrate their wings and shout during stationary displays.
– Standardwing birds-of-paradise point their iridescent blue wing shields towards females.
– The red bird-of-paradise unfurls its head wire feathers into a cape-like form.
– Wilson’s bird-of-paradise lifts one foot behind its back while fanning its cape and head filaments.
– Ribbon-tailed astrapia males gyrate their tails in precise patterns.
Species | Stationary Display Description |
---|---|
Magnificent | Hopping dance with pi-pi-pi calls |
King | Wing vibration and shouting |
Standardwing | Pointing blue wing shields |
Red | Unfurling head wire feathers |
Wilson’s | Foot lift while fanning cape |
Ribbon-tailed astrapia | Precise tail gyrations |
Aerial Displays
Aerial displays involve flying maneuvers and dives rather than stationary dancing. These displays demonstrate a male’s strong flying capabilities. Some examples:
– Lesser birds-of-paradise have swooping flights where they make loud calls.
– Twelve-wired birds-of-paradise beat their wings over their heads to make mechanical sounds.
– Parotia males make buzzing sounds in dive displays.
– King of Saxony birds-of-paradise hover in front of females while orienting their head plumes towards them.
Species | Aerial Display Description |
---|---|
Lesser | Swooping flight with loud calls |
Twelve-wired | Wing beating over head |
Parotia | Buzzing dives |
King of Saxony | Hovering with head plume displays |
Plumage Ornaments
Male birds-of-paradise have evolved incredibly ornate plumes and feathers to impress females. Here are some of the unique features different species display during courtship:
– **Wire feathers** – thin feathers resembling wire that can be moved and posed. Found on species like the red bird-of-paradise.
– **Capes** – broad cape-like feathers extending from the chest. Seen in Wilson’s bird-of-paradise.
– **Filaments** – fleshy strands extending from the head. Displayed by greater lophorina males.
– **Tail wires** – flank plumes and long tail wires in species like the superb bird-of-paradise.
– **Head fans** – broad erectile fan of feathers on the head. Twelve-wired birds-of-paradise have striking head fans.
– **Breast shields** – iridescent breast shields made of modified feathers. Seen in species like Lawes’s parotia.
– **Head plumes** – long ornamental head plumes like in the King of Saxony bird-of-paradise.
Plumage Type | Description | Example Species |
---|---|---|
Wire feathers | Thin, wire-like feathers | Red bird-of-paradise |
Capes | Broad chest cape feathers | Wilson’s bird-of-paradise |
Filaments | Fleshy head strands | Greater lophorina |
Tail wires | Long flank and tail plumes | Superb bird-of-paradise |
Head fans | Erectile head feather fans | Twelve-wired bird-of-paradise |
Breast shields | Iridescent chest feathers | Lawes’s parotia |
Head plumes | Ornamental head feathers | King of Saxony |
Vocalizations
Along with visual displays, vocalizations are an important part of avian courtship. The male songs and calls are specific to each species. Songs can relay information about the male’s fitness. Some examples of courtship vocalizations include:
– Booming sounds made by inflating neck airsacs. The curl-crested manucode makes deep booms.
– Trumpet sounds produced through specialized trumpet-like feathers. Trumpet manucodes vocalize this way.
– Whirring or buzzing noises generated by vibrating feathers and membranes. Twelve-wired birds-of-paradise make mechanical whirrs.
– Popping sounds created by snapping wing tendons. Spotted catbirds make popping wing calls.
– Courtship songs and calls unique to each species like the sea green cacique’s screeching call.
Display Props
Some birds-of-paradise incorporate props into their displays. This includes items held in the beak or things that are part of modified court grounds. Examples include:
– **Fruits and fungi** – Some manucodes offer colorful fruits and fungi they gather from the rainforest to females.
– **Insects** – Parotia males hold large insects like phasmids as part of their display rituals. The insects serve as gifts.
– **Modified display courts** – Satin bowerbirds build and decorate stick structure “bowers” in their court areas.
– **Sticks and twigs** – Decorated stick avenues are built by species like the MacGregor’s bowerbird.
– **Specially cleared courts** – ground courts are cleared of debris by sweeping with wings and beaks. Some add white saliva decorations.
Prop Type | Description | Example Species |
---|---|---|
Fruits and fungi | Gifts of rainforest produce | Manucodes |
Insects | Gifts of large insects | Parotia |
Bowers | Stick display structures | Satin bowerbird |
Twig avenues | Display decoration | MacGregor’s bowerbird |
Saliva markings | White saliva court markings | Spotted catbird |
Mating and Fertilization
After observing and evaluating prospective mates, the female will select a male and copulation will occur. However, courtship rituals continue and intensify after mating occurs to ensure the female is ready for fertilization.
Post-copulation displays help stimulate the female physiologically for fertilization. Displays and mating will repeat numerous times over a period of days or weeks before fertilization finally takes place.
During this time females continue to assess males to determine if re-mating with a different male is preferable. Males work hard to keep impressing females during this period with their displays and offerings.
Parental Investment
Among birds-of-paradise, females provide all parental care while males provide for courtship and mating only.
After fertilization occurs, females will build a nest, incubate eggs, and raise young alone. The nests are usually shallow cups built high in trees. Clutches are typically just 1-2 eggs. Incubation lasts around 3 weeks.
The chicks are helpless at birth and rely fully on the female parent for food, protection, and care. Chicks fledge from the nest around 2-3 weeks after hatching. Males take no part in parental duties.
Evolution of Courtship Displays
The courtship rituals and plumage of birds-of-paradise have evolved over time via sexual selection pressures. Females choose males with the most attractive displays that demonstrate fitness and quality.
Preference drives the evolution of ever more elaborate plumage ornaments, display behaviors, and courtship tactics in males over successive generations. This leads to ritual and physical excess.
Sexual selection has led to male-male competition through improved courtship performance. It has also led to female choice of mates with the best presentations. These mating preferences continue exaggerated trait evolution.
Displaying in Hybrid Zones
Regions where two closely related bird-of-paradise species interbreed and hybridize are called hybrid zones. In these areas, male displays can take on an intermediate form between what is typical of both parental species.
For example, in hybrid zones between greater and lesser birds-of-paradise, males may show elements of display postures and calls from each species. This demonstrates the heritability of the ritualized displays.
Females show mating preferences for purebred males over hybrids in such zones. This demonstrates strong sexual selection pressure for species-typical signaling for attracting conspecific mates. Hybrids have reduced fitness and viability.
Significance of Courtship Rituals
The courtship rituals of birds-of-paradise serve a few key functions:
– **Attract Mates** – The main purpose of courtship displays is to visually and audibly attract potential female mates. More attractive displays signal male quality.
– **Assess Fitness** – Displays allow females to assess male health, strength, and viability as a breeding partner. Flashier displays may indicate better fitness.
– **Stimulate Females** – Displays encourage female reproductive receptiveness and prepare them physiologically for mating/fertilization.
– **Deter Rivals** – Displays also ward off rival males from the best display courts and signal dominance.
– **Reinforce Species Boundaries** – Species-specific display traits prevent unfit hybrid matings between closely related species.
Threats and Conservation
Habitat loss from deforestation poses the greatest threat to various birds-of-paradise species. Climate change and introduced species also endanger some birds-of-paradise.
Logging and agricultural development destroys their rainforest habitats and interrupts courtship rituals. Lek breeding is especially impacted if display sites are compromised.
Targeted conservation efforts are needed to protect crucial rainforest breeding areas. Captive breeding programs may help some endangered species like the Bali myna. Public education can also promote conservation.
Conclusion
Birds-of-paradise are renowned for their ostentatious courtship performances full of visual and vocal signaling. Stationary dances, aerial displays, plumage and vocal adaptations, and display props all work together to attract potential mates. Females select males with the best displays and strongest fitness cues to breed with. These courtship rituals are driven by strong sexual selection and mate choice preferences that lead to the evolution of ever greater display elaborations over time. Conservation of courtship habitat is crucial for preserving these iconic avian mating spectacles.