Imperial pigeon facts for kids

Kids Encyclopedia Facts

Quick facts for kids Imperial pigeon

Purple-tailed imperial pigeon (Ducula rufigaster), found in New Guinea
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Columbiformes
Family:	Columbidae
Subfamily:	Ptilinopinae
Genus:	*Ducula* Hodgson, 1836

Ducula is a group of birds in the pigeon family, called imperial pigeons. They are large to very large pigeons with strong bodies and tails that can be medium or long. These birds live in trees and mostly eat fruit. They are closely related to another group of fruit-eating doves called Ptilinopus.

Both Ducula and Ptilinopus pigeons have bright feathers. Their colors are often green, with purple, orange, or red on their undersides. Some Ducula pigeons have a noticeably swollen cere, which is a fleshy part at the base of their beak. They have large mouths and swallow seeds whole. This helps them spread seeds, which is very important for forests.

Imperial pigeons live in forests in southern Asia, New Guinea, northern Australia, and the Pacific islands. Many species move around a lot. They travel long distances to find fruit when it's in season. Some even migrate, flying far away. All imperial pigeons are strong fliers. Sadly, many Ducula species are in danger because their homes are disappearing and predators hunt them.

What Are Imperial Pigeons?
Appearance
- Different Types of Imperial Pigeons
Where They Live and Their Home
Behaviour
- Diet
- Reproduction
- Voice
- Migration
Ecology and Conservation
Species List
Images for kids
See also

What Are Imperial Pigeons?

The name Ducula was first used in 1836 by an English scientist named Brian Houghton Hodgson. He named a pigeon Ducula insignis, which is now known as a type of mountain imperial pigeon. The name Ducula comes from a Latin word meaning "leader."

Scientists are still working to fully understand how all imperial pigeon species are related. There are about 34 to 41 different species of Ducula pigeons. A scientist named Derek Goodwin grouped 36 species into 7 main types in 1959. This grouping is still often used today.

Appearance

Imperial pigeons are large birds. They are usually about 35 to 45 centimeters (14 to 18 inches) long. They have medium to long tails. The Marquesan imperial pigeon is about 50 centimeters (20 inches) long. It is the biggest pigeon that lives in trees.

Pigeons in warm, tropical areas often have many different colors. This helps them recognize each other. Imperial pigeons usually have dark backs and wings, which can be grey or shiny green. Their chests are lighter, ranging from grey to orange, pink, or dark grey. Birds living on islands often have fewer bright markings. Most species look very similar, whether they are male or female.

Some imperial pigeons, like the Pied imperial pigeon, have special feathers called fat quills. These feathers produce a oily substance. This substance is used like oil from a preen gland, which birds use to keep their feathers clean. When the pied imperial pigeon preens with this yellow oil, its head and shoulders can turn from cream to yellow. Scientists are still trying to figure out why these fat quills exist. They might be a signal to other pigeons, help fight germs, or even have a smell that pigeons can detect.

Different Types of Imperial Pigeons

There are many different groups of imperial pigeons, often named after where they live or how they look.

Poliocephala species-group: These four species live in the Philippines and Sulawesi. They all have a light band across their tail and green or purple backs. The Pink-bellied imperial pigeon and White-bellied imperial pigeon are similar. The Mindoro imperial pigeon and Grey-headed imperial pigeon are also alike, but different in size.
Carola species-group: The Spotted imperial pigeon is smaller and has a shorter, spotted tail. It lives in the same area as some Poliocephala pigeons, suggesting they are related.
Aenea species-group: This large group includes the Green imperial pigeon. These birds have shiny green, purple, or bronze upper parts. They are found across Asia and the Pacific. This group is further divided into smaller types.
- Some Asian species have shiny green backs and pink heads.
- The pacifica subgroup has six species found across the Pacific. They are similar but have larger ceres (the fleshy part at the base of the beak).
- The finschii subgroup has four species, mostly found on islands near New Guinea.
- Another subgroup includes the Pink-headed imperial pigeon and others, which have less shiny upper parts.
Brenchleyi species-group: This group includes four types of large, dark, chestnut-bellied pigeons. They are found across the Western Pacific islands. The Pinon's imperial pigeon and Collared imperial pigeon live in New Guinea. The Bismarck imperial pigeon is found on the Bismarck Archipelago.
Zoe's imperial pigeon: The Zoe's imperial pigeon from Indonesia and New Guinea is so unique in color that it has its own group.
Badia species group: This group includes the Mountain imperial pigeon and Dark-backed imperial pigeon, which are found in many places from Indian subcontinent to Malaysia. The Timor imperial pigeon is a similar grey pigeon found in Timor.
Bicolor species-group: These are large white pigeons with black wingtips. They live in New Guinea, its islands, and northern Australia. The Pied imperial pigeon, Silver-tipped imperial pigeon, and Torresian imperial pigeon are part of this group. Scientists sometimes disagree on whether these are separate species or just different types of the same species.

It can be hard for scientists to decide if two types of pigeons are different species. This is because there isn't much information about how they behave or if they can breed together.

Where They Live and Their Home

Imperial pigeons are found only in southern Asia, Australia, New Guinea, and the Pacific. They live from the Himalayas to Tahiti. Most types of these birds live in New Guinea. Imperial pigeons are strong fliers. They can fly over oceans and have successfully moved to many islands.

Australia doesn't have many types of Ducula pigeons. Only one species, the Torresian imperial pigeon, breeds on the mainland. Scientists aren't sure why more species didn't cross to mainland Australia.

Imperial pigeons live in trees. They are found almost only in forests and woodlands where there are fruit trees. About half of the species live in mountain forests, up to 2500 meters (8,200 feet) high. Many live on islands in coastal forests. A few species live at the edges of forests or in mangrove swamps.

Behaviour

Scientists don't know a lot about most Ducula species. Many are shy and live in remote areas, making them hard to watch. Their breeding and nesting habits are not well studied. Even though they are large and can be many, these birds can be hard to spot because they feed quietly deep in the leaves.

Imperial pigeons move around a lot. They can fly long distances to find fruit. They are strong fliers and can fly between islands to find food sources that appear at different times. Small islands might not have enough food all the time, but they can be a temporary stop for these traveling birds. Some pigeons fly more than 32 kilometers (20 miles) daily from their island roosts to the mainland to feed.

Some species live alone or in pairs. But many are very social and form flocks of 30 to 50 birds. Pied imperial pigeons like to breed on offshore islands or in mangroves. The Torresian imperial pigeon forms huge groups on the Queensland coast in Australia. They fly to fruit forests during the day and sleep together at night. One island hosted 20,000 to 25,000 birds during breeding seasons in the 1970s. In 2014, a similar number of over 22,000 birds were counted.

Pigeons drink water by sucking it up with their beaks continuously in the water. Fruit-eating pigeons might get a lot of water from their food, so they may not need to drink as much as other pigeons.

Diet

Imperial pigeons live in forests and mangroves. These places provide seasonal fruits from tropical trees, palms, vines, and bushes. Most birds climb through branches, sometimes hanging upside down, to reach fruit. They twist the fruit off with their beak and swallow it whole. They can open their mouths very wide, up to 40 millimeters (1.6 inches), to swallow large fruits. The Marquesan imperial pigeon can swallow seeds as big as 70 millimeters (2.8 inches). They might also eat flowers, leaves, and insects.

Unlike pigeons that eat seeds, Ducula pigeons have thin-walled stomachs and short, wide guts. This allows large seeds to pass through their bodies. After they digest the fruit's flesh, they poop out the seeds whole. This makes them very important for spreading seeds and helping new plants grow.

Other types of pigeons have grinding stomachs that destroy seeds or make them throw up larger seeds. Imperial pigeons are among the largest fruit-eating animals in the forest. They can spread seeds from fruits that are too big for most other animals to handle. Fruits larger than 30 millimeters (1.2 inches) can only be eaten by large birds like hornbills and Ducula pigeons. For example, Pacific imperial pigeons are excellent seed dispersers in Tonga. They are very important for keeping forests healthy in their homes.

Reproduction

Imperial pigeons build simple nests from loosely woven twigs. They usually place these nests in the fork of a tree. Species that live in mangroves build stronger nests from mangrove shoots. They usually lay only one egg. The egg hatches fairly quickly. Both the male and female pigeons share the job of sitting on the egg and caring for the baby birds.

Like most pigeons, Ducula pigeons produce a special food called Crop milk. This is a thick, cheesy substance that comes from their crop (a part of their throat). Both male and female pigeons make this milk. It helps the baby birds grow very fast and leave the nest quickly, which makes them less vulnerable to danger. Their breeding cycle is short, so they can raise several groups of babies during the long summer breeding season.

Crop milk is full of fats, proteins, and enzymes. It also helps transfer helpful things from the parent to the baby, similar to how mammals pass on antibodies. Making crop milk is controlled by a hormone called prolactin.

Having plenty of fruit is very important for fruit-eating birds to have successful babies. Large groups of breeding pigeons need untouched forests to provide enough fruit trees for them to eat every day.

Voice

The sounds imperial pigeons make vary between species. Some make typical "coo" and "coo-woo" sounds like other pigeons. Others have deep, booming calls, abrupt barking notes, or two-part booming calls.

Migration

Pigeons are generally strong fliers and good at moving to new places. They can fly across oceans to find fruit when it's in season. Some imperial pigeons, like the Pied imperial pigeon, migrate partly. This means they move depending on where food is available.

Ecology and Conservation

About one-third of all pigeon species in the world are endangered. This makes the pigeon family one of the most threatened bird families. Asia, Australia, and Oceania are home to nearly two-thirds of all pigeon species, but three-quarters of those species are in danger.

The biggest dangers to pigeons are losing their homes, hunting by people, and new predators that are not native to the area. Other threats include diseases and possible competition from species that have been introduced. Large groups of Ducula pigeons can move around and use big areas for food. However, they are still in danger when large parts of forests are destroyed.

People hunt pigeons for food and sport. Hunting of the Torresian imperial pigeon in Australia has reduced their numbers. Hunting for food is still a problem in Asia and the Pacific because pigeons are a good source of protein. Historically, when humans settled in new areas, it often led to birds becoming extinct.

Many Ducula species live on forested islands in the Indian Ocean, Southeast Asian islands, and Pacific islands. Island species are especially vulnerable. They are highly specialized and not prepared for new predators like cats, rats, and stoats.

One of the most endangered Ducula species is the Marquesan imperial pigeon. Its numbers dropped from 250 birds in 1998 to fewer than 100 in 2000. Programs have started to move these birds to more islands to help them breed.

Fruit-eating pigeons are very important for spreading seeds. This helps keep tropical forests diverse and healthy. If too many pigeons are lost, it can harm the plants and animals in a region. This is especially true when logging clears large areas that need to grow back.