Sunbird

Sunbirds build purse-shaped nests often hung from branches with side entrances with porch-like awnings. The birds commonly decorate or hold together their nests with spider webs. They are called sunbirds because of the bright red, orange, and yellow plumage on their undersides.

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Passeriformes

Family: Nectariniidae

Genus: Various (see below)

Species: Various (see below)

Over 150 species of sunbirds are organized into 16 genera in the Nectariniidae family. Male sunbirds have bright, iridescent, blue and green plumage (feathering) on their back sides contrasting their bright yellow, orange, and red chests and stomachs. Iridescent means the colors are shiny, metallic, and reflect light. Bright yellow or red tufts appear on the wings of some males when they display their wings to females. Females are usually duller olive-green, gray, and brown with tinges of yellow on their underparts and some streaks or spots. The smallest sunbirds are only three to four inches (7 to 10 centimeters) long. Larger sunbirds like spiderhunters in the genus Arachnothera may reach 8 3/4 inches (22 centimeters) long and weigh 1 1/3 to 1 3/4 ounces (38 1/2 to 49 grams). This includes their long, central tail feathers which are one-third of the birds' total length and are of various styles.

The sunbirds live in many habitats, including lowland forests, gardens, moorlands, thorn scrub, and rhododendron forests. Most build purse-shaped nests in secure locations or suspended from branches. The nests have porch-like awnings over the side entrances. The birds often decorate their nests with spider webs or wrap the webs around the nests to hold them together. Spiderhunters build cup-shaped nests that do not hang. Sunbird species live in Africa, the Middle East, New Guinea, Australia, Southeast Asia, and China. They are most densely populated near the equator. Colorful birds live in the open, while plainly colored species live in shady forests. The spider-hunters live in Malaysia. Sunbird calls are sharp and metallic or loud, high-pitched, fast, and tinkling.

Sunbirds eat flower nectar, fruit, insects, and spiders. The size and style of their bills determine which flowers and insects the birds eat. The birds with small and short bills forage in the foliage for insects, which they grasp with the edges of their bills. The edges are finely serrated, or jagged, like the blade of a bread knife or a saw. They also pierce with their bills the bases of flowers which insects pollinate and sip small amounts of nectar. Other species with larger, longer, thinner, and curved bills can draw the pollen from larger flowers with their tubular, split-tipped tongues. Sunbirds use their strong feet, short toes, and sharp claws to perch near the flowers instead of hovering like hummingbirds. In addition to mistletoe, many flowers depend on the sunbirds for pollination. Mistletoe flowers may explode open and spray the birds with pollen when they visit the flowers. Older birds may duck to avoid the spray, while younger birds often get covered with the pollen. Sunbirds have flaps called opercula that cover their nostrils to keep out the pollen. Sunbirds are often territorial and chase other birds from food sources. However, they may gather in common feeding areas with many flowers but rarely form lasting flocks. Searching for food, they are nomadic, or wandering. Some species mix with other bird species at feeding grounds.

Mating and nesting seasons depend on the rainfall and how much food is available. Some species breed year-round, and pairs may nest five times in a breeding season. Sunbirds are monogamous, meaning one male and female mate only with each other. During the mating season, sunbirds may be very pugnacious, fighting and quarreling with other birds. The male does not help build the nest or incubate the eggs, but he feeds his mate while she incubates the eggs in the nest. He defends flowers nearby so he can provide her with enough food. The female lays two to four white or bluish-white eggs with heavy, dark spots and streaks. The young hatch after 14 to 15 days. She protects and feeds the young for another two to three weeks. This time is called nestling, after which the birds fledge, or are ready to fly and leave the nest.

Natural predators include snakes, lizards, and birds of prey. Other threats to the birds are unknown.

The lifespan of most sunbirds is 2 to 8 years, though some, like the Amethyst or black sunbird (Chalcomitra amethystina), live for up to 16 years.

Many sunbirds have large populations, but some species have limited ranges and decreasing populations. The Loveridge's sunbird (Cinnyris loveridgei), Amani sunbird (Hedydipna pallidigaster), and elegant sunbird (Aethopyga duyvenbodei) are endangered. The Banded Sunbird (Anthreptes rubritorques), the Rockefeller's Sunbird (Cinnyris rockefelleri), and the Rufous-winged Sunbird (Cinnyris rufipennis) are vulnerable with decreasing populations. The primary threat to sunbird populations is human activities causing habitat destruction.

Species include:

Amani sunbird Hedydipna pallidigaster

Giant sunbird Dreptes thomensis

Golden-winged sunbird Drepanorhynchus reichenowi

Johanna's sunbird Cinnyris johannae

Palestine sunbird Cinnyris osea

Purple sunbird Cinnyris asiaticus

Regal sunbird Cinnyris regius

Scarlet-chested sunbird Chalcomitra senegalensis

Scarlet-tufted malachite sunbird Nectarinia johnstoni

Splendid sunbird Cinnyris coccinigastrus

Superb sunbird Cinnyris superbus

Tacazze sunbird Nectarinia tacazze

Variable or yellow-bellied sunbird Cinnyris venustus

Bibliography

"Beautiful Sunbird." San Diego Zoo Wildlife Alliance, animals.sandiegozoo.org/animals/beautiful-sunbird. Accessed 15 May 2024.

"Nectariniidae - Sunbirds, Spiderhunters." PBS, nhpbs.org/wild/Nectariniidae.asp. Accessed 15 May 2024.

Winkler, D. W., et al. "Sunbirds and Spiderhunters (Nectariniidae)." Birds of the World, Cornell Lab of Ornithology, 2020, birdsoftheworld.org/bow/species/nectar1/cur/introduction. Accessed 15 May 2024.