Ornithophily

Transfer of pollen grains by birds is known as ornithophily.

• Birds visit flowers mainly to feed on nectar.
• While feeding, the body or beak of the bird comes in contact with pollen grains.
• Pollen sticks to the bird and is carried to another flower.
• When the bird touches the stigma of the next flower, pollination takes place.
• This usually promotes cross-pollination, which helps in genetic variation.

Common Pollinating Birds:

• Sunbirds
• Hummingbirds
• Honey thrushes and other nectar-feeding birds

Common Plant Examples:

• Bombax
• Callistemon (bottle brush)
• Butea
• Erythrina (coral tree)
• Syzygium (rose apple)

Structural and functional adaptations:

1. Bright colours: Flowers are usually bright red, orange, yellow, or blue, making them easily visible to birds from a distance.
2. Large and showy flowers: These flowers are often conspicuous and sturdy enough to attract repeated visits.
3. Tubular, cup-shaped, or urn-shaped form: Floral shape often suits the beak and feeding habit of nectar-feeding birds.
4. Abundant nectar: Flowers secrete a large quantity of nectar to attract birds.
5. Dilute nectar: Nectar is often relatively dilute, which suits many bird pollinators.
6. Sticky pollen grains: Pollen may be sticky so that it adheres easily to the bird's body.
7. Reduced fragrance: These flowers are often not strongly scented because birds rely more on vision than smell.

1. A brightly coloured flower attracts a bird.
2. The bird visits the flower to suck nectar.
3. During feeding, pollen grains stick to the beak, head, or feathers of the bird.
4. The bird flies to another flower of the same species.
5. The pollen touches the stigma, leading to pollination.

Ornithophily

• Ornithophily is the transfer of pollen by birds like sunbirds and hummingbirds; e.g., bombax, callistemon, butea, erythrina, syzygium.
• Birds visit flowers to feed on nectar, and pollen sticks to their beak, head, or feathers and is carried to another flower.
• Touching the stigma of the next flower causes pollination, promoting cross-pollination and genetic variation.
• Ornithophilous flowers are bright (red, orange, yellow, blue), large, showy, and tubular, cup-, or urn-shaped to suit a bird's beak.
• They secrete abundant, dilute nectar, bear sticky pollen, and have reduced fragrance since birds rely on vision more than smell.