Birds that feed on nectar are called nectarivores. The most common nectar-feeding bird is the hummingbird. Hummingbirds have long beaks and tongues that allow them to access nectar deep within flowers. Other birds that get some or all of their energy from nectar include sunbirds, honeyeaters, and lorikeets.
Why do some birds feed on nectar?
Nectar is an attractive food source for birds because it provides a concentrated source of energy in the form of sugars. It takes a lot of energy for birds to fly, so nectar gives hummingbirds and other nectar feeders quick fuel. Nectar is produced by plants to attract pollinators. When birds access nectar, they get coated in pollen which they then transfer to other flowers, leading to pollination. So feeding on nectar benefits both the birds and the plants.
Adaptations for nectar feeding
Hummingbirds and other nectarivores have specialized physical adaptations that allow them to obtain nectar.
- Long, slim beaks to access nectar at the base of long or slender flowers
- Tongues with fringed, forked tips to lap up nectar
- High metabolisms and fast heart rates to power flight and process all that sugar
These adaptations allow nectar-feeding birds to thrive on the nectar resources produced by various flowering plants.
Types of nectar-feeding birds
Hummingbirds
Hummingbirds are the most specialized nectar feeders. There are over 300 different hummingbird species found only in the Americas. A few characteristics of hummingbirds:
- Small size – ranging from 2.5 to 8.5 inches long
- Fast flapping wing speed enabling hovering and even backwards flight
- Long beaks for probing into flowers
- Extendible tongues with forked tips for drinking nectar
- Preference for red tubular flowers which matches their adaptations
- Aggressive behavior around flowers to chase off competition
- High metabolism requiring frequent feeding
Hummingbirds get most of their energy from nectar and defend flower territories aggressively. They will also eat small insects for protein. A lack of hummingbird pollination can have negative impacts on ecosystems dependent on them.
Sunbirds
Sunbirds are a family of small passerine birds found in Africa, Asia and Australia. There are over 100 species of sunbirds which exhibit similar ecology and behavior to hummingbirds. Sunbird characteristics include:
- Slim, curved beaks for nectar feeding
- Brush-tipped tongues to collect nectar
- Small size – 4 to 8 inches long
- Metallic or iridescent plumage
- High speed wing beats while feeding
- Help pollinate flowers, important ecosystem service
Though not closely related, sunbirds fill an ecological niche similar to hummingbirds in the Old World. They are important pollinators of native plants and help support local ecosystem health.
Honeyeaters
Honeyeaters comprise a large family of small passerines found in Australia and New Guinea. There are over 180 species in this family showing a range of dependence on nectar. Key traits include:
- Long, slender, curved beaks
- Brush-tipped tongues for collecting nectar
- Many species have bright yellow, orange, red plumage
- High pitched vocalizations
- Take nectar and pollen from flowers
- Also eat insects, fruit, and other small prey
Honeyeaters play an important role as pollinators in Australasia. They help pollinate native trees like eucalyptus, mistletoe, and banksia. Loss of honeyeater populations can impact ecosystem functioning.
Lorikeets
Lorikeets are a group of small to medium sized parrots found in Australia, southeast Asia, and the south Pacific. They are brightly colored, active, noisy birds that feed mainly on nectar, pollen, and fruit. Traits of lorikeets include:
- Small-medium size from 5 to 15 inches long
- Slender curved beaks adapted for nectar feeding
- Special brushy tongues for gathering nectar and pollen
- Brightly colored plumage – blue, green, orange, yellow
- Travel together in noisy flocks
- Help pollinate trees and flowering plants
Lorikeets are important pollinators and seed dispersers in Australia and Oceania. Their populations are threatened by habitat loss, competition with invasive species, and capture for the pet trade.
Flowers pollinated by nectar-feeding birds
Nectar-feeding birds coevolved with many flowering plants that rely on them for pollination. Here are some common flowers pollinated by nectar birds:
Flower | Bird Pollinators | Region |
---|---|---|
Hibiscus | Hummingbirds, honeycreepers | Americas |
Eucalyptus | Lorikeets, honeyeaters | Australia |
Aloe | Sunbirds | Africa |
Banksia | Honeyeaters, lorikeets | Australia |
Puya | Hummingbirds | Americas |
As this table shows, different groups of nectar birds pollinate flowers native to their regions. Disruptions to these pollination relationships can negatively impact ecosystem health.
Behavior while feeding on nectar
Nectar-feeding birds exhibit some specialized behaviors to access flower nectar:
Aggression and Territory Defense
Hummingbirds, sunbirds, and honeyeaters aggressively defend flower territories. They dive bomb, vocalize, and chase off intruders. This ensures they get adequate nectar to meet their high metabolic needs.
Flower Specialization
Many nectar birds like hummingbirds have preferred flower types – often red tubular flowers matching their beak shape. This flower consistency likely improves foraging efficiency.
Rapid Feeding
Hummingbirds can lick nectar up to 20 times per second. Their tongues have forked tips that efficiently lap up nectar. Sunbirds also feed at rapid speeds, enabling efficient nectar intake.
Energy Management
Nectar birds need to enter an energy-saving torpor at night to conserve energy between feeding bouts. They lower body temperature and heart rate to reduce energy use when not active.
Flying Backwards
Hummingbirds are the only birds able to fly backwards. This allows them to get into the right position to access nectar while hovering at flowers.
These behaviors reflect adaptations enabling nectar birds to thrive on abundant but dispersed nectar sources in their environment.
Threats facing nectar-feeding birds
Some key threats facing hummingbirds, sunbirds, honeyeaters and other nectar-feeding birds include:
Habitat Loss
Destruction of forests, grasslands, and scrublands removes critical feeding and nesting habitat for nectar birds. For example, logging of eucalyptus removes a key nectar source for lorikeets in Australia.
Invasive Species
Introduced species compete for limited nectar resources. For example, invasive Argentine ants protect aphids on flowers, restricting hummingbird access to nectar sources.
Pesticides
Chemical pesticides can poison nectar sources and kill the insects that birds feed on. Neonicotinoids may harm bee and bird populations by contaminating pollen and nectar.
Climate Change
Changing climate disrupts timing of flower blooming and nectar availability. Mismatch between flower and bird populations reduces feeding opportunities.
Disease
Diseases like avian malaria carried by introduced mosquitoes are linked to population declines of Hawaiian honeycreepers. Outbreaks may increase with climate change.
Protecting critical habitat and reducing pesticide use can help conserve threatened nectar-feeding bird populations.
The importance of nectar birds
Nectar-feeding birds provide essential ecosystem services:
Pollination
Hummingbirds, sunbirds, honeyeaters and lorikeets pollinate wildflowers and economically valuable crops. Nectar birds maintain healthy, productive ecosystems.
Seed Dispersal
By feeding on fruit, nectar birds disperse seeds for many native plants. This facilitates plant reproduction and landscape restoration.
Pest Control
Nectar birds consume insects attracted to flowers, reducing crop pests and controlling insect populations.
Ecotourism
Birdwatchers spend millions viewing spectacular nectar-feeding birds like hummingbirds. This provides jobs and economic incentives for conservation.
Protecting nectar bird habitat ensures healthy, functioning ecosystems benefitting both wildlife and people.
Conclusion
Nectar-feeding birds like hummingbirds, sunbirds, honeyeaters and lorikeets have specialized adaptations enabling them to access energy-rich nectar. This mutualistic relationship benefits both the birds and the plants they pollinate. However, nectar birds face threats from habitat loss, invasive species, pesticides, climate change and disease. Conservation measures focused on protecting critical habitat and food sources can help ensure thriving populations of these essential pollinators and beautiful birds.