The Wedge-tailed Eagle: Australia's Majestic Sky Monarch

Wedge-tailed Eagle (Aquila audax) - Image credit: Australian Museum

Introduction

The Wedge-tailed Eagle (Aquila audax) is Australia's undisputed king of the skies. As Australia's largest living bird of prey and one of the largest eagles in the world, this magnificent raptor commands respect with its imposing size, powerful presence, and incredible hunting abilities. With a wingspan exceeding 2.3 meters and the ability to soar to altitudes of 2,000 meters, the Wedge-tailed Eagle is a symbol of power, freedom, and the wild Australian landscape. From Aboriginal Dreamtime stories to modern emblems, this "bold eagle" has captured imaginations for millennia.

Scientific Classification

Scientific Name: Aquila audax
Family: Accipitridae
Genus: Aquila (true eagles)
Common Names: Wedge-tailed Eagle, Eaglehawk

Name Meaning: Aquila audax means "bold eagle" in Latin - a fitting name for this fearless predator that can attack and kill prey as large as adult kangaroos!

Taxonomic Relationships

The Wedge-tailed Eagle is one of 12 species of large, predominantly dark-colored "booted eagles" in the genus Aquilafound worldwide. Genetic research has shown it's closely related to other large Aquila species, particularly:

• Golden Eagle (Aquila chrysaetos)
• Gurney's Eagle
• Imperial Eagles

Subspecies

Two subspecies are recognized, though the separation has been questioned:

A. a. audax (Latham, 1801) - Nominate subspecies

• Found throughout mainland Australia
• Southern New Guinea
• The "typical" Wedge-tailed Eagle

A. a. fleayi (Condon & Amadon, 1954) - Tasmanian subspecies

• Endemic to Tasmania
• Named after Australian naturalist David Fleay
• Larger than mainland eagles
• Particularly outsized talon dimensions
• Deep chocolate brown color (not blackish)
• Whitish-buff nape (not tawny-rufous)
• Paler, sandier juveniles
• Listed federally as Endangered

Physical Description

An Imposing Presence

The Wedge-tailed Eagle is truly massive:

Size:

• Length: 81-106 cm (32-42 inches)
• Wingspan: 182-232 cm (6.0-7.6 feet), maximum recorded 2.84 m (9 ft 4 in)!
• Weight (males): 2.0-4.0 kg (4.4-8.8 lb), average 2.5-3.2 kg
• Weight (females): 3.0-5.8 kg (6.6-12.8 lb), average 4.2-5.3 kg

Comparison: The female Wedge-tailed Eagle is one of the world's largest eagles. Australia's second-largest raptor, the White-bellied Sea-Eagle, is about 15% smaller linearly and 25% lighter!

The Distinctive Wedge Tail

The species' most diagnostic feature is its long, diamond-shaped wedge tail, clearly visible in flight even when the bird soars thousands of meters above the ground. The tail is:

• Long and distinctive
• Wedge-shaped or diamond-shaped
• Characteristic even at great heights
• Unmistakable identification feature

Plumage

Adults:

• Overall dark blackish-brown to glossy black
• Progressive darkening over at least 10 years
• Nape and hind-neck: sandy brown or reddish-brown
• Crown and forehead: black or blackish-brown
• Wing coverts: sandy brown to reddish-brown (forming band across wing)
• Underwing and undertail: blackish
• Female slightly paler than male (only plumage difference between sexes)

Juveniles and Immature Birds:

• Mid-brown color
• Reddish-brown heads and wings
• Golden to reddish-brown ruff around nape
• Much lighter than adults
• Gradually darken over years
• Tasmanian subspecies juveniles are even paler and sandier

Other Physical Features

Wings:

• Long and broad
• Fully feathered
• "Fingered" flight feathers spread like fingers when soaring
• Built for soaring and diving

Legs:

• Completely feathered down to the base of the toes
• Baggy appearance
• Powerful
• Key identifying feature (Sea-Eagles have unfeathered lower legs)

Head and Beak:

• Elongated upper mandible
• Strong, hooked beak
• Bill: pale pink to cream with black tip
• Eyes: brown to dark brown (yellowish-brown in some)
• Bare skin around eye: pinkish, white, or bluish-white
• Small head relative to body size
• Long neck

Feet:

• Off-white to greyish-white
• Large and powerful
• Equipped with formidable talons
• Can lift about 50% of body weight under ideal conditions

Wedge-tailed Eagle showing impressive wingspan - Image credit: Australian Museum

Distribution and Habitat

Geographic Range

The Wedge-tailed Eagle has an extensive range:

• All of mainland Australia
• Tasmania
• Southern New Guinea
• Many offshore islands (Western Australia and elsewhere)

This eagle is found in every Australian state and territory.

Habitat Preferences

The Wedge-tailed Eagle is one of Australia's most generalized birds of prey, found in diverse habitats:

Preferred Habitats:

• Open eucalypt woodlands
• Lightly wooded country
• Open forests with varied topography
• Farmland and agricultural areas
• Plains and grasslands
• Areas with rocky outcrops
• Some open terrain with native woodlots

Altitude Range:

• Sea level to alpine regions
• Mountains up to 2,000 m elevation
• Can soar to altitudes of 2,000 meters!

Generally Avoids:

• Dense rainforests
• Coastal heaths
• Very heavily forested areas

Habitat Requirements:

• Tall trees or elevated structures for nesting
• Good vantage points
• Open hunting grounds
• Sufficient prey availability

Territory Size

Each breeding pair occupies a home range or territory:

• Nests typically 2.5-4 km apart in most years
• Can be less than 1 km apart when conditions are very good
• Territory includes nesting sites (defended aggressively)
• Larger home ranges for hunting (not defended, may overlap with other pairs)

Extraordinary Abilities

Vision

The Wedge-tailed Eagle has remarkable eyesight:

• Binocular vision allows precise depth perception
• Can see 8 times more detail than humans
• Can spot prey from up to 2 kilometers (1.2 miles) away!
• Eyes equipped with nictitating membrane - a third transparent eyelid
• Membrane acts like "safety goggles" when grabbing prey

Flight Capabilities

Soaring Master:

• Soars with ease at great heights
• Can circle effortlessly at 2,000 m altitude
• Uses thermal updrafts for energy-efficient flight
• Flight feathers spread like fingers for control
• Unmistakable silhouette visible from great distances

Hunting Dives:

• Powerful stooping attacks
• Fast, controlled descents
• Impressive aerial maneuverability

Strength

• Can lift approximately 50% of body weight
• Working together, groups can kill prey as large as adult kangaroos
• Powerful talons can crush and kill large prey
• One of the world's most powerful avian predators

Intelligence

• Learn and remember successful hunting grounds
• Coordinate hunting in groups
• Recognize and avoid threats
• Show tactical awareness in attacks
• Cache food for later consumption

Diet and Hunting Behavior

What They Eat

The Wedge-tailed Eagle is a true generalist predator with a diverse diet:

Primary Prey (Live):

• Rabbits and hares (30-92% of diet, usually 30-70%)
• Mammals (usually over 500g):
  • Wallabies and kangaroos (including juveniles)
  • Foxes
  • Young sheep and goats
• Lizards (large species)
• Snakes
• Birds (over 100g)
• Other marsupials

Carrion (Major Food Source):

• Roadkill kangaroos
• Dead livestock
• Other carcasses
• Up to 20 eagles may attend a carcass (though only 2-3 feed at once)

Hunting Strategies

Solo Hunting:

• Hunt from perches (trees, poles, rocky outcrops)
• Soar at height scanning for prey
• Swift diving attacks
• Early morning or late afternoon preferred (cooler temperatures)

Pair Hunting:

• Mates cooperate on larger prey
• Coordinated attacks

Group Hunting:

• Multiple eagles work together
• Can take down adult kangaroos!
• Tactical coordination
• Greater success on large prey

Food Caching:

• Store food items on branches near nest
• Return to cached food later
• Strategic resource management

The Rabbit Boom

The introduction of European rabbits to Australia has been a major boon to Wedge-tailed Eagles:

• Abundant, easily caught prey
• Population increase in eagles
• Rabbits now comprise up to 92% of diet in some areas
• However, calicivirus introduction reducing rabbit populations
• Long-term impact on eagles remains unknown

The Lamb Controversy

Wedge-tailed Eagles have been persecuted for supposedly killing lambs:

• Reality: Lambs make up only a small percentage of diet
• Much of "predation" is actually scavenging already-dead lambs
• Research has established eagles hardly ever kill healthy lambs
• Historical persecution was largely unjustified

Breeding and Nesting

Monogamous for Life

Wedge-tailed Eagles are monogamous and apparently mate for life:

• Form permanent pair bonds
• If one partner dies, survivor finds new mate
• Pairs remain in territory year-round
• Hunt separately but reunite for breeding

Breeding Season

Timing: April to September, mainly July

• Varies by location and year
• Depends on local food availability
• Both parents share all duties

The Massive Nest

Wedge-tailed Eagle nests are engineering marvels:

Construction:

• Large platform of dead sticks
• Built in prominent location with commanding view
• Usually in tallest tree in territory
• Can also use live trees, shrubs, cliff faces, telegraph poles, even ground!
• Shallow cup on top lined with fresh twigs and leaves

Reuse and Growth:

• Reused for years (sometimes decades)
• New material added each year
• Nests grow to enormous size

Impressive Dimensions:

• Can reach 1.8 m across (6 feet)
• Up to 3 m deep (10 feet)
• May weigh 400 kg (880 pounds)!
• Among the largest bird nests in the world

Multiple Nests:

• Pairs may have up to 10 different nests in their territory
• Often use different nests in different years
• Maintain backup nesting sites

Commensal Nesters: Smaller birds like finches sometimes nest in the underside of the huge nest, benefiting from the eagles' protection from predators!

Eggs and Incubation

Clutch Size: 1-3 eggs, usually 2

Egg Appearance:

• White with varying amounts of reddish-brown spots and blotches
• Measure approximately 73 mm x 59 mm

Laying:

• Eggs laid at intervals of 2-4 days
• Incubation starts with first egg
• Results in asynchronous hatching

Incubation:

• Duration: 45 days
• Both parents incubate
• Male does most hunting during this period

Raising Chicks

Hatching:

• Chicks hatch covered in white down
• Hatch at different times due to staggered laying
• First chick larger than second, second larger than third

Siblicide (Cainism):

• Usually only one chick survives per clutch
• Oldest/largest has best survival chance
• In scarce food conditions, oldest chick kills and eats smaller siblings
• In good years, two chicks may successfully fledge

Early Development:

• First 5 weeks: Adults must deliver food to chick's mouth
• After 5 weeks: Chicks recognize food and feed themselves
• Second week: First feathers appear
• Will defend themselves if threatened (adults make little defense)

Fledging:

• Chicks remain in nest for 80-90 days
• Juveniles stay with adults for 11 weeks after leaving nest
• Dependent on parents for up to 6 months after fledging

Dispersal:

• Young and non-breeding birds disperse widely
• Move wherever conditions suitable
• Juveniles known to travel over 850 km in 7-8 months

Maturity:

• Acquire adult plumage at 6-7 years of age
• Sexual maturity reached at 3 years
• Seldom breed before 6-7 years old

Territorial Behavior

Defending Territory

Wedge-tailed Eagles are fiercely territorial:

• Defend nest sites year-round
• Patrol territory boundaries
• Attack intruders with low swoops and dives

Intruders Attacked Include:

• Other Wedge-tailed Eagles
• Other raptors
• Model airplanes
• Hang gliders
• Gliders
• Fixed-wing aircraft
• Helicopters!

Yes, Wedge-tailed Eagles have been known to attack aircraft they perceive as threats to their territory!

Sensitivity to Disturbance

• If disturbed when preparing to lay eggs, may abandon nest
• Sensitive to forestry operations
• Require undisturbed nesting sites
• Human activity can impact breeding success

Conservation Status and Threats

Overall Status

Conservation Status: Least Concern (overall)

Population: Most common of the world's large eagles

However: National population has declined by 28%

Tasmanian Subspecies: Listed as Endangered

Benefits from Human Activity

Wedge-tailed Eagles have benefited from:

• Opening of forests in eastern Australia
• Increased rabbit availability (major food source)
• Agricultural landscapes providing hunting grounds
• Roadkill providing carrion

Major Threats

Historical Persecution: The most devastating impact on Wedge-tailed Eagles:

• Bounties offered for dead eagles
• 147,237 killed in Western Australia (1928-1968)
• 162,430 killed in Queensland (1951-1966)
• Shot and poisoned for supposedly killing lambs
• Population severely declined

Current Threats:

1. Poisoning:

   • Indirect poisoning through dingo baits
   • Pesticides
   • Major ongoing hazard

2. Habitat Loss:

   • Clearing of nesting trees (especially in arid zones)
   • Loss of tall trees for nesting
   • Forestry operations

3. Direct Persecution:

   • Still shot, trapped, and deliberately poisoned in some areas
   • Particularly in Tasmania
   • Farmers who view them as lamb killers

4. Vehicle Strikes:

   • Eagles feeding on roadkill are at grave risk
   • Significant cause of mortality

5. Other Hazards:

   • Electrocution on power lines
   • Collisions with wind turbines
   • Collisions with fences and wires

6. Rabbit Decline:

   • Calicivirus reducing rabbit populations
   • Long-term impact on eagles unknown

Legal Protection

• Fully protected in all Australian states and territories
• Protected under Wildlife Conservation Acts
• Shooting not permitted
• Official symbol of Australia's Northern Territory
• Listed as protected species

Conservation Message

Important Note: When an eagle is killed, there are probably chicks in the nest that will die as well.

How to Help Eagles on Roads:

• Slow down when you see them feeding
• Hit the horn from when you first see them until you're past
• Gives them time to take off safely
• Move carcasses clear off the road into the bush

Cultural Significance

Aboriginal Dreamtime

Wedge-tailed Eagles feature prominently in Aboriginal culture:

Bunjil the Creator: For the Kulin people of central Victoria, the eagle Bunjil is an important creator being. Bunjil created the land, animals, and people.

Wilto (Southern Cross): For the Kaurna people of the Adelaide Plains, the eagle's claw takes the form of a constellation known as Wilto - the Southern Cross.

Spiritual Significance:

• Appears in many Dreaming stories
• Symbol of power and creation
• Connection to sky and spiritual realm
• Important cultural totem for many groups

Modern Australian Culture

• Official symbol of Australia's Northern Territory
• Featured on emblems and logos
• Symbol of Australian wilderness
• Subject of photography and art
• Educational icon
• Represents conservation challenges

Interesting Facts

1. Bold Indeed: The scientific name audax means "bold" - fitting for an eagle that attacks adult kangaroos and aircraft!

2. Massive Nests: Their 400 kg nests are among the largest bird nests in the world.

3. Vision Champion: Can see 8 times more detail than humans and spot prey from 2 km away.

4. Long Maturation: Takes 10 years to reach full adult black plumage!

5. Aircraft Attacks: Known to attack hang gliders, model planes, and even helicopters perceived as threats.

6. Gradual Darkening: Young eagles start brown and progressively darken over their first decade.

7. Commensal Landlords: Small birds nest in the underside of their massive nests!

8. Rabbit Impact: The introduction of rabbits transformed their diet and boosted populations.

9. Safety Goggles: Have a third transparent eyelid (nictitating membrane) for eye protection.

10. Group Hunters: Can coordinate to take down prey as large as adult kangaroos.

11. Long Lives: Can live up to 40 years in the wild.

12. Sibling Rivalry: Often only one chick survives as the largest kills and eats smaller siblings.

13. Persecution History: Over 300,000 eagles killed in just two states over 40 years.

14. Fourth Largest: Fourth largest eagle in the world!

15. Female Dominance: Females are up to 33% larger than males - significant size difference.

Observing Wedge-tailed Eagles

Best Times and Places

Where to Look:

• Open country and farmland
• Perched on tall trees or poles
• Soaring at great heights
• Along roadsides (unfortunately, often feeding on roadkill)
• Rocky outcrops and escarpments
• Near water sources

When to Observe:

• Early morning (hunting time)
• Late afternoon/sunset (hunting time)
• Clear days with thermal updrafts (soaring)
• Year-round (resident species)

Identification Tips

In Flight:

• Unmistakable wedge-shaped tail
• Long, broad wings with "fingered" tips
• Soars effortlessly at great heights
• Dark overall appearance
• Size - huge!

Perched:

• Very large dark bird
• Feathered legs to toes
• Long tail visible
• Often on highest perch available
• Upright posture

Safety and Etiquette

• Never approach nests (may cause abandonment)
• Observe from distance with binoculars/scope
• Don't disturb breeding pairs
• Report persecution to authorities
• Help protect roadside-feeding birds by slowing and honking

Similar Species

White-bellied Sea-Eagle

Australia's second-largest raptor:

• Shorter, more rounded wings
• Unfeathered lower legs (key difference!)
• White belly and underwings
• Different habitat (coastal, near water)
• 15% smaller, 25% lighter

Little Eagle

The only other Aquilinae eagle in Australia:

• Much smaller (45-55 cm)
• Different proportions
• Lighter build
• Different tail shape

Conclusion

The Wedge-tailed Eagle stands as an apex predator and an enduring symbol of wild Australia. From its commanding presence soaring thousands of meters above the landscape to its fierce defense of territory against even aircraft, this magnificent raptor embodies power, adaptability, and resilience.

Despite suffering catastrophic persecution that saw over 300,000 birds killed in just four decades, the Wedge-tailed Eaglehas survived to remain the most common of the world's large eagles. Its ability to thrive across diverse habitats - from alpine regions to arid plains, from remote wilderness to farmland - demonstrates the remarkable adaptability that has allowed it to persist.

Yet challenges remain. With a 28% national population decline, ongoing poisoning threats, and the endangered Tasmanian subspecies, the future of this iconic eagle is not guaranteed. Every time we slow down for an eagle feeding on the roadside, every time we protect nesting habitat, every time we correct misconceptions about lamb predation, we contribute to the conservation of this remarkable species.

Whether seen as Bunjil the creator in Aboriginal Dreamtime, the official symbol of the Northern Territory, or simply as a majestic silhouette soaring effortlessly against an endless blue sky, the Wedge-tailed Eagle continues to inspire awe and respect. This bold eagle deserves our protection, admiration, and commitment to ensuring its reign over Australian skies continues for generations to come.

The Wedge-tailed Eagle represents the untamed spirit of Australia - powerful, adaptable, and enduring - a living reminder that even the mightiest face challenges, but with protection and respect, can continue to soar.