The great cormorant (Phalacrocorax carbo) is a large waterbird in the cormorant family Phalacrocoracidae. It is commonly found across parts of Europe, Asia, Africa, Australasia and the Americas. Great cormorants are skilled swimmers and divers, using their feet to propel themselves underwater in search of fish and other prey. But despite spending so much time in the water, great cormorants are also capable of flight. So the answer is yes, great cormorants can fly.
Anatomy and physiology of great cormorant flight
Great cormorants have a number of anatomical and physiological adaptations that enable them to fly:
- Lightweight, streamlined body – Their bones are hollow and their body is slender and smooth to reduce drag.
- Large wingspan – Their wingspan reaches up to 1.3 meters, providing a large surface area for lift.
- Powerful flight muscles – Their breast muscles are very strong to enable powerful wingbeats.
- Keel on breastbone – The keel provides an anchor for the large flight muscles to attach to.
- Webbed feet fold away – Their webbed feet can fold back cleanly against the body during flight to reduce drag.
These adaptations allow great cormorants to get sufficient lift and thrust to become airborne and propel themselves through the air despite their large size. The muscles and cardiovascular system supply the energy needed for flight. So their anatomy and physiology is specialized for both swimming and flight.
Great cormorant flight behavior
Great cormorants exhibit a range of flight behaviors and capacities:
- Powerful takeoff – They use a burst of rapid wingbeats and their feet to launch themselves into the air from the water’s surface.
- Flap gliding – Their flight consists of flapping phases interspersed with short glides.
- Swift and direct – They fly fast and straight towards their destination.
- Migratory flight – Some populations make long migratory journeys of thousands of miles.
- Height – They typically fly at heights of around 100 feet but can fly much higher.
- No soaring – They flap continuously rather than soaring like some birds.
- Agile maneuvering – They can adeptly bank or change direction.
So great cormorants are strong, capable fliers. They use their flight abilities to travel between nesting, roosting and feeding sites. It allows them to cover large distances efficiently during migration or everyday commuting. Overall, their flight performance matches their lifestyle.
Differences in flight ability
There are some differences in flight capabilities and behavior between populations and subspecies of great cormorants:
- Longer migrations – Northern breeding birds migrate further so may be more efficient fliers.
- Heavier birds – Larger subspecies are heavier which could reduce flight performance.
- Feeding flights – Coastal birds make more short fishing flights than inland birds.
- Experience – Juveniles and fledglings have less developed flight skills.
- Molt – Flight ability is temporarily reduced during the annual wing molt.
But in general, all great cormorants are accomplished fliers because flight is essential for their way of life. The differences merely reflect adaptations to local conditions and roles.
Comparison to related cormorants
The flight ability of great cormorants is broadly similar to that of other cormorant species. Features shared across cormorants that enable flight include their streamlined body shape, large wingspan, stiff tail feathers and sharply hooked bill.
Some differences compared to other cormorants:
- Bigger – Great cormorants are one of the largest cormorants so require more power.
- No crests – Some cormorants have head crests which may increase drag.
- Shorter wings – Some species have even longer, narrower wings.
- Pelagic skill – Some cormorants forage far out at sea and so may be more maneuverable.
But essentially, all cormorant species exhibit similar strong flight capabilities. This allows them to thrive around waters across diverse habitats worldwide.
Flight speeds
Some research studies have measured the flight speeds of great cormorants:
- Cruising speed – Typically 24-35 mph (38-56 km/h).
- Max speed – Can reach around 45 mph (72 km/h) in level flight.
- Speed in flapping phases – Average of 21 mph (34 km/h).
- Speed in gliding phases – Average of 28 mph (45 km/h).
Their airspeed is a bit slower than fast-flying ducks or geese. But great cormorants are not built for rapid flight. More important is minimizing energy use while carrying the load of their large body size. So they spend a lot of time gliding to save energy between flapping bouts. Their flight abilities match their ecological niche well.
Factors influencing flight speed
Factors that can influence the flight speed of great cormorants include:
- Wind – They fly faster with tailwinds and slower into headwinds.
- Flight purpose – Faster when commuting, slower when foraging.
- Load – Carrying heavy fish loads reduces speed.
- Time of year – Slower during molting as new feathers grow in.
- Time of day – May fly slower at dawn or dusk.
- Weather – Rain or strong heat can decrease speed.
- Health – Illness or injury can impair flight ability.
By modulating their airspeed and effort, great cormorants can fly efficiently and safely under diverse conditions. This flexibility enhances their flying ability.
Role of flight in great cormorant ecology
The flight capacity of great cormorants is vital to their ecology and lifestyle:
- Foraging – Allows them to commute to fishing areas up to 20 miles away.
- Migration – Enables long seasonal migrations to utilize distant resources.
- Breeding – Necessary to gather nesting materials and feed young.
- Roosting – Commute between day roosts and night roosts daily.
- Dispersal – Young birds use flight to disperse to new sites.
- Avoid threats – Take flight to escape terrestrial predators.
Great cormorants occupy an ecological niche as a waterbird that relies on both swimming and flight. This sets them apart from flightless waterbirds like penguins. It also distinguishes them from weak-flying divers like loons. Their strong flight abilities are integral to their ecology.
Consequences of flightlessness
If great cormorants could not fly, the consequences would likely include:
- Restricted foraging range – Unable to reach distant or offshore feeding areas.
- No migration – Obligate year-round residents unable to escape harsh conditions.
- Constrained dispersal – Less gene flow and ability to colonize new sites.
- Greater threats – More vulnerable to predators and human activity on land and water.
- Competition – Outcompeted by other birds in some habitats.
- Population declines – Reduced fitness and survival would cause declines.
So flight is closely tied to the behavioral ecology, distribution, abundance and resilience of great cormorants. Losing flight would clearly have major detrimental impacts.
Threats to great cormorant flight ability
Some threats can negatively impact the flight ability of great cormorants:
- Power lines – Collision can cause injury.
- Human disturbance – Flush flight burns more energy.
- Pollution – Can reduce feather waterproofing.
- Oil spills – Can mat feathers needed for flight.
- Fishing tackle – Entanglement can restrict wing movement.
- Habitat loss – Removes roosting and nesting sites.
- Culling – Population control shoots birds.
- Climate change – Could disrupt habitats and migration timing.
Conservation measures to counteract these threats and preserve flight ability are important for protecting great cormorant populations.
Conservation status and protection
The global conservation status and legal protections for great cormorants include:
- IUCN Red List – Classified as Least Concern currently.
- CITES – Not listed, so no limits on international trade.
- Protected in Europe under EU Birds Directive.
- Legally hunted for sport and culled in some countries to limit impact on fisheries.
- Sustainably hunted for food by indigenous groups in some regions.
Overall great cormorants remain widespread and common globally. But some populations and subspecies are declining or threatened. Continued monitoring and protection of habitats and movement corridors will help maintain robust populations of these iconic waterbirds into the future.
Conclusion
In summary, great cormorants are highly capable fliers thanks to their anatomy and physiology adapted for both swimming and flight. Their strong flight abilities are integral to their behavioral ecology and resilience. While not the fastest fliers, they can migrate long distances and cover extensive daily ranges to forage and roost as needed. Some threats can impact flight ability, so conservation efforts are important. But as long as suitable wetland habitats remain, great cormorants will continue using their amazing flying skills to exploit aquatic resources across the Northern Hemisphere. The answer is definitively yes – great cormorants can fly and do so with grace and speed fitting their role.
