The Northern Gannet (Morus bassanus) is a large seabird that lives in the North Atlantic Ocean and is known for its striking white plumage and long pointed beak. Gannets are the largest seabirds in the North Atlantic and have a wingspan of up to 6 feet across. These birds are skilled divers that plunge into the ocean at high speeds in search of fish, squid, and crustaceans to eat. Northern Gannets have a life expectancy of around 20-30 years in the wild.
Range and Habitat
Northern Gannets are found across the North Atlantic Ocean along the coasts of Canada, Greenland, Iceland, Northern Europe, and down to the Carolinas on the East Coast of the United States. Their breeding range centers around islands and remote cliffs across the North Atlantic. Some of the major nesting sites are in the Gulf of St. Lawrence in Canada, around Iceland, Northern Scotland, Ireland, and the Faroe Islands. Northern Gannets spend most of their life out at sea, only coming to land to breed and nest. They can be found wintering further south along the North American coast down to Florida and along the coast of Western Europe.
Diet
Northern Gannets feed exclusively on fish and marine invertebrates. They hunt by diving from heights of up to 130 feet, plunging into the ocean at speeds of over 60 mph. Their streamlined bodies and pointed beaks help them pierce the water to grab prey. Some of their common prey items include herring, mackerel, cod, squid, and crustaceans like crab and lobster. Northern Gannets can dive to depths of over 100 feet beneath the surface. Their air sacs under their skin help cushion the impact when they hit the water. Northern Gannets are able to store extra air in their throat and chest cavity to stay underwater for longer periods hunting for food.
Breeding and Nesting
Northern Gannets nest in large colonies that can number in the tens or hundreds of thousands of pairs. Their nests are simply a mound of seaweed, feathers, and droppings piled together on cliff ledges or isolated islands. Northern Gannets are monogamous and mate for life. They reach sexual maturity between 4-6 years old. The breeding season takes place between April and September. Females lay one blue egg that both parents will take turns incubating over 42-46 days. The egg hatches in May or June revealing a white downy chick. For the first 2-3 weeks the chick is brooded and fed regurgitated fish by the parents. After this, the parents leave the chick alone on the nest site while they go out fishing. The chick will fledge at around 12 weeks old and take its first flights from the nest. The young gannet is dependent on its parents for an additional 6-12 weeks as it learns to fish and fly competently on its own.
Migration
Northern Gannets residing in the northern parts of their range, like Canada and Iceland, will migrate south for the winter months. They spend winter along the Atlantic coast of the U.S and western Europe. Northern gannets can travel immense distances during these seasonal movements. One banded gannet was recorded traveling over 3000 miles between its breeding site in Canada to its winter grounds off the coast of Texas. Their migrations are largely influenced by the seasonal availability of prey fish like herring, mackerel, and cod. Some younger gannets may not migrate and remain closer to their natal nesting grounds year-round until they reach breeding maturity.
Lifespan in the Wild
The average lifespan of wild Northern Gannets is 20-30 years. The maximum recorded lifespan for the species is 35 years according to bird banding records. Their lifespan is on the longer side for a seabird species. Gannets don’t face any regular natural predators besides some large gulls who may occasionally prey on eggs or young chicks. However, they do face threats from human activity. Getting tangled in fishing gear, ingesting plastics, oil spills, and disturbance of nesting colonies all pose risks. Conservation efforts across their range aim to preserve and protect Northern Gannet populations and their breeding habitats.
Appearance and Characteristics
Northern Gannets are large sleek seabirds with long narrow pointed beaks and bright white plumage with black wingtips. Here are some key identifying characteristics and features:
- Length: 35-43 in
- Wingspan: 5.9-6.9 ft
- Weight: 5-8 lbs
- Adults have all white plumage with black wingtips
- Pointed gray bill with yellow hue
- Blue-gray eyes ringed with pale blue skin
- Juveniles are dark brown gradually getting whiter
- Webbed feet are black with a yellowish hue
Northern Gannets are the largest white seabird found in the North Atlantic. Their size, distinctive plumage, and body shape make them easy to identify. They may be confused with other white seabirds at times like jaegers or boobies that share parts of their range.
Development and Growth
Northern Gannet chicks hatch from their blue-colored egg after an incubation period of 42-46 days by the parents. The hatchling is covered in white down and relies completely on its parents for warmth, protection, and food. At two to three weeks old, the chick is left alone on the nest site while both parents leave to hunt for fish. It becomes more alert and active, stretching its wings in preparation for fledging. After about 12 weeks the juvenile will take its first flight from the nest to the sea. It is still dependent on its parents until it becomes efficient at flying, diving, swimming, and hunting over the next several months. Juveniles reach adult plumage after about 4-5 years old. Northern Gannets are ready to begin breeding around 5-6 years old once sexually mature.
Unique Adaptations
Northern Gannets have evolved several unique adaptations to their life spent diving into the ocean after fish:
- Air sacs – Nests under their skin act like bubble wrap to cushion impact with water.
- Nostril flaps – Valve-like flaps seal off nostrils when underwater.
- Vision – Special refractive shapes lenses and corneas help them focus underwater.
- Body shape – Sleek, torpedo-shaped for plunge diving.
- Feet – No hind toe, and webbed for powerful swimming.
These adaptations all help the Northern Gannet excel under the water when hunting for fish. Their unique fishing method of plunge diving from the air to the depths has led to these specialized features.
Relationship With Humans
Northern Gannets have a mixed relationship with humans throughout their range. On one hand, they are respected and celebrated for their beauty, fishing skill, and curious nesting habits on precarious cliffs and islands. Watching them dive for fish is a sight that draws wildlife tourists. However, Gannets are also vulnerable to human activities. Vital nesting sites need protection, oil spills are a major hazard, and they get entangled by discarded fishing gear. Conservation efforts across their range aim to ensure Northern Gannet populations remain stable through habitation protection and reducing marine pollution.
Threats and Predators
Northern Gannets face a variety of threats to their survival in the wild including:
- Oil spills – Oil destroys their waterproof plumage leading to hypothermia and drowning.
- Plastic ingestion – Can choke or accumulate toxins in the body.
- Fishing nets – Birds can become entangled causing injury or drowning.
- Habitat loss – Human disturbance at nesting colonies.
- Reduced prey fish stocks – Overfishing effects food supply.
In terms of natural predators, only large gulls may occasionally eat eggs or young chicks. But overall, Northern Gannets do not face heavy predation pressure, especially adults. Their large size and nesting on isolated cliffs and islands reduces encounters with land-based predators. Their primary threats arise from human activities.
Population and Conservation Status
Currently, the global population of Northern Gannets is estimated at around 700,000 breeding pairs. Their numbers today are increasing and most colonies across the North Atlantic, like in Canada, are thriving. However, some southern populations, like in the Gulf of Saint Lawrence, have declined since the 1970s. Northern Gannets as a species are classified as Least Concern by the IUCN Red List due to their large range and stable overall population. Local conservation efforts are underway in parts of their range to protect vital nesting habitats and reduce marine pollution.
Key Facts and Summary
Here are some key facts to summarize Northern Gannet lifespan and biology:
- Range: North Atlantic Ocean, nest on cliffs and islands.
- Life expectancy: 20-30 years in the wild.
- Diet: Fish and marine invertebrates.
- Breeding: Nest colonially, mate for life.
- Threats: Marine pollution, habitat disturbance.
- Status: Least Concern.
- Unique features: Plunge diving specialists with adapted anatomy.
In summary, the Northern Gannet is a fascinating marine bird adapted to life in the North Atlantic. Thanks to a lack of natural predators and remote nesting sites, they can live 20-30 years on average. Conservation efforts ensure populations remain stable in the face of modern marine threats.
Conclusion
The Northern Gannet is a large and graceful seabird that thrives in colonies across the North Atlantic Ocean. Living up to 20-30 years on average, they are long-lived compared to many other seabird species. Their diving prowess, striking appearance, and remote island nesting habitats have ensured their success over time. However, modern marine hazards do pose risks requiring ongoing conservation actions across their range. Protecting the Northern Gannet’s nesting sites and reducing pollution will help ensure these iconic white-washed diving seabirds continue to thrive for generations to come.
