Critter Of The Week #3 : Northern Gannet

 The Northern gannet is a large and beautiful seabird that spends most of its time in the open ocean of the North Atlantic. They travel as far south as the Caribbean and Gulf of Mexico too. They are most famous for their incredible torpedo-like high speed diving ability, and are able to swim underwater for up to a minute using both their wings and their duck-like webbed feet to search for fish. For a bird that also flies in the air, that's an impressive feat! 

 

These birds can dive from heights as high as 100 feet and reach speeds in excess of 62 mph. If a human did a pencil dive into the water at those speeds, they would perish from the force of the impact with the water's surface! The Northern gannet has several incredible adaptations that we will detail below which allow it to achieve such a death-defying feat thousands of times throughout its life. 

 

 

Adults have a wingspan up to 6 feet wide and weigh 8 pounds on average. Your average chicken is 5 pounds, so for a diving bird like this one to plunge as fast as they do, it is truly amazing they do not die on impact. 

 

They have very few predators and are doing quite well as a species. The only animals that occasionally hunt Northern gannets are sharks, seals, and some birds of prey such as bald eagles.  

Scientific Classification :

Kingdom : Animalia

Phylum : Chordata

Class : Aves

Order : Suliformes

Family : Sulidae

Genus: Morus

Conservation Status : 

Colugo Conservation Status
"Least concern" means their population has been counted, but they are not in imminent danger of extinction.

 

Number of Different Species : 1 

Northern gannet: Morus bassanus

 

Range :

Habitat :

Unless it is breeding season, Northern gannets spend most of their time in the open ocean feeding. When it comes time to reproduce, they congregate on rocky islands in colonies of up to 300,000 birds.

Diet & Hunting Technique :

These birds are spectacular high-speed divers. With this comes an array of amazing adaptations that make them the fastest and deepest diving birds on earth.

 

Forward facing eyes give them depth perception much like a primate or cat so they can accurately judge distances and spot fish underwater from up to 150 feet in the air. They do not have external nostrils and their ear openings are covered in feathers and can be closed while underwater. A strong sternum and a series of air sacs throughout their body act as shock absorbers on impact. The air sacs can also be filled with oxygenated air when the bird inhales. When they exhale, that air will then go into their lungs and provide them with an extra boost in endurance.

 

When they prepare to dive, they fold their feathers back and take on the shape of a spear. Their life depends on getting the form right; if they hit the water at the wrong angle, they could break their neck!  This series of images shows the whole process.

 

They are right at home underwater too. This is enabled by a unique waxy-like substance they apply to their feathers with their beak or head that makes their feathers completely waterproof. This gives them buoyancy in the water and makes it easy to fly away once they reach the surface. They can dive up to 50 feet underwater and hold their breath for 45 seconds.

When they do surface, as seen in the image below, the water literally beads off of their body and allows them to take off from the water without waiting to dry off. 

Northern Gannet by Jamie-MacArthur on DeviantArt

 

In the video below, you can see the entire process for yourself. 

Reproduction :

Northern gannets gather in incredible numbers to reproduce. The largest colony has almost 300,000 birds and is usually located on a rocky island or cliff sides so they can avoid predators.

 

Depending on where they are geographically, the breeding season starts around mid-January to March in other areas.

 

The oldest birds will arrive first and the males will locate a nest site and begin attracting a mate. Females will fly over the area to find the right suitor. Once they match up, they will stay together for several seasons or for life. Amazingly, once they have successfully reared their chick for the season, they will separate and come together the next year. That means out of 300,000 birds, they have to find their mate from the previous year.

 

Once a spot has been chosen, the pair will begin gathering nest material like seaweed and other natural debris.

 

Notice how the nests are neatly spaced from each other. This is because birds of the same gender will attack any neighbors that get too close.

 

 

Interestingly, females will only attack females if they come too close, if males come nearby, the females leave them alone.

 

 

When it's time, the couple lay just one egg. Gannets have the amazing ability to pump blood into their feet to warm the eggs when needed. In about 45 days, it will hatch. The adults will take turns going out to sea and gathering food to feed their chick for about 11 weeks. After 75 days, the chicks will shed their soft fluffy down feathers for darker plumage and will start venturing out to sea.

 

 

Once chicks are fully mature they will start developing the ivory white coloring of their parents.   

 

 

Relationship With Humans :

 

Historically, in the late 1800's, Northern gannets were heavily hunted for their meat. Their eggs were also stolen for food and the population was in rapid decline. 

Once protection measures were implemented, they rebounded and are currently doing quite well. Each year, their population is experiencing a 3-5% growth, which is rare for a large ocean-going bird. The global population is estimated between 950,000 - 1,200,000 birds. It is great to hear about an animal so unique doing so well.  

There is one area in the United Kingdom that allows an annual hunt of 2,000 birds to be used as a local delicacy.

Otherwise, Northern gannets live out their lives relatively undisturbed.