Arrows of the Sea

Over the unlucky school of fish is a bewildering maze of soaring, circling birds, pouring down out of the sky in rapid succession, plunging into the water like so many projectiles and sending columns of water and spray many feet into the air like the spouting of a school of whales.

~Arthur Cleveland Bent, 1922, describing a flock of northern gannets feeding on a school of herring

Last Saturday was one of those days when it all seems to come together. I had a chance to really observe a species that I have wanted to see up close for a long time. What made it all possible was a pelagic birding trip aboard the Stormy Petrel II out of Hatteras. One of my goals for the trip was to observe northern gannets (Morus bassanus) up close and personal. For decades, I have seen them flying and diving off the beach. Over 30 years ago, while working as the East District Naturalist for NC State Parks, I found one dead on Hammocks Beach. I remember being stunned by the beauty and size of the bird I had previously only seen through binoculars. I have since watched them plunge-diving by the hundreds from places like Bald Head Island, and seen some flying nearby while offshore on various boats. But here was a chance, from what I had heard, to spend several hours watching them close to a boat while trying to photograph their flight and dives. I was not disappointed!

Northern gannet at sunrise

Northern gannet at sunrise (click photos to enlarge)

It didn’t take long for a couple of northern gannets to start following our boat as we passed through the inlet just after sunrise. As always, I was struck by their graceful, strong flight, and their striking head colors.

Northern Gannet  with sky, ocean, and clouds

Northern gannets have a distinctive shape and can be identified at great distances

When you see a northern gannet adult from afar, you see a white cross with black wing tips. It is a distinctive shape – pointed at both ends with long, narrow wings. The Peterson Guide to Seawatching pointed out something that surprised me – northern gannets have a wingspan slightly shorter than that of a brown pelican, but longer than a tundra swan! That makes them the largest bird, other than a pelican, you are likely to see off our coast.

Immature northern gannet

Immatures are varying shades of dark brown with lighter splotches and speckling

Of the hundreds of gannets seen, we only had two sightings of the darker-colored immature birds during the trip. Once they leave the nest, these young gannets are believed to stay at sea for at least 3 years before returning to land.

Pair of northern gannets

Almost all of the northern gannets off our coast in winter are adult males

One interesting factoid that came up was that field studies the past couple of decades (largely by the late Dave Lee at the NC Museum of Natural Sciences, as reported in his book, Gulf Stream Chronicles) have revealed that almost all of the northern gannets wintering off the Carolina coast are adult males. This was determined by collecting and examining specimens, since the adult plumage of both sexes is basically identical. This has huge implications for conservation and management of this species. Since northern gannets off the Outer Banks in winter can number in the thousands, any ecological disaster in the area, such as an oil spill, could impact a disproportionately large percentage of the breeding population of this species. This is especially true since this species takes 4 to 6 years before reaching breeding age, and they typically lay only one egg per year.

Northern Gannet head close up

You can only appreciate the blues on their face when you see one up close

One of the great highlights of the trip for me was being able to observe the gannets up close. It is only then that you can clearly see and appreciate the subtle colors of the adult bird’s head. The piercing eyes are lined with a light blue. The large, pointed bill is a blueish-gray color with black lines that outline it, the eye, and extend beyond the gape of the bill onto the neck. The head is tinged in a buff or gold color that varies among individual birds. Gannets have no external nostrils. Close inspection shows a slit-like opening near the base of the bill covered by a flap, which is forced shut over the opening when the bird plunges into the water.

binocular vision

Eye placement presumably gives them binocular vision

The eyes look forward, presumably giving them good binocular vision, an important aid in accurately determining distances when diving after their prey.

Northern gannet at sunrise with bill open

Gannet croaking as it flies behind the boat at sunrise

Although believed to be generally silent at sea, many of the birds coming into the chum gave a grating, guttural croak as they maneuvered for position among the other birds.

Gannet fight over fish

Two gannets with heads underwater attract a curious pelican

Most of the gannets we observed were diving after the chum being tossed off the stern of the boat, but we did witness them feeding on something different at one point. We passed by two gannets huddled together, heads underwater. They were soon joined by a pelican, who soon stuck his beak into the action.

Gannet fight over fish with pelican joining in

The pelican joins the fray

I couldn’t quite tell what was going on until one gannet gave up, and the other emerged victorious.

Gannet fight over fish 1

One gannet pulls away with the prize

It turned out one of the gannets had caught a houndfish, a long, skinny member of the needlefish family.

Northern Gannet with fish

Going…

Northern Gannet with fish 1

going…

Northern Gannet swallowing fish

gone!

The bird finally won the struggle with its writhing prey and gulped it down.

Northern Gannet dive 14

Northern gannet plunge-diving

To catch their prey, northern gannets perform extraordinary plunge-dives from heights of as much as 100 feet above the ocean. From the shore, I have seen large flocks pelleting the ocean surface after fish in what one person has described as birds machine-gunning into the sea. These birds have special air sacs just under their skin, which one reference likened to bubble wrap under their feathers. This supposedly helps cushion the impact of the striking dives.

Northern Gannet with sky and clouds 2

Cruising, scanning the water below for prey

Northern Gannet turning toward water

If something is spotted, sharp turns or other maneuvers, using the tail and wings, may be necessary

Northern Gannet looking to dive 1

Zeroing in on the target at speeds that can approach 54 miles per hour

Northern Gannet looking to dive 2

Wings folded back against body as the bird hits the water like a feathered spear thrown by the clouds

The anatomy of a typical low altitude dive is presented in the 4 photos above.

I mentioned in my last post that I took more photos on this trip than I ever have in any one day. Part of the reason is the fast frame rate of my camera (10 frames per second) coupled with my desire to capture a sequence of images of a northern gannet plunge dive. So, I took hundreds of images of these birds torpedoing into the water around the boat. Here are just a few more…

Northern Gannet at moment of imact

Northern Gannet dive 4Northern Gannet looking to dive 2bNorthern Gannet dive 11Northern Gannet vertical diveNorthern Gannet just at impact with oceanI think my favorite is this last one, just before the moment of impact. I observed that many of the divers entered the water at a slight angle, rather than straight down, probably due to the low altitude from which they were spotting the chum, and the abundance of other birds in the air directly above the food. Northern gannets usually dive to relatively shallow depths (10 feet), but can, if needed, dive much deeper (75 feet or so).

Northern Gannet landing on water

Gannet landing on the ocean surface

When not plunging down like arrows shot into the water, the gannets often employed another type of shallow dive. They hover just above the water surface, touch down, and then stick their head and neck underwater.

Northern Gannet landing on water 1

Gannet doing a shallow dive while landing on the water

Maybe they can’t help themselves and they just have to at least take a look underwater when they land on it.

Northern Gannet sitting on water

The gannets took turns diving, then briefly resting on the surface

Northern Gannet swallowing lifting off water

Their lift-off is rather clumsy

As the afternoon continued, the gannets began to alternate between bouts of diving and brief spells of landing on the water. This is how they also often behave during migrations, slowly making their way from the breeding grounds in the far north to feeding areas along the east coast. Now that I have spent a day with the divers, I really want to travel north to see their breeding colonies. There are an estimated 60,000 breeding pairs on Bonaventure Island in Canada, one of the six main breeding sites for North Atlantic northern gannets. What a sight that must be! Until then, I will seek out time with these amazing arrows of the sea anytime I can get it.

Northern Gannet turning to dive 1

An extraordinary bird, indeed.

 

 

 

Pelagic Birding

You may know the true observer, not by the big things he sees, but by the little things; and then not by the things he sees with effort and premeditation, but by his effortless, unpremeditated seeing—the quick, spontaneous action of his mind in the presence of natural objects.

John Burroughs, 1905

I had the good fortune to do something this past weekend that I have never done – go on a pelagic birding trip off the coast of North Carolina. I went with a group organized by the North Carolina Museum of Natural Sciences that included some museum staff, educators, and some members of the public interested in birds. The trip was aboard the Stormy Petrel II, a 61 foot charter boat run by Brian Patteson of Seabirding. Though I have been to sea several times on a variety of vessels, this is the first time I have gone off the Outer Banks, and the first time with the primary purpose of seeing birds and other marine life.

Sunrise

A beautiful sunrise to start the day (click photos to enlarge)

The day started early with a gorgeous sunrise, which is a good sign if you are heading offshore in winter. It was cold, and I had put on everything I brought with me, just in case.

Cormorant flock leaving the roost

Large numbers of double-crested cormorants were starting their day as we headed out

Birds made their presence known even before we left the dock with a sharp-shinned hawk gliding over us as we listened to our orientation for the charter. I was reminded of the incredible abundance of life on our coast as huge numbers (many thousands) of double-crested cormorants began leaving their evening roosts as we departed the dock.

Brown pelican adult

Adult brown pelican in early morning light

A beautiful golden light flooded the scene when the sun cleared the low clouds, making everything glow. Brown pelicans were among the first birds to accompany us as we headed through Hatteras Inlet.

Kate

First mate, and birder extraordinaire, Kate, throwing out some chum behind the boat

It didn’t take long to realize that the excellent reputation I had heard for the birding (and other) knowledge of Brian and his crew are well deserved. Brian and his first mate, Kate, both have extensive knowledge of the area and its abundant wildlife. They quickly picked out rarities among the hundreds of birds surrounding us and could do so at incredible distances (on a boat that was rocking fairly significantly at times). The John Burroughs quote above is for the museum staff, and some of the birders aboard, but especially for Brian and Kate. It is always a joy to be out in the field with people that are both knowledgeable about the area, and passionate about what they do.

Birds following the boat

Birds following the boat

As we got offshore and began to throw chum off the stern, the bird assemblage grew in numbers and diversity. At first it was mainly several species of common gulls, some pelicans, and northern gannets, then some rarities, that are seldom seen from shore, started to accompany us.

glaucous gull 1

Glaucous gull is a new species for me

One of the first was a new species for me, an incredibly beautiful glaucous gull. This large white gull is an immature bird with some faint mottling and a black-tipped bill.

 

northern fulmar 1

Northern fulmar rocketing by the boat on outstretched wings

Next was a species I had seen a decade ago when I was lucky enough to spend time in the Arctic aboard a Russian icebreaker on a climate research and education mission. Northern fulmars are somewhat gull-like in appearance. They have thicker necks and can be recognized at great distances because of their flight pattern – rapid, stiff wing beats, or long periods of soaring, often in an undulating pattern above the waves, with stiff wings, and often turning with wings held perpendicular to the ocean. They are fast, efficient fliers, built for taking advantage of the uplift from ocean waves. They can be variable in color, but we mainly observed the lighter color form.

northern fulmar 3

Fulmars are one of the tubenoses, recognized by a hollow ridge on top of their bill

Fulmars belong to a group known as tubenoses along with albatrosses, petrels, and storm-petrels. These pelagic species must drink sea water, and therefore are adapted to rid themselves of excess salt via active salt glands. The tubular structures on top of the bill are thought to help direct the excretions from the salt glands away from the eyes. The tubes also play a role in the well-developed sense of smell that these birds use to find food in their vast ocean habitat. A keen olfactory sense is rare among birds, but tubenoses use both sight and smell to locate food. They are known to fly back and forth into the wind tracing the source of a food smell.

northern fulmar 2

Northern fulmars are a long-lived species

Many pelagic species are long-lived and take years to reach breeding age. Northern fulmars may be one of the champions in this regard. They generally do not breed until they are 8-10 years old, and may live 40 or more years. One reason they may live so long is that both chicks and adults have what seems like a very effective deterrent to predators – they can eject a foul-smelling stomach oil up to several feet. This can be particularly effective against avian predators as the oil can mat the feathers together, causing the death of the predatory birds.

the change

At “the change”, where warm waters (bottom) meet colder waters

Not far offshore we reached what the captain called, “the change”, a zone where two water bodies of different temperatures converge. It was immediately noticeable by a distinct line between water of two colors – a brownish tint to the colder inshore waters of about 50+ degrees F, and the clear, blueish-green waters with temperatures around 70 degrees F. This zone creates a concentration of sea life and sea birds.

razorbill flock

A flock of razorbills

In addition to the fulmars, we started seeing scattered small flocks of razorbills streaking just above the waves. Razorbills are in the group known as alcids that also includes Atlantic species such as puffins, murres, and dovekies. This group, also known as the auks, all have short, somewhat stiff wings that they use in pursuit diving for their oceanic prey of small fish and marine invertebrates. They tend to fly low over the water with rapid wing beats.

Atlantic puffin taking off

An Atlantic puffin

We did see a few Atlantic puffins, although most at a bit of a distance. A few kept leaping out of the water, flying low for a short distance, and then plunging back into the waves. The abundance of gulls, especially larger predatory species such as great black-backed gulls, was apparently enough to make these small birds very nervous about being exposed on the surface.

black-capped petrel 1

Black-capped petrel

At one point a shout went out from the bridge – “black-capped petrel off starboard”. This is a species not often seen this close to shore, so it was a great find on our cruise.

sooty shearwater

Sooty shearwater

We also saw a couple of shearwaters, another type of tubenose. A manx shearwater made a quick pass and a sooty shearwater stayed with us for several minutes, joining the feeding flock behind the boat. They exhibit what is called dynamic soaring, alternating between arcing above the water and dipping and soaring just above the wave tops (“shearing” off the top of the water).

loggerhead sea turtle

One of several loggerhead sea turtles we saw

The abundance of life in this zone included many species other than birds. We saw several sharks, including a couple of very large hammerheads, plus a number of sea turtles.

mola mola

Ocean sunfish fin sticking out of the water

A highlight for many was the appearance of a huge ocean sunfish, Mola mola. These bizarre-looking fish are the largest of bony fishes in the sea, reaching up to ten feet in length and 5000 pounds.

spotted dolphin underwater next to bow

Atlantic spotted dolphin next to the boat

spotted dolphin leaping back into water

The dolphins enjoyed riding the bow wave

While cruising back and forth within sight of the Diamond Shoals Light, we were entertained by a pod of Atlantic spotted dolphins, Stenella frontalis. These beautiful creatures of the Gulf Stream frolicked next to the boat for many minutes, riding the bow wave and occasionally leaping out of the water to the excited shouts of everyone (even those that were experiencing the scourge of rough waters, seasickness).

Pelican guest

Look who is coming aboard!

We also had a close encounter of the pouched kind…a juvenile brown pelican landed on the top deck of the boat and sat up there for quite some time before flopping down on the head of someone trying to recover from her queasiness on the rocking boat.

Pelican guest 1

This pelican hitched  ride with us for a couple of hours

Kate helped the bird off the boat not once, but twice before it got the message that this cruise was for paying passengers only. It was an incredible adventure for everyone. The museum staff had prepared everyone well for the journey with information on hat to bring and how to best avoid seasickness. They also had given great information on some of the species we might expect to see. I ended up taking more photographs than I ever have in one day, many taken while trying to capture the amazing dives of the elegant northern gannets that accompanied us all day (more on that in the next post). For more information on the trip, including a species list, you can visit Brian’s blog. For a good overview of the importance of this area to marine life, I highly recommend the book, Gulf Stream Chronicles, by the late Dave Lee, an ornithologist at the NC Museum of Natural Sciences. Dave worked for years helping to document the bird life and other marine species found off the Outer Banks and helping reveal how rich this ecosystem is in ocean life. Below are just a few more images from an amazing day in the critically important waters off our coast.

Juvenile brown pelican landing in water

Juvenile brown pelican landing behind boat

brown pelican adult at sunrise

Brown pelican in the golden glow of sunrise

common loon

Common loon

spotted dolphin wave riding

A dolphin surfaces next to the boat

glaucous gull 2

This glaucous gull followed us most of the day

northern fulmar

Northern fulmar riding the wind above the waves

Black-legged kittiwake

Black-legged kittiwake

Mass of birds behind the boat

Mass of birds feeding on chum behind the boat

northern gannet

Northern gannet (more on this species in my next post)