Fork-tailed Storm-Petrels and other Merbok castaways

The remnants of typhoon Merbok wreaked havoc in the Norton Sound region. Even the lives of seabirds, accustomed to ocean turmoil, were disrupted as they found themselves swept to places they surely never intended to go.

Many will remember the surprising appearance of hundreds of hungry bramblings last May when another powerful storm in the North Pacific intercepted their spring migration and dropped them on our shores.

While I am not aware of bird displacement on the scale of the brambling strandings, several unexpected seabird species were blown into Norton Sound during the recent storm. These rarities included two species of storm-petrels and a red-legged kittiwake.

Storm-petrels are tiny, tube-nosed seabirds. They look so delicate, yet they are masters of flight in strong winds, flying low and zigzagging between the waves in stormy seas. When feeding they hover over the water like little fairies, tiptoeing lightly on the surface to hold their place in the waves. They appear to be walking on water, which inspired the name “petrel” in reference to Saint Peter who was said to walk on water.

The tube-like structures on a storm-petrel’s bill filter and excrete salt, enabling the bird to drink water from the sea.

Fork-tailed Storm-Petrel

The fork-tailed storm-petrel is a common breeder in the Aleutians and North Pacific. They regularly forage in the southern Bering Sea and very rarely are seen as far north as St. Lawrence Island. Prior to the recent storm there were few records of them in Norton Sound.

During the storm small numbers of these dainty, silvery-grey seabirds were reported around the region on eBird––a worldwide, on-line record of bird observations. A flock of 58 fork-tailed storm-petrels was reported offshore of the Brevig Mission dump, two were reported in Unalakleet and six in Nome.

These birds normally come to land only to nest and likely don’t fly inland by choice. However, during the storm at least four fork-tailed storm-petrels were reported on the Kuskokwim River at Bethel––40 miles inland from the Bering Sea. In Nome, local birder Nick Hajdukovich was surprised to see a fork-tail storm petrel flying several miles inland over Anvil Mountain Correctional Center.

Fork-tailed storm-petrels nest in burrows or crevices on remote islands in the north Pacific and Aleutian chain. The female lays only one egg that is 20 percent of her body weight––one of the heaviest eggs in proportion to body weight in the bird world.

The chick is fed only at night by both parents, who usually bring it small fish.

They have an unusual adaptation for life at sea, where food can be distant and unpredictable and foraging difficult in stormy weather. During times of scarcity, the parents stop feeding the chick and remain at sea. The chick’s body temperature drops, it goes into a state of torpor and growth stops. When conditions improve, a parent returns to brood the chick. The chick’s temperature then rises, and growth continues when it is fed again.

Fork-tailed storm-petrels often forage in small flocks and rest on the surface of the sea.

When feeding they hover over the water and dip their bill to pick tiny crustaceans and small fish from near the surface. They can make shallow dives, but seldom do.

These birds have an extraordinary sense of smell and can detect food sources from miles away. Often they are the first birds to arrive at a floating carcass or fishing operation with an oily discharge. There they gather to skim floating oil off the water’s surface. They store the oil in a special stomach compartment to feed chicks. Or they may regurgitate the oily slurry onto a predator or neighbor when competing for a nest site.

If you didn’t see these birds during the storm, you probably missed your chance. They only lingered as long as the southwest winds pummeled the region.

Leach’s Storm-Petrel

In Nome, Nick Hajdukovich and visiting birder Steve Backus independently spotted an even more unusual storm-petrel for the region––a Leach’s storm-petrel. Their sightings were the first documented reports on eBird for Norton Sound. This species breeds in the Aleutians and forages over deep ocean waters, rarely as far north as the Bering Sea shelf.

Red-legged Kittiwake

Hajdukovich and Backus also independently spotted the first redlegged kittiwake to be recorded on eBird in Norton Sound.

Red-legged kittiwakes are known to nest only in the Pribilof, Aleutian and Commander Islands and probably on St. Matthew Island. They have seldom been documented as far north as St. Lawrence Island.

When Hajdukovich realized the storm track was coming directly through the Pribilofs, he recognized the possibility of finding a vagrant red-legged kittiwake amidst the commonly occurring black-legged kittiwakes at Nome’s port.

Hajdukovich ventured out in the storm to examine the port from a safe vantage point. For 40 minutes, using a spotting scope from his truck, he patiently scanned the 150 distant black-legged kittiwakes roosting on the east jetty and feeding in the waves between the jetties. Score! Eventually, a roosting bird shifted to reveal striking red legs that stood out even in a grainy photo taken in the dim, gray light of the storm.

Photo by Steve Backus RED-LEGGED KITTIWAKE– As the storm surge started to recede, birder Steve Backus checked the Nome harbor for birds pushed in by the storm. The wind was gusting to well over 40 knots and swells were still breaking over the seawall. After watching fork-tailed storm-petrels getting tossed about, he turned around and was surprised to see a redlegged kittiwake resting on the rock jetty about thirty feet behind him. Not wanting to bother this storm-tossed bird, he snapped a few photos and left.

Photo by Nick Hajdukovich LEACH’S STORM-PETREL– Nick Hajdukovich spotted this rare storm-petrel feeding alone in the rough water between the jetties at the Nome Port. Earlier in the day Steve Backus reported a Leach’s stormpetrel a mile east along the coast. These sightings are the first eBird reports of this species for Norton Sound. The dark brown color and white rump patch distinguished it from fork-tailed storm-petrels that were also blown in by the storm.

Photo by Kate Persons FORK-TAILED STORM-PETREL– Several of these rare visitors took refuge from Merbok’s fury in Nome’s harbor. As the storm was subsiding, the dainty bird fed in typical storm-petrel fashion, hovering over the water into the wind while steadying itself by dancing lightly on the water’s surface. You can see the tube-like structures on its bill that filter salt from seawater, enabling it to drink from the ocean.