Scopoli's Shearwater

About

Scopoli's Shearwater, often referred to as 'Zovoj' in some regional contexts, is a large pelagic seabird belonging to the order Procellariiformes, known for its long-distance migrations and characteristic gliding flight over open oceans. It is a prominent species in the Mediterranean and Atlantic, recognized by its dark upperparts and white underparts.

Size & lifespan

Length

45-56 cm

Wingspan

112-126 cm

Weight

500-1000 g

Lifespan

Up to 30 years in the wild

Diet

Carnivore (primarily fish and cephalopods)

Physical characteristics

Plumage

Adults have dark grey-brown upperparts, including the crown, nape, back, and upperwings. The underparts are pure white, contrasting sharply with the dark upperparts. The underwing is mostly white with a dark trailing edge and a dark patch at the carpal joint. The tail is dark.

Beak shape

Large, stout, yellowish-horn colored bill with a dark tip and prominent tubular nostrils on top. The bill is hooked at the tip.

Eye color

Dark brown.

Leg color

Pinkish-flesh colored legs and feet.

Distinguishing features

Large size, pale bill with dark tip, dark upperparts contrasting with white underparts, and a distinctive underwing pattern (white with dark trailing edge and carpal patch). Its flight is characterized by long, stiff-winged glides.

Juvenile appearance

Juveniles resemble adults but may have slightly fresher plumage and a less worn appearance. There are no significant differences in coloration or pattern.

Seasonal changes

No significant seasonal changes in plumage. Plumage remains consistent throughout the year.

Sexual dimorphism

Males and females are monomorphic in plumage and size, with no discernible external differences.

How to identify

1. 1

   Size and Shape

   Large shearwater with long, narrow wings held stiffly in flight. Appears robust.

2. 2

   Plumage Pattern

   Dark grey-brown upperparts (back, wings, head) contrasting sharply with pure white underparts. No dark belly patch or distinct cap.

3. 3

   Bill Color

   Prominent yellowish-horn colored bill with a dark tip. This is a key distinguishing feature from many other shearwaters.

4. 4

   Underwing Pattern

   Mostly white underwing with a dark trailing edge and a dark patch at the carpal joint (bend of the wing). The extent of the dark primary patch can help distinguish from Cory's Shearwater.

5. 5

   Flight Style

   Characteristic long, effortless glides on stiff wings, often banking steeply over waves, interspersed with short bursts of rapid wing beats.

6. 6

   Vocalizations (at breeding colonies)

   Distinctive loud, wailing, and cackling calls ('a-WAA-oh') heard at night. This is diagnostic if heard in appropriate habitat.

Habitat & range

Biomes

Marine, Pelagic, Coastal

Geographic range

Breeds primarily on islands and coastal cliffs in the Mediterranean Sea and the eastern Atlantic Ocean (e.g., Canary Islands, Azores, Madeira). Non-breeding range extends across the Atlantic Ocean, reaching as far as the coasts of South America (Brazil, Argentina) and South Africa.

Elevation range

Sea level to coastal cliff nesting sites.

Preferred environments

Open ocean waters for foraging, and remote, predator-free islands or cliff faces for breeding. They prefer areas with strong winds for efficient gliding flight.

Behavior

Activity time

Diurnal at sea for foraging, but primarily nocturnal at breeding colonies to avoid predation by gulls and raptors, especially when coming ashore or leaving nests.

Feeding habits

Primarily feeds on small schooling fish (e.g., sardines, anchovies) and cephalopods (squid). They forage by surface-seizing, shallow diving, and plunge-diving. Often associates with fishing vessels to scavenge discards.

Social behavior

Highly colonial breeders, forming dense colonies on remote islands. At sea, they can be found singly or in loose flocks, often congregating at rich feeding grounds or around fishing boats.

Flight pattern

Characterized by long, powerful glides on stiff wings, interspersed with a few rapid wing beats. They utilize dynamic soaring to conserve energy over long distances, often flying low over wave crests.

Migration pattern

Long-distance migratory species. After breeding in the Mediterranean and eastern Atlantic, most populations migrate to the South Atlantic for the non-breeding season (austral summer), returning to breeding grounds in spring.

Territoriality

Highly territorial around their nest burrows during the breeding season, defending their immediate nesting site from conspecifics.

Breeding & reproduction

Breeding season

Typically from late March/April to October. Egg-laying occurs from late May to early June.

Nesting habits

Nests in burrows, crevices, or under boulders on remote, predator-free islands or steep coastal cliffs. Burrows can be self-excavated or utilize natural cavities. Nests are often lined with a few pieces of vegetation.

Clutch size

1 egg.

Egg description

Lays a single, large, white egg, often with a faint pinkish tinge when freshly laid.

Incubation period

Approximately 50-55 days, shared by both parents.

Fledging period

Chicks fledge after about 85-100 days, typically in late September or October. They are fed by both parents until fledging.

Parental care

Both parents share incubation duties and feed the chick. Parents alternate foraging trips, often spending several days at sea before returning to the nest.

Where to find

Field tips

1. Pelagic Trips. Join organized pelagic birdwatching tours that venture into offshore waters where these birds forage. Look for them following fishing boats.
2. Night Observation (Breeding Colonies). If visiting islands with breeding colonies, listen for their distinctive calls at night. Observing them coming ashore or leaving at dawn/dusk requires careful, non-intrusive approaches and often permits.
3. Scan the Horizon. When at sea, continuously scan the horizon with binoculars for their characteristic gliding flight. They often fly low over the water.
4. Look for Feeding Frenzies. Scopoli's Shearwaters often congregate with other seabirds and marine mammals at feeding frenzies, indicating a good food source.

Similar species

Quick facts

Primary Habitat:

Open Ocean, Remote Islands

Diet:

Fish, Squid

Breeding Strategy:

Colonial, Monogamous

Migration:

Long-distance Trans-Atlantic

Vocalization:

Nocturnal, Wailing Calls at Colonies

Fun facts

• Scopoli's Shearwaters are known for their incredible navigational abilities, returning to the same nesting burrows year after year after migrating thousands of kilometers.
• The 'Zovoj' name is often associated with the mournful, wailing calls heard at night from their breeding colonies, which can sound eerie in the darkness.
• They are one of the deepest diving shearwaters, capable of reaching depths of over 30 meters to catch prey.
• Like other Procellariiformes, they have a specialized gland that allows them to excrete excess salt ingested from seawater, enabling them to drink saltwater.

Scientific classification

Kingdom

Animalia

Phylum

Chordata

Class

Aves

Order

Procellariiformes

Family

Procellariidae

Genus

Calonectris

Species

Calonectris diomedea

Explore the Scopoli's Shearwater