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Photo: © Ian Davies eBird S46896675 Macaulay Library ML 107100071
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Pomarine Jaeger

Stercorarius pomarinus
Págalo Pomarino
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Song

Pomarine Jaeger

Appearance: The Pomarine Jaeger is a medium to large seabird with a powerful build, broad wings, and a distinctive pointed central tail feather (known as the "spoon-tail"). It has a dark plumage with a mottled brownish appearance and a pale head. In breeding plumage, the Pomarine Jaeger may show a more contrasting black-and-white coloration. Adults exhibit a strong, hooked bill and prominent pale wing flashes during flight. 
Habitat: The Pomarine Jaeger is a circumpolar species that breeds in the high Arctic and subarctic regions of North America, Europe, and Asia. During the non-breeding season, it migrates southward to offshore waters, where it spends much of its time at sea, far from land. The species can be found in a variety of marine habitats, including open ocean, coastal areas, and pelagic zones. 
Behavior: Pomarine Jaegers are skilled and opportunistic predators, often engaging in piracy behavior to steal food from other seabirds in flight or from the water. They are highly agile flyers, capable of performing aerial acrobatics and pursuing prey during foraging flights over the ocean. Pomarine Jaegers may also exhibit territorial and aggressive behaviors, especially during the breeding season. 
Breeding: Breeding pairs of Pomarine Jaegers establish nests on open tundra, rocky cliffs, or coastal islands in their Arctic breeding range. They typically lay 1-2 eggs in a shallow scrape on the ground and both parents take turns incubating the eggs and caring for the chicks. Pomarine Jaegers defend their nesting territories vigorously against intruders, including other seabirds and predators. 
Conservation Status: In Colombia, the Pomarine Jaeger is a rare and occasional visitor to the country's coastal waters during migration or at sea-watching sites.

Distribution

Pacific Coast: Along the Pacific Coast of Colombia, the Pomarine Jaeger may be occasionally sighted during migration periods or while foraging offshore. Key locations such as Buenaventura, Tumaco, and Isla Gorgona could potentially serve as sighting spots for this species.
Caribbean Coast: Similarly, the Pomarine Jaeger may be encountered along the Caribbean Coast of Colombia, particularly near coastal areas where the seabirds may concentrate for feeding or resting. Locations such as Cartagena, Santa Marta, and La Guajira could be potential areas to spot Pomarine Jaegers during migration seasons.
Offshore Waters: Pomarine Jaegers are known to spend a significant portion of their time at sea, far from land, where they forage on marine prey and engage in long-distance movements. Offshore pelagic waters off the coasts of Colombia, especially in areas with upwelling and productive marine ecosystems, could attract Pomarine Jaegers during migration.Islands and Archipelagos: Colombian islands and archipelagos such as the San Andrés and Providencia Islands, as well as the Malpelo and Gorgona Islands, could serve as potential stopover points or sighting locations for Pomarine Jaegers during migration or dispersal.
Islands and Archipelagos: Colombian islands and archipelagos such as the San Andrés and Providencia Islands, as well as the Malpelo and Gorgona Islands, could serve as potential stopover points or sighting locations for Pomarine Jaegers during migration or dispersal.

Taxonomy

The Pomarine Jaeger (Stercorarius pomarinus)

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Aves (Birds)
  • Order: Charadriiformes
  • Family: Stercorariidae
  • Genus: Stercorarius
  • Species: Stercorarius pomarinus

Vocalization

Calls: Pomarine Jaegers are known to produce a variety of calls that serve different purposes. Their vocalizations include both calls and sounds. The calls of Pomarine Jaegers are typically described as loud, harsh, and sometimes guttural or croaking in nature.
Alarm Calls: When threatened or disturbed, Pomarine Jaegers emit alarm calls to alert other individuals in the vicinity. These alarm calls are often intense and can convey a sense of urgency or danger.Territorial Calls: During the breeding season, Pomarine Jaegers may engage in territorial disputes with other individuals over nesting sites or resources. They use specific vocalizations to establish and defend their territories, signaling their presence and dominance.
Courtship Calls: In the context of courtship and breeding displays, Pomarine Jaegers may engage in vocal interactions to attract mates or strengthen pair bonds.Courtship calls are more subdued and melodious compared to alarm or territorial calls.
Flight Calls: While in flight, Pomarine Jaegers may emit distinct calls that serve as contact calls to communicate with other members of their species. These flight calls can help individuals maintain group cohesion or coordinate movements during foraging or migration.
 Interaction Calls: During interactions with conspecifics or other seabird species, Pomarine Jaegers may use a range of vocalizations to convey intentions, warnings, or social cues. Interaction calls can vary in intensity, pitch, and duration depending on the context of the interaction.