Parasitic Jaeger in St. Louis County
2011-09-09

'Rare Regular' in Minnesota

Composite image of juvenile Parasitic Jaeger flying over Lake Superior at approximately 5:15 PM under clear skies with light NE winds. All four images in this composite were taken from the beach at 43rd Street, Park Point, Duluth, and all four images were adjusted by the same amount to correct for underexposure. Note bill size and shape, width of wing at root compared to distance from trailing edge of wing to tail tip, dramatic pale flash at base of underwing primaries (but no corresponding flash on greater under wing-coverts), and shape and extension of central rectrices beyond tail tip. Juvenile Pomarine Jaeger shows a larger, dark-tipped bill, broader inner wings, a "double underwing flash", and its central rectrices are typically thumb-shaped nubbins that barely extend beyond the tail tip. This jaeger's agility while in pursuit of Ring-billed Gulls and its smaller wingspan compared to an average adult Ring-billed Gull were also noted. Its plumage matched that of a juvenile Parasitic Jaeger that I watched and photographed off parking lot #1 at Wisconsin Point earlier this same morning; at Wisconsin Point, the juvenile appeared to be identical in size and wingspan to an adult light morph Parasitic when they were flying side by side and chasing one another. Tim Oksiuta from Ashland had reported an adult and juvenile parasiticus at Wisconsin Point yesterday morning (Thursday, 8 September) and I saw this same juvenile near the Sky Harbor Airport on Park Point earlier this week (Tuesday evening). So far, the adult has only been seen on the Wisconsin side of the state line.

Peder H. Svingen