Andy Frank

Tuesday, September 11, 2018

Long-tailed Jaeger on Sauvie Island

Initially identified as a Parasitic Jaeger, consensus is that this is a Long-tailed Jaeger.  Appreciate comments below posted by Russ Namitz regarding this bird.

"I would call this bird a dark juvenile LONG-TAILED JAEGER.

Features that I look for on young birds like these surprisingly include the undertail coverts.

1) Undertail coverts are neatly & boldly barred black and white versus cinnamon in Parasitic.

2) Crisp whitish barring on upperside of bird (all wing coverts, scapulars, etc) versus cinnamon in Parasitic.

3) Bill nail (tip) of mandible is long and hooked and the black bill tip is almost half the length of the bill versus less than half in Parasitic.

4) Three white primary shafts, including rachis(center of feather) versus 4 to 5 white primary shafts shown by Parasitic.

5) Bill is short and stubby and head is small and rounded in appearance."


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