ML610537446

Age

Not specified

Sex

Not specified

Observation details

Juvenile bird. Probable Parasitic. Young jaegers are particularly viable and notoriously difficult to separate. However, the several keys features and the overall GISS of the bird points pretty strongly toward Parasitic. Longer bill shape than expected of a Long-tailed Jaeger. The upper side of primaries very clearly shows at least 3 white primary shafts that are majority white. (Two more showed a some pale at base also, not sure if that is countable). Parasitic usually show 3-5 white shafts. LT almost always has only 2 white primaries for whole length of shaft. The bird today was quite cinnamon (rather than cold gray) colored; including the nape, in the underwing coverts, undertail coverts and rump. This is typical of Parasitic. The underwing "flash" appears very consistent with Parasitic; broad and uninterrupted. Pomarines are known for their "double" flash appearance. LT underwing flash is often disrupted with dark "finger" appearance. This bird also appeared less lanky, long winged, and bulkier than a Long-tailed. Its flight style was not tern-like which LT Jaegers are known for. John Davis was also present and took better images. His eBird checklist will likely be a better reference for ID. Was primarily on Washington side but flew up the river repeatedly and floated down in both. Pomarine are super rare inland but there was a confirmed juv up the river a month ago or so (For what it's worth, Poms are apparently also know for being late migrants. Often in Oct/Nov.). They should show 5-6 white primary shafts and double flash on underwing lining.

Technical information

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