Sighting Record for Utah

Common name:	Parasitic Jaeger
Scientific name:	Stercorarius parasiticus
Date:	12 October 2013
Time:	about 10:00 am - 12:00 pm
Length of time observed:	1 hour 45 minutes
Number:	1
Age:	Adult
Sex:
Location:	Provo Airport Dike, Southwest corner
County:	Utah
Latilong:
Elevation:	4500 ft
Distance to bird:	100 ft to 1/4 mile
Optical equipment:	Kowa spotting scope, 8x50 Binoculars
Weather:	sunny, calm
Light Conditions:	good
Description: Size of bird:	A little smaller than a California Gull.
(Description:) Basic Shape:	Gull Shaped.
(Description:) Overall Pattern:	Brown with white belly, neck and wing crescents.
(Description:) Bill Type:	Gull-like, dark.
(Description:) Field Marks and Identifying Characteristics:	Light morph adult jaeger. A gull-like bird a little smaller than a California Gull. Dark brown wings, hood, rump, undertail coverts, tail and breast band. White belly, chest, neck, throat and white at the base of the primary feathers on the top and bottom of the wing. All dark bill. Dark hood did not cross below the bottom of the bill. Two central tail feathers extended about twice the length of the rest of the tail feathers and tapered to a point. See photos.
Song or call & method of delivery:	None
Behavior:	Most of the time it was just sitting on the water, very far from shore. It chased gulls a few times. Our first good view of it was when it attacked a gull in midair, twisting up from under the gull with it wings and tail spread. It also skillfully soared in a thermal over land, rising quickly and out of sight.
Habitat:	Large wide open lake. It spent most of the time floating on the water very far from shore.
Similar species and how were they eliminated:	Pomarine Jaeger - On an adult light morph Pomarine the dark cap would extend below the bill onto the malar area. The bill would be bicolored with a dark tip and pale base. A Pomarine would look bulkier overall and an adult would probably have longer, blunt-tipped central tail feathers. Long-tailed Jaeger - An adult Long-tailed would have a uniform dark underwing, a grayer belly and probably longer central tail feathers. No other Gulls or Skuas are patterned like this bird was.
Previous experience with this & similar species:	I have never IDed a Parasitic Jaeger before. I have seen a couple of distant jaegers that I wasn't confident enough to ID. They were probably Parasitic. I have seen a young Long-tailed Jaeger once. In other words, very little experience with jaegers.
References consulted:	Sibley Guide.
Description from:	Notes made later
Observer:	Eric Huish
Observer's address:	850 E 100 N Pleasant Grove, UT
Observer's e-mail address:	**
Other observers who independently identified this bird:	Keeli Marvel, Milt Moody, John Crawley (photos), Carlos Caceres, Mark Thal, Robert Brown and Mahauni Date_Prepared: NO_additional_Materials: No_additional_Materials Photos: Photos Additional_Comments:
Date prepared:	13 October 2013
Additional material:	Photos
Additional_Comments:	Link to eBird checklist with additional sighting info -