IBRC 56-B-09

Idaho Bird Records Committee Rarities Report Form

Species: Broad-winged Hawk, juvenile

Reporter: Cliff Weisse
4125 Beaver Springs Rd.
Island Park, ID 83429
cliffandlisa@octobersetters.com
Other Observers: None

Date of Observation: 5 October 2009 @ 10:50 AM
Date Report Prepared: 6 October 2009

Locality of Observation: Near milepost 371 on US 20, about 11 miles south of Island Park
Habitat: Broken Lodgepole Pine forest with large open areas.

Conditions:  Bright overcast with light snow and light wind.  Ground barely covered with snow.  Distance between 300 yards and 30 yards.  Duration of observation about 2 minutes total.  Underside of bird lit up very well by light reflected off snow.  Visibility and color discernment excellent.

Did you take notes… Yes, immediately after the observation
Did you consult a field guide or other reference work?  No

Description: The bird was first seen on the east side of the road soaring in a tight circle.  I immediately knew it wasn't a Red-tailed which, at this date, made it an interesting bird.  As I approached it turned so I could see the underparts well and I recognized it as a Broad-winged because of the dark head and white underlings with dusky trailing edge.  I pulled over a few hundred yards down the road (as soon as I could get the truck and camp trailer stopped and off the road).  The bird then came past me on the west side of the road alternately flapping and soaring.  The wing beats were obviously quicker than Red-tailed Hawk and it soared in very tight circles.  Shape overall was very much like a Red-tailed.  The wings had a very straight leading edge and the trailing edge bulged outward slightly through the secondaries, but not as much as on an adult Red-tailed.  The wing tips were pointed when soaring, much like Swainson's but unlike Red-tailed, Red-shouldered or Rough-legged.  From below the tail was pale with narrow dark bands and a wide subterminal band.  Upperparts were dark brown but not seen well so I wasn't able to see if there were and pale markings in the covers/scaps/secondaries.  The underparts were whitish and moderately streaked with heavy (wide) dark brown streaks on the belly and breast, more heavily on sides than in center but still more white than brown.  Head appeared entirely dark brown with white throat and dark malar line that extended into the streaking on the breast sides.  The underwings were entirely whitish, lacking any contrasting dark markings on wrist (tips of primary coverts) or patagium, but with obvious fairly wide dusky trailing edge on primaries and secondaries.  There were faint dusky bands visible on the secondaries but overall the underside of the wing looked white.  Also the underwings coverts had slightly contrasting tannish tips that formed a very indistinct band on underwing.  Undertail coverts white.  

Behavior: The bird was intermittently flapping and soaring while always heading south, apparently migrating through the area.  It was very low, not far above the trees and it soared in tight circles, much smaller circles than typical for Red-tailed Hawks or those seen later the same day.

How and when did you positively identify the bird, and what clinched the identification for you?  
I recognized the bird as a Broad-winged the first time it urned and revealed the underside because of the dark head and white wings with dark trailing edge.

How did you eliminate similar species, and what were they?  
-Red-tailed Hawk has blunt or square tipped wings, dark patagium and tips of under primary coverts, typically a dark throat and lacking malar line when they do have a white throat.
-Red-shouldered has dark throat in all plumages and square tipped wings.  It also has contrastingly barred wings that are overall dark from below
-Swainson's Hawk has completely dark primaries and secondaries in all plumages.
-Rough-legged has long straight cut wings with a square tip, pale base of tail, and a large square blackish mark on the wrist in all light/intermediate plumages.  In addition all light/intermediate morphs have a pale head.
-All accipiters have short wings with rounded tips and a long tail with even width bars.

Experience with this species: I've seen a few in Idaho and I've been to Sandy Hook Hawkwatch in NJ on two days when there were BWHAs visible almost constantly and I would say I have limited experience with this species.  I see Red-tailed and Swainson's almost every day from Apr-Sept and Rough-leggeds regularly during the winter months.  

General experience birding: 16 years

Were photo(s), video, and/or audio obtained by you?  No