Wednesday, November 19, 2014

My First Red-shouldered Hawk

On November 16, 2014 I observed my first Red-shouldered Hawk (RSHA) on Cape Sable Island, Shelburne County. This buteo was flying Northeast over the road near the intersection of the Centerville South Side Road and the Daniel's Head Road.
Red-shouldered Hawk - Cape Sable Island - November 16, 2014.

From the mid-1960's until the end of 2010 there have been 106 reports of this bird in Nova Scotia. Many of the 65 fall sightings have occurred during large hawk movements over Brier Island. [All the Birds of Nova Scotia, Ian McLaren]
There are 5 subspecies of RSHA but three of them are essentially indistinguishable from one another and they occupy most of the eastern states. Southern Florida and California birds are separable from the eastern subspecies group. [Hawks in Flight, Dunne et al.]
All About Birds
This hawk most closely resembles the expected eastern subspecies group. A juvenile California RSHA would have thick black bars on the tail and dark rufous underwing coverts. The Florida subspecies would not show such an evenly patterned underside and would have smaller light bands and wider dark bands on the tail. [The Sibley Guide to the Birds 2nd Ed, Sibley]
Juvenile Red-shouldered Hawks are somewhat similar to juvenile Broad-winged Hawks (BWHA). There are a few field marks that allow an observer to easily differentiate between both species given clean views. 
Both have quite different wing tip shapes. The BWHA shows pointed wings reminiscent of a candle-flame. The wings of a RSHA are described as looking like a rectangular plank. BWHAs show narrow dark tail bands in comparison to the RSHAs evenly wide light and dark tail bands. The pale crescent windows produced by the translucent outer primary bases are only found on RSHAs. [Hawks in Flight, Dunne et al.]
The Sibley Guide to the Birds 2nd Ed, Sibley (added annotations)
The annotated photo of my Nov. 16th RSHA below shows all of the field marks that differentiate it from a BWHA.
Red-shouldered Hawk with annotations

1 comment:

  1. Great post, Alix. Your photo looks like a live action version of the Sibley's. Well done!