Sunday, December 8, 2013

Sharp-shinned Hawk--Accipiter striatus

Sharp-shinned Hawk--note the large eyes. USFWS National Digital Library.  Photographer--Donna Dewhurst

Sharp-shinned Hawks--called "Sharpies" by birders--are small, very agile hawks that belong to a genus of birds called accipiters.  Sharpies are about the size of a blue jay.   These little hawks prefer forests, parks, and the wilder areas, but on occasion can be seen in backyards.   Differentiating these little accipiters from Cooper's Hawks--another accipiter--is one of the challenges of birding.  They look very much alike. 

Sharp-shinned Hawk in hand.  Note the thin, long toes on the Sharpie and the small head.
USFWS National Digital Library.  Photographer--Donna Dewhurst

The picture above gives you an idea of the size.  These are not large raptors.  Sharp-shinned are smaller than Cooper's Hawks, but there is almost an overlap in size.  The difference in male and female raptors is generally the size.  The female is larger than the male.   So the larger female Sharp-shinned Hawk may be very similar in size to a smaller male Cooper's Hawk.   There is a bigger difference in the size of male and female Sharpies than any other species of raptor.   Birds of North America quotes a study by Snyder and Wiley (1976) that found male Sharpies on the average have only about 57% of the body mass of a female Sharpie.    

 Sharp-shinned Hawk--Wikicommons. 
Ilona Loser
Notice how the widest part is at the shoulders.  It has a kind of body-builder or Dolly Parton look to it.   A Sharpie is a bit chesty.  Also, note the hooded look.  The Sharpie has a dark crown.  The dark color continues down the nape of the neck  down onto its back.  This is different than the smaller cap on the larger and flatter head of the Cooper's Hawks.  The Sharpie's head is rounder than the Cooper's.   In addition, the Cooper's has a kind of a messy, crest-like feather thing going on  at the back of its head that is visible on occasion.  The Sharpie has no crest-like feathers on its head.

Juvenile Sharp-shinned Hawk--Wikicommons--juveniles have yellow eyes.  Photographer--Matt edmonds.

Even this juvenile Sharpie above has the high chest, and small head. 

Juvenile Sharp-shinned Hawk--Wikicommons--Denali National Park and Preserve

The chest being wider at the shoulder is harder to see here on this juvenile Sharpie above, but the very thin toes with the long center toe are evident. 

Juvenile Sharp-shinned Hawk in flight--Wikicommons.   Note the long, narrow tail.  Photographer--Steve Berardi

Note the small head, rounded wings, and straight tail tip with the notch on the Sharpie above.   In Orange County, CA, we usually see Sharpies in migration season which is fall and a bit into winter.   They migrate alone or in small groups.  Occasionally with other species of hawks.  Sharpies tend to migrate along areas where they would most likely live and hunt:  forests and areas with conifers.

Sharp-shinned Hawk--Wikicommons.  Photographer--
H. Petruschke

The long, slim tail and the rounded wings help the Sharpie maneuver in tight spots like forested areas and undergrowth.  I was once in the nature center at Mile Square Park in Fountain Valley and was startled by a small Sharpie, probably a male, flying fast and low to the ground along a curving trail between the bushes.   He flashed by me and straight into the undergrowth like he was shot out of a canon.  He seemed incredibly small, but there was no doubt at all that he was a very small accipiter based on the shape and the coloring.  

Smithsonian Migratory Bird Center video by George Jameson.  Note the long middle toe, the hooded appearance, and the large eyes, and how the chest is largest at the shoulders.   Note that the eyes are not yet red, and so this is a juvenile Sharpie.

Sharp-shinned Hawks are the stealth bombers of the bird world.    Any place, any time is right for a surprise attack.   They can begin an attack from a concealed perch in a tree or shrub, or on the wing.   And their prey can be perched or on the wing as well.   When opportunity strikes, the Sharpie strikes, and holds tight with its dainty, but long, deadly  talons.   The Sharpie attacks in a horizontal plane, not a vertical one.   It approaches fast through the foliage toward its unsuspecting prey.   It either succeeds, or it moves on quickly to another target.   Birds are its most frequent victim by far, but it also takes a small amount of mammals, reptiles, insects, and amphibians. 

Sharpie Front and Back from the Delaware Nature Society

Major Field Marks--Sharp-shinned Hawks

Small head, short neck

Large red or orange eyes for adults.  Large yellow eyes for immatures and juveniles

Hooded appearance--black on the head continues down the back.

Largest width at shoulders resulting in a top-heavy look
Thin toes.  Long middle toe.

A very thin, white tip on the end of its slim, squared tail.

From the Smithsonian Migratory Bird Center.   Check out those field marks.

To be ready to identify Sharpies and Coopers Hawks, I would suggest you study your bird guide and the articles listed in the "Resources and Links" section at the end of this post.   Good birders learn to recognize bird species the way you would recognize an old friend--repeated encounters.  We begin to recognize the color, the size, the shape, the way they move and behave, and their voice.   Even their favorite foods and hangouts.   Make friends with Sharpies by observing and studying them both in real life, and in bird guides, photographs, and videos.

So when you encounter an accipiter, be prepared.  Know your Sharpies.  Know your Coopers.  And then do your best.  It is a challenging ID.   Have fun birding in Orange County, California!

OC Birder Girl Links

Hawks and Eagles of Orange County

The Owls of Orange County

Bird Walks and Nature Programs in Orange County, California

Birding Hot Spots in Orange County, California

Resources and Links

10,000 Birds--Cooper V. Sharpie

Article about differentiating Coopers and Sharpies.

All About Birds--Sharp-shinned Hawk

A Sharp-shinned Species profile from Cornell's all About Birds.  

Animal Diversity--University of Michigan--Sharp-shinned Hawk

Lots of detail in their profile about Sharpies. 

Audubon--Sharp-shinned Hawk

Profile and photographs.

Carolina Bird Club--IDENTIFICATION PRIMER: Accipiters

Great resource.  Article addresses Sharp-shinned, Cooper's Hawks, and Goshawks.   Lots of details and pictures.

The Canadian Peregrine Foundation--Raptor Identification--Sharp-shinned Hawk

 Profile with an ID gallery of photos.
-shinned Hawk

Delaware Nature Society

Great shot of a Sharpie.  Also check out their Ground-hunting Sharp-shinned Hawk

The Internet Bird Collection--Sharp-shinned Hawk

Great collection of bird videos.  Watch the videos of the sharpies.  Get a feel for them. 

International Bird Rescue--Friday Rounds: Sharp-shinned Hawk

Sharp-shinned Hawk gets a bath after getting glue from a glue trap stuck in its feathers.  Gives a good idea of the size.

Macauley Library Sharp-shinned Hawk Videos

Videos of Sharp-shinned Hawks from the Macauley Library.

Mango Verde--World Bird Guide--Sharp-shinned Hawk

Mango Verde page about the Sharp-shinned Hawk.

National Geographic--Sharp-shinned Hawks

Detailed information regarding Sharp-shinned Hawks including sketches.

The Nature of Delaware--Sharp-shinned Hawk

Sharp-shinned Hawk visits.  Nice shots and video.

Portland Oregon Backyard Birds: Sharp-shinned Hawk

Great post about a Sharpie visiting a backyard in Oregon.  Excellent pictures.  Note the widest part of the breast is at the shoulders.  And the hooded appearance. 

Project Feeder Watch--Sharp-shinned and Cooper's Hawk

Detailed guide to telling the two similar accipiters apart.

Orange County Register--Sharp-shinned Hawks by Pat Brennan

Brief article by Pat Brennan about the influx of Sharp-shinned Hawks during migration.

Orange County Register--Tallying the Tail Feathers by Shawn Price

Article about the Christmas Count.  Good picture of a Sharpie in Laguna Woods.

South Dakota Birds and Birding:  Sharp-shinned Hawk

Good Sharp-shinned Hawk article and gallery. 

Teton Raptor Center:  Sharp-shinned Hawk

Profile of Sharp-shinned Hawks.  Photos.  

Vimeo Google Search--Sharp-shinned Hawk

Here is a search on Vimeo for Sharp-shinned Hawk videos.  Usually high quality.  Look especially for Don Desjardin videos.  His videos are excellent, and he knows his birds.

Virtual Birder--Accipiters 

Gallery of Sharp-shinned Hawks, Cooper's Hawks, and Goshawks.   All in flight.   

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