Life On and Off an Acreage

In-sights into moving from an Acreage back to Town, plus a few things I find of interest.

Two things that horses are scared about:

1. Things that move
2. Things that don't move

May 17, 2017

A Day With the Hawks

I happened to see this hawk on the edge of a field. This is him taking a squirrel up onto a field. Caution! Some pictures are a little graphic!

Covering his kill, and daring anyone to interfere.

He believed in posing for the camera.


It's tough being a squirrel with him around!



He finally took the rest to a tree to finish his dinner




Alica said...

You got some great close ups! I know, it's hard to watch sometimes, but it's fascinating how God has designed all these animals/birds to survive without our help!

Ian H said...

It turns out that this is a Harlan's Red Tailed hawk, thanks to the experts at the Natural Resources.

Michelle said...

These are excellent! You really got some great close ups. Actually nice to see nature, in action!

Ian H said...

From The Guardian

Response: This is an dark morph immature Harlan's red-tailed hawk, Buteo jamaicensis harlani. This (sub)species has been elevated to full species status ("split") and subsumed into the red-tailed hawk taxon as a subspecies ("lumped") several times now, reflecting our lack of understanding about this taxon and our ongoing confusion as to what is a species. Currently, this subspecies is a candidate for a split again, a decision that will likely be enacted quite soon. When that occurs, this species will once again be known as Harlan's hawk, Buteo harlani. However, until a rigorous DNA study has been completed on the red-tailed/Harlan's/Krider's hawk species complex, these taxa will be split and lumped repeatedly in the future.

Before we get into the nitty-gritty of identifying this bird, it's helpful to make an educated guess as to the bird's approximate age. Fortunately, this is probably the easiest trait on this bird to interpret. The individual in this photograph has pale yellow eyes, indicating this is an immature bird since adults of both taxa have pale brown eyes.

Harlan's hawks breed in Alaska and northwestern Canada, and winter in the western USA and on the southern Great Plains of North America. This very dark raptor has a marbled white, brown, and gray tail instead of rufous.

The bird in the photograph is very dark, so how do we know it's a Harlan's hawk and not a dark morph red-tailed hawk? Here's a few characters that help with this tricky ID:

immature Harlan's hawks have dusky tails, rarely with any rufous colouring. In rare individuals, if there is any hint of rufous colouring, it is present as a pale wash. Roughly half of the adults will have at least some rufous colouring on their tails, typically as a band near the tip
Harlan's hawks have many dark bands on their tails, with an especially bold subterminal tail band
Harlan's hawk wingtips clearly do not reach as far as the end of their tails when perched
dark and intermediate morph Harlan's hawks can be distinguished by the amount of mottling on its upperwing coverts: dark morphs lack this mottling
the dark areas of Harlan's hawks are a blackish brown, lacking any warm rufous tones, except perhaps in the tail
Harlan's hawks have variable amounts of white speckling, whilst red-tailed hawks have buff speckles
some research indicates that Harlan's hawks have shorter tarsi than red-tailed hawks, but I was unable to track down and cite this work for you (also keep in mind that such measurements are impossible to get in the field on a live bird anyway!)
I also should point out that Harlan's hawks have dark, intermediate and -- rarely -- light morphs, as do red-tailed hawks. If that isn't complicated enough for you, Harlan's hawks and red-tailed hawks will interbreed where their ranges overlap, producing intermediate forms that run the gamut in colouring.


Additional reading:

"Extreme variation in the tails of adult Harlan's hawks" by William S. Clark. (January 2009). Birding magazine [free PDF, and here's the photographic guide, including five additional photographs not seen in the original article; free PDF].

"Red-tailed Hawk Identification" by Dan Tallman. (December 2009). South Dakota Bird Notes [free PDF].

"Dark red-tailed hawks" by Jerry Liguori. (October 2004). Birding magazine [free PDF].

"Field identification of some Red-tailed Hawk subspecies" by James W. Lish and William G. Voelker. (Summer 1986). American Birds 40(2):197-202 [free PDF].