The First Sign of Spring

Not every bird comes to Union Bay, so sometimes Union Bay Watch goes to the birds.

These young Great Horned Owls were photographed earlier this week in the Nisqually Wildlife Refuge. GHOs are the most widespread owl across North and South America. Although only about half the weight of a Bald Eagle the grip of their talons at 300 psi is said to be nearly equal to the Bald Eagle's grip. At night the GHO is very close to the top of the food chain.

There are very few birds that raise their young in the middle of winter. Feel free to offer theories for why this happens in the comments section below, it could make for a very interesting discussion.

Even at just a few weeks old these birds are very alert. In this photo they focus and track a helicopter as it flies over. Notice the "horns", actually tufts of feathers, are erect on the bird to the left, this might be a reaction of alarm. Note: These horns are not their ears either. Their ears are asymmetrically located on the each side of their heads (See Update below) to allow them to "triangulate" with sound as well as sight. 

It can actually feel a bit alarming when their focus shifts to you...

...even when you know they cannot fly.

It is also interesting to note the difference in the size of the pupils. 

The bird on the left is focusing on something in shade among the trees while the bird on the right attempts to focus on the backlit helicopter. Obviously the wider pupils are drawing in more light. It would be very interesting to see the size of the pupils when these birds are hunting at night. 

Here is one more example.

The bird in front could be called, The Young Hunter, clearly the instinct is strong in this one.

These birds are so naturally fit to hunt that their tongues appear to be grooved to they can be used in combination with their beaks. They will become silent hunters in the night. Sometimes taking creatures that weigh more than they do. In these situations they may have to leave the body where it lands and then return to feed.

In spite of their hunting instincts right now these birds can look very young, soft, fuzzy and cute.

But they are growing wings that may end up spanning as much as five feet.

(Just like everyone else in the Northwest they have a "moss-on-the-roof" problem.)

In any case for the moment they can look very sweet.

In the next couple of weeks if you happen to find yourself south of Tacoma and passing by the NWR you should make the time to stop and check on these beautiful creatures. Soon they will be wandering out on to near by limbs and then spreading their wings.

Smile this is truly the first sign of spring!

Larry Hubbell

Note: I have heard of GHOs being seen in the south end of the Arboretum, although I have never seen one there. Feel free to let us know if you are lucky and happen to see one anywhere near Union Bay.

Updates:                                                                                                                  2-17-13

1) In the comments below Karen reports the owlets have left the nest and therefore are now fledglings.

2) I just saw a very well done video of the owlets. If you would like to take a look click on the link below:

http://danstreiffert.smugmug.com/Other/Recent-Photos/5478949_xWhQLX#!i=2369086402&k=H9sKBvW

Dan, Very nice work! Larry

Update:                                                                                                                  2-18-13

Peter Reshetniak, President of the Raptor Education Foundation ( http://www.usaref.org) sent in these comments.

"...Thanks Larry- is there a citation?  Wiki is a mile wide and inches deep on many things.  However, even this you can find  as per  hearing asymmetry in owls, and Bubo v. as well as Asio o. do not have asymmetry, i.e. both the Great-horned and screech have symmetrical ear placement (Payne, Roger S.. Acoustic Location of Prey by Barn Owls (Tyto alba). J Exp Biol. 1971; 54, 535-573 ) The owls with asymmetry appear to be the deeply nocturnal species, such as the barn owl..."

The answer to Peter's question is there is a reference however without access to the book I cannot be sure that the author was not misread or misquoted. The reference was, "Owls of the World by Konig, Weick & Becking. Yale University Press (2009), ISBN 0300142277".

"... I doubt that the PSI quote has any experimental data to support it (this is science by consensus ).  There is data on the dragging power of certain eagle species, plus the impact force is a simple mathematical calculation, but actual psi would require a very complicated machine to record the “crushing force.” and so far, I have found no such experimental evidence for any raptor.—whatever that is worth..."

The wiki reference for the 300 psi is,

http://lubbockonline.com/stories/032606/gue_032606062.shtml

"...As far as timing on egg laying, hatching, and fledging (all my intimate data is Colorado based) we will see 3 month variations in all of those categories with Bubo.  There is very little  “normal” in some things, as a wide variety of  unknowns, and knowns can change and alter some of those times/schedules.  I would imagine your part of the world is not much different.  The birds haven’t read about what they are supposed to do, or when they are supposed to do it.  Again,  if it is in Wiki, and if you cannot get a verifiable citation, and check the citation, it may be quite spurious.  I spend time in the Seattle area, and appreciate what you are working at, so watch Wiki as a source, it is quite broad, but its depth can hurt your head when you dive in..."

Thank you to Peter for the information and concern with the truth. In the future I will follow the links at greater length and look harder for the science behind the claim. Thank you especially for your knowledge about the timing of egg laying. It will be very interesting to follow up next year and see how much the timing changes. So much to learn and so little time. :-)

Larry