Monday, May 5, 2014

How to Eat a Kangaroo Rat: If You are an Owl

One of the Great Horned Owl nests I've been monitoring in recent months is on a power pole in the sagebrush desert on the west side of Utah Lake. It is about 35 minutes from my home so I've been limited in how frequently I've been able to visit the site. A month had passed since my last visit so I was curious to know if the two owlets had "branched" out of their nest. I made the drive to the site a few nights ago and saw both owlets standing on the crossbars. They had grown significantly since my last visit and had clearly reached their branching stage. The crossbars of the power pole that cradled their nest were the only options for branching since there are no trees of which to speak in the area. Mom spends her day on the pole close to the owls. I'm not sure where dad roosts during the day, but he's prompt in delivering the first meal of the evening each night just after the sun sets.

I arrived at the nest site just as the sun was setting so I set up a ladder in the bed of my truck and put a bean bag on top of the ladder to provide support for my camera.  The tripod would not have been high enough to allow a straight-on look toward the owls. I was well over fifty feet from the power pole.  Dad was right on time and flew in from the east as he'd done during my previous visits.  I watched his silhouette fly in with some sort of mouse gripped in his talons. He gave that mouse to the owlet on the far side of the pole so I was unable to view it well from my vantage point. The second owlet waited patiently for its meal. And it was well worth the wait--for the owl and for me.

I captured some video of both owlets killing time and a long segment demonstrating how the second owlet consumed an Ord's Kangaroo Rat. The video is almost ten minutes long. I personally find all of their behaviors on the video interesting, but here are some behaviors with the timing of each within the video if you want to pick and choose what you view. BE SURE TO VIEW THE VIDEO IN 1080p HD for the best quality. You can make that selection in the bottom, right-hand corner of the YouTube screen when it loads. You can click on full screen for a better view as well. You may need to set to 1080p HD and then restart the video for a clear image.

During the first minute:
The owl that will eat the kangaroo rat will walk the plank, so to speak, turn it's backside away from the nest (toward the camera), flap its wings, and eject the digested part of a previous meal. These owls somehow know from an early age to turn and defecate away from the nest.

At the minute mark:
Dad arrives with the kangaroo rat and then flies away. The owlet turns toward the camera with the rat in its beak and begins a slow process of inspecting the rat with soft bites and nipping that makes me wonder if it is trying to figure out how to approach it. It nibbles the rat from a front foot and then head to tail without seriously trying to eat it. This is where we get some views of the field marks that help to identify the kangaroo rat as an Ord's Kangaroo Rat. The second owls seems curious buts keeps it distance.

About 3:30 in the video:
The owls begins serious attempts to eat the rat. Sometimes the owl tugs so hard at the rat with its beak that it nearly stumbles when part of the rat breaks loose in its beak. Both owls seem to look out into the darkness at times making me wonder if they hear or see a parent nearby.

About 6 minutes in:
The owl is beginning to make real progress with the meal.

About 7:30
The rat's head and insides are consumed. This is followed by the owl swallowing all but the tip of the rat's tail. The dark hairy tail tip dangles from the owls mouth for about thirty seconds before it finally gets swallowed. Mom shows up and all three turn toward the camera after the second owl stretches, flaps, and stretches its wings.

View the video in HD 1080p. You may need to set at 1080p and then restart the video for best quality.

So that nearly-ten-minute video took hours to upload to YouTube. I realized afterward that I somehow edited out a short section I thought was kind of interesting. The first owlet seems to grow bored by the other owlet's slow approach to eating. It blinks slowly and then gives a wide-mouthed yawn. Here's that short little clip.

I find birds of prey to be very fascinating. I've really enjoyed studying two separate Great Horned Owl families and look forward to watching some diurnal raptors raise their families in the next month or two.

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