Monday, October 25, 2010

Boulder County Sandhill Crane

Fall weekends can get booked full amazingly fast. The last couple of days were spent at the homecoming game for CU, and split between frustrating NFL games on TV and a long overdue garage cleaning. When weekends pass in a flash I check my birding inbox with mixed feelings. Usually, I will find that local birders have been out seeing spectacular birds, which are now long gone. Today I was pleased to see that a juvenile Sandhill Crane that had been seen through the weekend in Boulder County was still around this morning. As I wrote in my very first blog entry, the Sandhill Crane had a big part in my introduction to this pursuit, and since that first glimpse I have been unable to relocate it for its place on my Colorado list. So I took an early lunch and as the witness quality photos demonstrate I was successful in tracking down the bird.

Unfortunately I had somehow gotten my aperture set to a small opening, which kept these pictures from being anything special. A small aperture requires a longer exposure to allow enough light to reach the sensor - the camera adjusted for that, capturing still objects nicely, but blurring any motion. The unexpected result were some still bad photos, but ones that were tantalizingly close. My panning was right to almost freeze the still parts of the bird while blurring the background - but close only counts in horseshoes and hand-grenades.

All my photographic failings aside; there was an interesting interaction that I replied back to CObirds with:

After seeing the report that the Sandhill was still present early this morning I decided to head over myself to see if I could relocate it. True to the directions the juv. Sandhill Crane was feeding in the wheat field. I was afraid it was going to leave just as I spotted it, because just as I pulled to a stop a N. Harrier headed low across the field directly towards the Crane. To my relief the two birds largley ignored one another. A few minutes and some poor photos later another bird spooked the Crane. I kept the crane in frame as it flew, and then tried to ID the culprit who chased it off. From my impression and close looks at really bad pics it appears to have been a 3rd year Bald Eagle. I watched the two fly east and drop down behind the first group of trees to the east. After a few minutes I did see two large birds rise from that area, the presumable Sandhill heading SSE, possibly turning back towards the S as I lost it.

Does anyone have experience with the frequency of Bald Eagles taking Sandhill Cranes in migration? Would other area species attempt to snack on prey that size?
Has anyone else seen similar interactions with this bird?

Thanks and good birding!

The response was encouraged by the original poster when I wrote to thank her for her update this morning. From my previous reading I had kind of expected that this was a young bird, attacking prey that was a bit on the large size for its regular menu. That was very shortly confirmed as a possibility by a well-respected Boulder birder. Several other birders have responded, confirming that while Bald and Golden Eagles will occasionally prey on Sandhill Cranes, they are generally taking the sick, injured or weak. Having witnessed this interaction I tend to believe this was just a case of two youngsters working out their respective places on the food chain.

Perhaps this bird has already returned to its field to continue to fuel up for the continued flight south. If so, hopefully this Eagle will focus on more appropriate prey, leaving the Crane in peace.

Maybe then I will be able to add a few better photos of this species!

2010 Count: 202
Lifetime: 245


  1. The motion shots are GORGEOUS....I love them!!

  2. You know, those action shots are pretty darned attractive! I'd call them keepers!

  3. Thanks for the kind feedback. I do like the potential, just really wish that last one had frozen the bird's head. Glad to know they are enjoyable even so.