Wednesday, November 4, 2015

Harlan's Hawk: Winter 2013/14 Re-cap

I went for a short drive a couple of Saturdays ago to see if any northern raptors had made their way down to Utah County, Utah for the winter. I was pleased to locate two Harlan's Red-tailed Hawks during my short drive. One appeared to be a dark adult I have observed in the same location for several winters running. The second individual was a dark juvenile that allowed me to capture a few images, including the one below.

Juvenile Dark Harlan's Red-tailed Hawk Near Fairfield, Utah
Seeing the first two Harlan's Hawks of the season reminded me of a blog post I started nearly two years ago but never posted. I've decided to finally publish that post to share results of an informal study of Harlan's Hawks I started late in 2013.

Here's the post...

I shared a post about Harlan's Hawks late last October (2013) as I was anticipating their arrival from their breeding grounds of Alaska and northwestern Canada.  In lieu of observing these hawks on their distant breeding grounds I did the best thing I could do in terms of studying them in the field by searching for while they were wintering in the lower western states. In fact, my search for them was even smaller than the western states. It was essentially limited to Utah County, Utah. I located, photographed, and documented as many individual Harlan's Hawks as I could between November 2013 and April 2014. I tried to learn as much as I could about identifying this highly variable race before and during the winter months so I could discern them among the multitude of Red-tailed Hawks I encountered. I want to thank raptor expert, author, and photographer Jerry Liguori for educating me in my ongoing interest in and study of raptors.  He is the one who turned me on to Harlan's Hawks in the first place when he let me know one of my photos of a Red-tailed Hawk several years ago was more specifically a Harlan's type or race of Red-tailed Hawk. He's conditioned and encouraged me to be more discerning with hawk observations. I'm also grateful to local birders who have increased their awareness of Harlan's Hawks. I see more being reported via eBird and local listservs.

After putting an informal focus on all the Red-tailed Hawks I observed in Utah County during the 2013/14 winter season I am certain that we have many more Harlan's-type Red-tailed Hawks visiting Utah during the winter months. I believe that many Utah birders are identifying a number of Harlan's Hawks as typical "Red-tailed Hawks" or simply "Buteo species" in their eBird reports.

Here's a summary of Harlan's Hawks I observed in Utah County during the 2013/14 wintering season:
  • 13 individual Harlan's Hawks positively identified, some others were possible but not positively identified
  • 11 adults (8 dark, 3 light)
  • 2 juveniles (1 dark, 1 light)
Research indicates most Harlan's Hawks are dark with only about 10-12% being light morphs. My encounters resulted in about 30% (4 out of 13) being light morphs.

Utah winters produce lots of raptors. Unfortunately, the overcast skies and poor lighting experienced during many winter days make it difficult to get quality images. Since this post is primarily about documenting the presence of a species I'm overriding my typical desire to share quality images and including a number of low-quality photos.

Harlan's Number One in Provo, Utah
Adult light-morph showing large amount of white around the eyes, light banding on the belly, mostly banded flight feathers, mostly white and gray tail with some rufous coloring. A local birder, Brenton Reyner, originally located and photographed this bird. I was in the area sometime later and relocated the bird.

Number Two in Lehi (Near Pioneer Crossing Ponds)
Dark adult showing heavy white streaking on chest. The upper side of the tail was mostly dark on this one. Some mottling was visible on the light under tail feathers.

Number Three in American Fork
Light Adult showing prominent white coloring on the upper side. The head showed heavy white streaking and white arc over eyes. Tail was mostly gray/white. I found an adult light-morph Harlan's Hawk in the same field two years earlier. This bird was present only the night I found it. The image was captured from a significant distance after sunset so it has been severely cropped and lightened.  I think this hawk moved on because the field nearby had been cultivated. Cultivating disturbs the habitat preferred by the prey of these hawks, voles and other small mammals.

Number Four in Lehi
Dark Adult with heavy white streaking in the chest along with white streaking in the head. Very little banding in the flight feathers and dark mottling in the under side of the tail feathers. Upper side of tail is mostly dark and rusty with some white/gray. This hawk remained in the area for about a week straight. I saw it off the freeway every day on my way home from work.

Number Five in Lehi
Dark adult with rufous under-tail coverts. I haven't noticed that trait with Harlan's Hawks I'd observed previously. The tail shows a rufous base and tips with a mix of dark, gray, and white. Heavy white streaking in the chest. Mostly banded flight feathers.

Number Six in Lehi
This was a beautiful bird. I was delighted to find this one on New Year's Eve. It was the last bird seen in 2013. It was my first hawk on New Year's Day. It is an adult light-morph with more dark streaking on the underside than I've seen so far on light Harlan's Hawks. The head had contrasting white and dark markings. The tail was mostly white with rufous at the base and a thin dark band at the tips. I saw no banding in the wing or tail feathers. Some light rufous spotting on the under-tail coverts. Slight mottling on the underside of the tail near the tips.

Number Seven at Mill Pond in Lehi

Number Eight
Dark Juvenile south side of Pioneer Crossing and Mill Pond Area. No photos were obtained. This bird was present for only one observation as the sun was setting.

Number Nine
Dark Adult along Spring Creek in Lehi. Tail was a mix of white, gray, and slight rufous coloring.

Number Ten
Dark adult on SR68 north of Elberta. Mostly dark bird with nearly all dark tail. No photos obtained for this one.

Number Eleven
Juvenile Light Morph on SR 77
This bird was severely back lit so I had to lighten the image. The chest and belly of this bird appeared snow white from a distance in the field. The hawk flushed just as I pulled over to capture an image. It had streaking in the head feathers. The marking on the belly was thicker and more contrasting (blotchy rather than streaky) than expected for typical Western Red-tailed Hawks. Barring can be seen extending to the tips of the primary feathers. Barring to the tips on juveniles (not necessarily adults) is indicative of Harlan's. This trait does not apply to adult birds.

Number Twelve
Dark Adult on south side of SR 92. No photos captured.

Number Thirteen
Dark adult found in the same field with Number 5. Both hawks hunted in the same area for weeks. This one had more of a typical looking Red-tailed Hawk tail. It was mostly rufous with thin dark banding, but it also had mottling under the tail and some gray mixed in with the tail. This might be an intergrade of Harlan's and Western Red-tailed Hawk.

Sunday, September 20, 2015

Late-season Hotspot for Small Mountain Owls

I participated in a work conference at Aspen Grove Family Camp and Conference Center this past Thursday and Friday. Aspen Grove is a mountain resort that is owned by the LDS church and is used for family camps, recreation, and a range of conferences. It is located just up the road from Sundance Ski Resort in Utah County, Utah. The conference I was attending allowed for free time Thursday evening after dark so I drove up the Alpine Loop Road from Aspen Grove to where I thought the habitat was right for Flammulated and Saw-whet Owls. I wanted to see if I could locate owls and then show them to my boss and coworkers. I went searching solo at first because I didn't want to drag away a group of non-birders just so they could watch me stand in the dark making strange sounds. I wanted to have some confidence from finding owls before inviting others to join me.  I knew it was getting late in the season for Flammulated Owls because they typically migrate south to Mexico around the end of August and the beginning of September. I thought it would be an interesting test to see if Flammulated Owls were still in the area so I used an app from my phone to produce a Flammulated Owl call. I heard an owl call back to me after a couple of brief attempts with the app. The owl was calling from some aspen trees on the hillside below me. A few minutes later I heard an owl responding from the tree behind me. I moved parallel to the tree while staying on the road to triangulate and pinpoint the location from which the owl was calling. Once I honed in on the right location I put a light on it and found this cool little bird which is about seven inches long from head to tip of tail. For what it's worth the Flammulated Owl is the only small owl in North America with dark irises.

Flammulated Owl in Utah County, UT USA
After finding the Flammulated Owl and hearing a second one I decided to conduct another test. I tried to call out a Northern Saw-whet Owl using my own whistling call.  These owls aren't as vocal or responsive to calling after they've completed their breeding season so this would be another challenge on most occasions this late in the year. Luck was on my side again, however, and I had two Saw-whets responding to my calls within minutes. I used the same triangulation process to pinpoint the location of one owl and then put a light on the spot to reveal this cool little guy. The Northern Saw-whet, about eight inches tall, is my favorite species of owl. I like the following image because it includes both deciduous (an aspen in this case) and conifer trees, the preferred habitat for both Flammulated and Saw-whet owls.

Northern Saw-whet Owl in Utah County, UT USA
Northern Saw-whet Owl in Utah County, UT USA
I believe the following images are of a second owl. The first owl showed a light tip on the upper bill. This one has a solid dark bill all the way to the tip. This Saw-whet flew into and began calling from a nearby tree so I spent a few minutes photographing it as it alternated between watching me and looking in other directions.

Northern Saw-whet Owl in Utah County, UT USA
It is always interesting to watch owls twist their heads so freely. I captured the image below after the owl had turned its head 180 degrees to observe something behind its location.

Northern Saw-whet Owl in Utah County, UT USA
As I was getting back into my truck I heard an owl begin calling from the other side of my truck. This one was at eye level and did not flush as I moved around to the other side of my truck for a very close look. The focused look on the face of the owl below captured the curiosity this bird had in the whistling call I was making.

Northern Saw-whet Owl in Utah County, UT USA
Northern Saw-whet Owl in Utah County, UT USA
After a brief interaction with both species of owl I went back down to the conference center and invited my boss and some coworkers to return to the location with me. I was able to call in and point out a handsome Saw-whet owl for them. They were thrilled to have such a unique experience with a curious little owl. It was fun to hear them puzzle over how I was able to find the owl for them.

Monday, July 27, 2015

A New Generation of Common Nighthawks

Common Nighthawks are quite common throughout the United States and Canada during the spring and summer months. I first became familiar with them when I noticed them flying circles around stadium lights during evening sporting events.  I learned that they were chasing and feeding on the flying insects that were drawn to the lights. They have very tiny bills as you'll see in some of the images below, but their mouths extend back to beneath the eyes. Their "gaping" mouths are great for snatching flying prey. Nighthawks are mostly active at night, but they are sometimes seen flying in daylight, especially during twilight hours. The distinct wing and throat markings of nighthawks are shown in the image below.

Common Nighthawk in Utah County, UT USA

Common Nighthawks have a rather long migration from South America so they tend to arrive here in Utah a little later than other migrant birds. Once they arrive they seem to get right down to the business of breeding. I'm glad that we consistently have breeding populations along some of our local rivers and in pockets of our local deserts. Males and females can often be seen flying together during the breeding season. During courtship the males will make a steep dive and then curve their wings near the bottom of the dive to create a "whoosh" sound as the air rushes through their flight feathers.

Common Nighthawks in Utah County, UT USA

I was showing an out-of-state visitor to some of Utah County's diverse birding habitats several weeks ago when I happened upon a Common Nighthawk nesting site beneath a Juniper tree. We were walking through a desert area that had a mix of sagebrush and junipers.  As I walked toward a particular juniper a female nighthawk flushed from beneath the tree and landed about 15 yards away.

Female Common Nighthawk Distraction Display Near Nest Site in Utah County, UT USA

She began a distraction display which made me realize we were near a nest site. I captured a short video of this particular female to show her protective display. This clip shows the initial display and then ends when she feels she has successfully deterred us from the nest site.

Nighthawks don't actually build nests. They simply lay their eggs on bare ground or gravel rooftops. Consequently, we walked carefully with our eyes to the ground to avoid stepping onto eggs or chicks that might have been blending in with the ground below us. We actually discovered two eggs and then allowed mom to lure us away with her short flights and distraction displays. She was a good mama bird.

Common Nighthawk Eggs in Utah County, UT USA

Common Nighthawk Eggs in Utah County, UT

I am fascinated by the cycle of life so I returned to the nest site a week or so later and concealed my presence with a portable blind. I had hopes of watching the new generation of nighthawks develop from one stage to the next by making periodic visits.  Mama nighthawk was still incubating eggs and did not flush since I remained in my blind.

Female Common Nighthawk Incubating Eggs in Utah County, UT USA

I let another week pass and returned to the site again in the blind. I noticed empty egg shells where mom had been incubating them during my previous visit.

It didn't take more than a few minutes to realize that mom and two chicks were just a few feet away from where the chicks had hatched. Mom moved toward the chicks as I started to back away from the site within my blind.

Female Common Nighthawk in Utah County, UT USA

Common Nighthawk Chicks in Utah County, UT USA

Female Common Nighthawk and Two Chicks in Utah County, UT USA

One chick moved under mom's chest while the other remained visible in the image below.

Female Common Nighthawk With One Chick Beneath and One Chick at Chest in Utah County, UT USA

I couldn't help but wonder how these birds raise their young on bare ground. They blend in rather effectively with their surroundings and mom is adept at distracting possible threats from the young ones, but they are still extremely vulnerable to the coyotes, badgers, rattlesnakes, and other predators that roam the desert floors. I hope these two young chicks progress to the point of making their first round trip flights to South America and back so they can continue the cycle of life by creating their next generation. I wonder if they'll return to the same desert for their own breeding seasons.

My most recent trip to the same general habitat resulted in a close encounter with what appears to be a male with all those bright white throat feathers. The female nighthawk did not show nearly as many white throat feathers.

Common Nighthawk in Utah County, UT USA

Common Nighthawk in Utah County, UT USA