Tuesday, October 13, 2020

What's Wrapped Up in a Boreal Owl Pellet?

 

Boreal Owl Pellet
Wasatch County, Utah

Why Pellets?

Well, here's a close up of the Boreal Owl pellet I retrieved after one of the owls in my last post hacked it up, briefly clutched, and then dropped it to the ground. This one-inch (2.54 cm) pellet came from an owl that is between nine and ten inches tall (22-26 cm), depending on whether it was a male (smaller) or a female (larger). 

You may already understand the process, but I want to share with those who may not know how a pellet is formed and why it is expelled. Owls, and many other birds, have two stomachs or chambers that aid in the process of digestion. They swallow prey whole or in chunks, but they cannot digest the fur, feathers, teeth, nails, or bones of the prey. The first chamber essentially liquifies the digestible parts with enzymes and sends the partially digested meal to the second stomach, or gizzard, which breaks down the hard pieces, sends the digestible contents to the intestines, and compresses all the useless stuff into an oval shaped pellet. The owl has to regurgitate the pellet from the gizzard before the next meal so this process of creating and casting pellets typically cycles once each day. Many owls cast their pellets from their daytime roosts so locating pellets below trees, particularly conifers, or cliffs and manmade structures such as barns and silos is one way to discover their roosts. 

When I realized that one of the Boreal Owls I was observing October 3rd was about to hack up a pellet I began capturing a series of images as quickly as I could. The image below shows the owl manipulating the pellet before dropping it to the ground.

This Boreal Owl expelled the pellet, grasped it, held it to its bill before dropping it to the ground.
Uinta Mountains, Wasatch County, Utah

Finding this species of owl, considered rare in Utah, was special. Watching one actually cast a pellet was extra special so I considered the pellet a parting gift to memorialize our time together. Drying it out and inspecting its contents struck me as a great way to learn more about the the diet of the owl. Boreal Owls are perch hunters so they wait for prey to appear and then swoop or drop down to take prey with their talons. Small mammals such as voles, mice, and shrews along with small birds and some insects make up the bulk of their diet.

Let the Inspection Begin

The pellet was set aside for a few days before I got around to unveiling the contents and capturing images with a macro lens. Mounting the camera on a tripod would have yielded crisper images, but handholding seemed to meet the need well enough when I added a flash and diffuser to the mix. I probably should have used a solution to remove all the fur from the bones, but I didn't. I kind of sound lazy with those explanations, but I was just really curious about the contents and my casual approach satisfied that curiosity well enough.

Pellet Quiz Time

The anatomical parts seem to belong to at least two mammals (voles?), because I can see jaws and hard pallets for two mouths.  What rodent do you think is represented in the images? I forgot to use a ruler in this image to show scale, but all of it fit into that one-inch pellet shown at the top of this post. The jaw bones were probably 3/4 inches (1.9 cm) long. What parts can you identify before looking at the illustration I've created in the very last image? Please tell me in the comments if you see more identifiable parts and I'll try to add them to my labeled illustration.

Click on each image for a higher resolution view.





Drum roll! And the answer is (with a little help from my veterinary friend):







Saturday, October 10, 2020

A Series of Boreal Owl Encounters

Boreal Owl in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

Let the Boreal Hunt Begin

Hello, friends and nature lovers! A little over two years ago I presented myself with a "lifer" choice that would either have me driving two-plus hours to the Uinta Mountains in northeastern Utah or three-plus hours to parts of the Colorado Plateau near Moab, Utah.  "Lifer" is how birders and herpers (reptile and amphibian seekers) refer to a species observed for the first time in their lives. I was planning to turn either trip into an overnighter to allow myself lots of time to search for the target species. In the Uintas I would look for my lifer Boreal Owl, a rare species for our state. In the Moab area I would go looking for Eastern Collared Lizards. It was mid-summer so it was kind of a choice between the cooler temps of our remote mountains or the warmer temps of the desert. Reptiles had captured my attention at that time so I chose the desert. I went and had a wonderful time sleeping under the stars and finding and photographing the lizard the following day and shared that experience in a previous post found at this link.

Two weeks ago my wife and I did a trip to Yellowstone National Park. Prior to that trip the two-year-old Boreal Owl itch returned so I decided to scratch it by adding an hour or two of owling to the trip.  I would have loved spending more time owling during our evenings, but it was a trip for "us" so my birding interests were barely on the radar for by non-birding spouse. Limited time required me to be efficient so I studied Google Maps before the trip and paid close attention to habitat and location as we drove into the area.

After some downtime at the hotel on our last night of the trip I received the "okay" to venture into the dark and drove to a dense pine forest with sporadic meadows outside of the National Park. As an FYI, I drove to that location because I had planned to play calls to locate a bird and most national parks prohibit the use of recorded calls to attracts birds. The Proper Use of Playback in Birding by David Sibley provides guidelines for using calls to attract birds.

It was quiet that evening on the road I chose, not a single vehicle drove in my direction. I played a Boreal Owl call for about twenty seconds and then listened and waited for a few minutes. With no evidence of an owl being present I tried the process a couple more times. I did this at several stops without getting any indication of an owl's presence. I used my light to scan the trees around me with no success. I drove to what would be my final stop and was again met with utter silence. I glanced at the time on my phone and became aware that it was time to head back to the hotel. I gave the surrounding trees one last look before getting back into the car and that's when this little creature appeared in my view. It was perched in a tree about forty feet away.

Click on the image(s) to get higher resolution views.

Boreal Owl near West Yellowstone, Montana
September 29, 2020

That little owl, standing about 9-10" tall, depending on whether it was male or female (males being smaller), had come to see who was calling without ever making a sound. It was one of the "silent observers" as I call them. 

It was an amazing experience, for which I was incredibly grateful. I gave a verbal thank-you to the owl before departing. It was my second Boreal Owl ever and the first one that I was able to find on my own.

Boreal Owl Near West Yellowstone, Montana
September 29, 2020

Time to Find a Utah Boreal Owl

The success of my first Boreal hunt propelled me to develop a plan for finding my first one in Utah.  Prior to leaving for Yellowstone I talked with a friend who had encountered a Boreal Owl in a remote location of the Uinta Mountains at the end of August. I wanted to get a description of habitat without knowing the specific location. I don't ask other birders or photographers for specific locations of the rare species they discover for two reasons. First and foremost, it avoids putting them in an awkward position when they are uncomfortable with having to say no. Secondly, I actually enjoy the process of learning and discovering things on my own as much as possible. I find great satisfaction and joy in the process of learning, exploring, and discovering for myself what nature has to offer. Capturing images as a result of that process often provides nice memorials for those experiences so I do try to get quality images when possible.

Preparation

To prepare for my Utah search I reviewed the handful of eBird reports of Boreal Owl sightings in the Uinta Mountains, spoke with a biologist who has some experience with the species and studied range maps, habitat, and recordings of their vocalizations online. Some range maps showed a thin slice of the range passing through the Uinta Mountains and others showed the Boreal Owl range skirting around Utah from the Rocky Mountains in Colorado up to Wyoming, Montana, and Idaho. The Uinta Mountains are considered to be on the fringe of the normal range so it began to feel like I might be searching for a needle in a haystack, but that just made the adventure all the more enticing. For additional intelligence I spoke with a couple of local birders who had recently returned from unsuccessful searches in the Uinta Mountains. They generously provided information regarding the terrain that I would need to traverse in the search I was planning. High clearance, durable all-terrain tires, solid suspension, and 4WD would be required. I heard in my mind, "Don't try this at home, kids!" Neither a sedan nor even a small SUV with highway tires would be well suited for such an endeavor.  The location would not be a good place for a breakdown, nor to simply get stuck in a rut, because much of the area is outside of phone service. With all that information I was ready to begin my search and try to answer my question about how common or rare the species really is in the Uinta Mountains.

Success in the Uintas!

I set out on my first Utah Boreal Owl hunt October 3rd. I made it to my starting point during daylight to explore some of the more remote and risky routes in the area. That was a good thing because I lost Verizon service on my phone and was unable to continue viewing the targeted spots I had marked on a personal Google Map. It didn't take long to realize that the roads were rougher than all previous routes I'd taken for owls in other remote mountain locations. I saw lots of great spots to check, however, as I drove deeper into the area. I decided to turn around at one point because I felt like I was in a small ship being tossed to and fro on a roaring sea as I was bounced and tilted side to side from boulder to rut while advancing at a snail's pace. I had already passed through good habitat and it seemed unnecessary to risk the additional wear and tear on my Tacoma.

I stopped as the sun was setting to enjoy the scenery.  It was deathly silent until a Northern Pygmy Owl called from a distant perch and some Mountain Chickadees came in to check me out as I mimicked the call of the Pygmy-owl.

Darkness increased and signaled the time to begin the real hunt for my first Utah Boreal Owl.  I don't know if I got super lucky or if there are more Boreal Owls than we think, but I was able to find my first one after two stops and within seconds of attempting to call for one.  My heart pumped with excitement as I quickly fired off a few fames to document the encounter. I could not believe that the moment had arrived so early in my search because I had prepared myself to return home without seeing one. To my delight, the bird was accommodating and allowed me to capture better images and a brief recording of one of its vocalizations.


Boreal Owl in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

Boreal Owl in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

Once again, I expressed gratitude to the owl before parting. I could have called it a night early and headed home with a great feeling of achievement, but I was then more curious than ever to see how easy or challenging it would be to find another owl. Little did I know that I would choose to stop in a subsequent location that produced two Boreal Owls. They appeared to be a pair, a smaller one presumed to be the male and a larger one appearing to be the female.

Boreal Owl in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

Boreal Owl in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

These two birds vocalized what struck me as contact calls intended to communicate each other's location. The male issued a soft but high-pitched squeak or hiss and the female responded with a slightly louder "wert" call.  Here is a link to the recording of the  Boreal Owl Pair Calling.  The audio file is stored on my Google Drive so if you have the Google Drive app it will probably play well for you. It may help to turn up your volume when you listen to the recording. And, depending on your device, you be required to download the file to hear the soft calls. 

As I was photographing one of the owls it leaned forward and rotated its head side to side a couple of times before expelling a pellet, which it then grasped and held in a talon.

Boreal Owl Casting a Pellet
Uinta Mountains in Wasatch County, Utah
October 3, 2020

Boreal Owl With a Pellet in the Uinta Mountains in Wasatch County, Utah
October 3, 2020

The owl eventually let the pellet fall to the ground and then I retrieved it before leaving the scene because I wanted to take it home, dry it out, and inspect its contents. I saw it as a way to learn a little bit more about the owl I had observed. I'll publish the results of that inspection in a future post.

Needless to say, I was beyond elated with the surprising results of my first Utah Boreal Owl hunt. It was a Boreal Owl bonanza beyond any expectation. I am incredibly grateful for seeing three owls, recording a calling pair, and watching one of them cast a pellet, which became a parting gift of sorts. 

Thank you for visiting my blog and sticking with me through this long post. I hope you enjoyed it and learned something new. May you have safe and excellent encounters as you venture out into nature.

Jeff

Additional resources to learn more about Boreal Owls:

https://www.allaboutbirds.org/guide/Boreal_Owl

https://www.audubon.org/field-guide/bird/boreal-owl



Saturday, October 3, 2020

Northern Breeders Passing Through: Flammulated Owls in Utah County


Flammulated Owl in Utah County, Utah
October 1, 2020

It's been more than two years since my last post. I got lazy and posted images and short blurbs about my nature encounters on Instagram and Facebook. That approach of sharing is okay, but it feels incomplete. Blogging takes more thought and time, but it also allows me to share more of the experiences behind the images. "The image" is the product of an experience and can memorialize great experiences, but the process of experience is where I personally find value. I enjoy learning and sharing what I learn along with my photos and blogging is, in my humble opinion, a better way to do that. So I'm returning to what I enjoy.  I hope you learn from and enjoy what I share.

If I would have consistently listened to my inner child I would be working in nature. I thought it sounded very dignified to be a herpetologist or ornithologist when I first heard and then tried to pronounce those words as a young teenager. Holding a field guide for reptiles and amphibians or birds fed my appetite for finding and learning about the animals on our planet. I wanted to explore, discover, and learn all I could about animals. Mutual of Omaha's Wild Kingdom was my favorite TV show in the late 1960s and early 70s and I would often pull out pencil and paper, and sometimes crayons, to draw and color birds that I noticed while out playing in the yard or the fields, hills, and forests of Kentucky.

Well, the inner child is still alive and has manifested itself this summer by driving me, pun intended, to our mountains to monitor the presence of Flammulated Owls in Utah County. I can be inside prime breeding habitat for Flammulated Owls, a montane mix of conifer and deciduous trees, with a 20-minute drive up our local canyon. I've enjoyed introducing some new birders and a few photographers to this little-known owl species this summer and fall, but I've also been making a point over the past month to check every few nights to see if I can hear or see one of them because I want to know how late in the season their presence can be confirmed in our local mountains.

Prior to this season, the latest encounter I had with a Flammulated Owl was September 23rd. So far this season I've confirmed their presence as of October 1st. Chances are that the local breeders I observed during the summer, and their young, have left the county and are already on their way to wintering grounds in places like Mexico. The birds I've recently observed are most likely passing through as they migrate south from the upper edges of their breeding range, which extends as far north as the montane forests in southern Alberta, Canada. I'll go out a few more times over the next week or two until I am unable to see one or at least hear the soft toots of one of the migratory stragglers.

Be curious and maintain natural spaces for the other creatures that inhabit our amazing planet.

Flammulated Owl in Utah County, Utah
October 1, 2020

This Flammulated Owl displays the flame-like feathers for which it is named.
Utah County, Utah August 1, 2020

Flammulated Owl in Utah County, Utah
September 5, 2020

Resources for learning more about Flammulated Owls:

https://www.allaboutbirds.org/guide/Flammulated_Owl

https://www.audubon.org/field-guide/bird/flammulated-owl



Wednesday, August 1, 2018

Eastern Collared Lizards: Colorful Little Dinosaurs



Where Are You Going?

Some people think I'm crazy. I'm okay with that. I'm aware that I enjoy doing things few others do. A couple of Fridays ago, for example, up until an hour before I was planning to "go somewhere" to explore, I was still deciding whether I'd make a solo two-hour drive for an overnight adventure into the Uinta Mountains of northeastern Utah to look for rarely-seen Boreal Owls or a three-plus-hour drive to the Colorado Plateau to search for, observe, and photograph the most colorful lizard species of the American southwest. Yep. In the words of some people who know me well I was willing to drive hours and sleep alone in the wild just for the chance to see a bird or a lizard. For me, however, it's much more than that.  It's a chain of learning moments that are born of the process of exploring, discovering, and observing fascinating creatures and natural events that many people will never know. My brief and sometimes extended outings put aside the busyness of life for the opportunity to have my own Lewis and Clark or Huck Finn adventures. Fortunately for me we have endless wild spaces to explore around the land we call Utah. The desert won over the mountains last Friday night so the nocturnal Boreal Owl adventure remains on the list of fun things to do.

The three-hour drive to my planned location passed quickly as I observed and pondered over the varied and impressive geological features formed over countless years between the Wasatch Range of the Rocky Mountains and the Colorado Plateau. I packed a tent for the night, but I eventually decided to sleep under the stars in the bed of my truck. I texted a GPS location to my wife so she'd know where I would be sleeping and then spent some time stargazing with the help of my SkyView phone app. The International Space Station passed overhead. I was impressed by how bright it was and how quickly it was moving across the night sky. Meteors, Mars, and some constellations drew my attention before eventually getting "some" sleep.

The Colorful Little Dinosaurs Revealed

I was up before sunrise and ready to explore so I retrieved my black light to see if a short walk around the surrounding sagebrush habitat would reveal a scorpion or two. This particular image is from a different outing, but I'm sharing it to show how obvious the presence of a scorpion becomes under a black light in the dark. They are nearly impossible to miss under these circumstances.

I arrived at a wash littered with small but ancient boulders shortly after sunrise. The boulders were surrounded by desert sand and sparse vegetation, ideal habitat for collared lizards. Direct sunlight was warming the surface of the rocks, but apparently the seventy-degree temperatures weren't quite warm enough since the first hour of searching proved fruitless. Once the temperatures got into the low eighties, however, brightly-colored Collared Lizards began to appear, almost magically, on to tops of numerous boulders.  I observed the first one from a distance through my binoculars. As the morning went on I was able to learn a few techniques for getting closer observations without causing the lizards to prematurely vacate their rock-top positions for the safety of their hiding places.  Close encounters with lizards often make me feel like I have a link to prehistoric dinosaurs, but during this and other recent hikes to find collared lizards I have actually been fascinated with the thought that the rocks on which I hike and find the lizards literally are older than dinosaurs.

I hope you enjoy this small collection images representing both males and females. I look forward to revisiting the Colorado Plateau to spend more time with this species and one more target species, the Long-nosed Leopard Lizard.

The first two images show the orange/red markings that appear on females during the breeding seasons. These colors fade once the female has deposited her eggs.




This male looked more like the Great Basin Collared Lizards I find closer to home. It has the large head and bolder throat marks of a male, but it lacks the bright colors associated with males.



Here's another female. She lacks the spots and coloring found on the throats of males.


This male has bolder spots on the face and throat, but the green is somewhat moderate compared to other males. I saw some males that appeared to be more blue than green, but I was unable to capture images of them.


I'll wrap up this post with a couple of images of one more male and a few Eastern Collared Lizard facts.




About Eastern Collared Lizards:

  • Snout to vent length of about 4 to 4.5 inches (males larger than females)
  • Total length with tail can reach about 14 inches
  • Diurnal and prey on a variety of insects, spiders, and other lizards, including smaller lizards of their own species
  • Largest range of all collared lizards of the American Southwest, found in central and southwestern US down into Mexico