Cooper's Hawk

Our desert neighborhood is full of bird activity right now. Every morning we wake to a cacophony of sound and see darting motion at every window as birds zip past, frantically carrying out their spring time business.  It is not uncommon to see small and mid-sized birds searching the ground for nesting materials and tasty morsels to eat.

What is uncommon is waking up to see a large hawk perched on our small copper reflection pool, surveying the world with beady, yellow eyes. It's also unusual for any bird to hang around for several hours while so much activity is swirling around it, but that is exactly what happened this morning. After capturing some images and admiring this striking visitor, I grabbed my bird book and began the identification process. Mercifully, it stayed long enough for me to take a good, long look.

Judging from the hooked beak and powerful build, this bird is obviously a bird of prey.  It is actually one of the fastest flying birds in the world, known for its great skill in navigating tree tops at high speeds while chasing other birds. It was my first close up look at a Cooper's Hawk, and in this case, a juvenile with mottled brown streaks and prominent yellow eyes. This species of hawk experiences a change of eye color as they mature, from pale yellow and even grey, to orange and blood red.  I am still researching to understand the benefits of eye color changes.

Cooper's Hawks are not compassionate hunters.  They prey on other birds and finish them off by repeatedly squeezing them with their talons.  They have also been known to drown their prey by holding them under water until they stop struggling. During nesting season the smaller male is responsible for meal delivery and is perfectly designed for swift flight and tight maneuvering to accomplish the task.  His smaller, lighter body coupled with long tail feathers allow this stealthy hunter to glide through an obstacle course of tree limbs with great agility.

Nictitating Membrane or Third Eyelid

Like most other birds, Cooper's Hawks have a third eyelid called a Nictitating Membrane.  This semi- transparent membrane slides across the eye horizontally or diagonally and not only helps to lubricate the eyes, but provides protection from wind, dust and rain when the hawk is on the wing... amazing design for sure.

As you track birds this spring, notice the unique design features that make them each successful desert dwellers. If you were a bird of prey, what physical and ability traits would you want to possess?

References and Resources
All About Birds - Cooper's Hawk
All About Birds - Silent Alert
Hawks Aloft Blog
AskAnNaturalist - Sharp Shinned or Cooper's Hawk
eBird - Identifying Cooper's Hawks
Avian Recon - Cooper Hawk Eye Color

Images: Sharon Pegany

Western Screech Owl

This week, we had the pleasure of tracking wonder with British Columbia's wildlife photographer Anthony Bucci. Anthony has an amazing talent for tracking and photographing North America's owls and was recently in the southwest to enjoy some of our local birds and owls.  One owl common to our area is the Western Screech-Owl. True to form, Anthony was able to find this nesting owl and create some amazing photos, giving us a glimpse of the little owl you have probably heard without knowing it.

Western Screech-Owls are small, about the size of a football.  Their feathers are brownish-grey, with lots of variation, which help them blend into their woodland or desert environment. They are nocturnal, coming out to hunt small rodents and insects later in the day and evening.

Adult Western Screech-Owls nest almost exclusively in tree and cactus cavities. They tend to remain in their nesting area year round, so there is a chance to see them even after the spring nesting season. This owl is quite common in the desert so several owls may be living in the same area, defending small nesting territories, but sharing a broader home territory.

Get in the habit of glancing at the holes in saguaro cactus plants.  The holes usually appear dark, but when you notice a lighter colored or blocked hole, take a closer look.  It just might be one of our small owls watching you move past their hangout. Listen for the "bouncing ball" call in which the sounds become closer together like the sound of a ball as it bounces closer and closer to the ground before coming to a stop.  Learn to engage all your senses, letting them pick up on the subtleties that will lead you to pure wonder.

References and Resources
Arizona-Sonora Desert Museum
The Owl Pages
Anthony Bucci Facebook
Anthony Bucci Flickr
Anthony Bucci National Geographic

Image: Sharon Pegany

As a side note, the Western Screech-Owl looks just like the Whiskered Screech-Owl, except for the color of their beaks.  The Western Screech-Owl has a black beak with a tiny bit of ivory on the very tip, whereas the Whiskered Screech-Owl's beak is completely ivory colored. Both can be found in Arizona, although the Whiskered Screech-Owl is not as common.

Cultivate Wonder... Discover Design

e-Bird

Stop what you are doing and go outside.  Close your eyes and concentrate on listening to individual sounds. My guess is that you will hear at least one bird voice in the cacophony of sound. Birds are a part of our everyday auditory experience. The world would be a strangely quiet place without their calls, chirps, whistles and screeches.

Birds amaze us and delight us, but did you know that they play a significant role in understanding ecosystems and environmental health? Birds are critical to the process of pollination, as well as insect and rodent control. Scientists have learned about environmental dangers by observing the changes in bird populations.  For instance, declining populations of bald eagles and peregrine falcons revealed the problem of DDT and heavy metals in the environment.  Coal miners once carried small cages containing canaries to detect the presence of carbon monoxide and other gases.

If you or your child/grandchild have an interest in birds, you may consider starting a free account with ebird.org.  This amazing site/app enables bird trackers world-wide to create sighting lists as well as upload images and sound recordings into a personal account.  The information you provide becomes a part of an enormous database of information that helps scientists and other birders track birds and understand their impact. It is easy and fun to have a place to record your own experiences while also watching your data become a part of something so useful to others.

Using eBird also builds many important life skills. Information provided by bird trackers merges to create interesting charts and maps that can be studied and analyzed to answer your questions.  Challenge children to organize a bird tracking expedition by identifying species, where they are in each season and how to navigate to each location. Critical reading comprehension, data analysis, map and navigational aptitude are just a few of the skills used to plan a trip.  Observation, photography, data collection and report writing are skills used to gather and upload information to the site.

Bird tracking can become a life-long passion and enjoyed no matter where life takes us. Tracking birds often leads to other interests and connects us with a vast community of people all over the globe. If nothing else, it triggers a delicious sense of wonder on a daily basis and keeps us gazing heavenward.

Cultivate Wonder... Discover Design

Resources and References
ebird.org
The Institute for Bird Populations
Desert Birding in Arizona Lessons

Image- Pixabay

Silent Owl Wings

These beautiful birds move on silent wings. Try as we may, it is nearly impossible to hear the sound of an owl coming or going, so they often take us by surprise.

The secret to their stealthy movement lies in the design of their feathers. When air flows over a typical bird wing, turbulence is created, causing a rushing sound. Most bird feathers are stiff and rigid with almost pointy edges.  When air hits them, turbulence is created, causing sound.

Owl wing feathers have several ingenious designs that greatly reduce sound, especially when the wing tilts as the owl nears its prey. The leading edge of the owl's wing is covered with tiny comb-like structures that break up the incoming air into many micro pockets of turbulence. Those smaller gusts of air then flow over the owl's wing to the trailing edge which is made up of a soft fringe and separates or muffles sound even further.  Any remaining sound is absorbed by the downy feathers on the owl's legs and wings.

Owl wings are also larger and wider than the wings of most birds of prey, which gives them more lift so they don't have to flap as often.  Their large wings make them slower, but the combination of size and unique feather features create the perfect design for the nocturnal owl.

Check out these amazing videos which demonstrate the silence of owl flight when compared to other birds.
BBC - Super Powered Owls
KQED - See What Makes Owls So Quiet and So Deadly

Reference and Resources
Ask Nature

Nature

Image - Public Domain Pictures

Harris Hawk

Tonight was a beauty.  The sky was streaked with pastel pinks, purples and sapphire blues.  As I made my way out to owl rock, I noticed the movement of a large bird lifting dramatically over an area of granite boulders. I was able to catch the flash of a white stripe on the tail and quickened my pace, hoping to get closer look.  To my amazement, I not only met the bird, but also his handlers, as well as another bird. They were traveling in a small group and had harnesses and poles on which the birds could perch.

These two Harris Hawks have damaged wings and can't be returned to the wild.  I thought of the sight of a free hawk, soaring high in the sky, and I felt a pang of sadness. Of all animals, birds seem to have the most freedom, so when that freedom is lost, it is even more tragic.

Harris hawks are common in the southwest deserts, but engage in an uncommon practice called "back-standing." Three or four birds can be seen stacked up on one another like circus performers trying to impress a crowd.  By standing on top of one another, the bird at the top may be able to see farther and spot prey.  It could also provide shade. Only the hawks know the purpose, leaving us to speculate and wonder... another design mystery.

Spotting harris hawks in the Sonoran Desert is relatively easy.  Unlike most hawks, they are social birds, so they can be seen in small groups, protecting nesting areas or hunting together.  They are dark brown with rusty red and white markings.  Their long legs are yellow and they also have yellow on their faces.  You may hear their loud, harsh call before you see them, but follow the sound and you may be treated to a back-standing session or a playful game of leapfrog as they fly from rock to rock.

References and Resources
Desert Museum 
All About Birds
Bird Sounds - Harris Hawk

Image: Public Domain Pictures and Sharon Pegany

The Owls Are Back

The great horned owl is the largest owl in the Sonoran Desert,
reaching a height of 2 feet and a tip to tip wingspan of 4-5 feet.

In the Sonoran Desert, our November evenings are nearly perfect for enjoying the night air and observing some of our nocturnal neighbors.  For several nights, we have heard the unmistakable scratch of talons on our chimney, followed by the throaty hoot of the Great Horned Owl. One loud series of hoots is usually followed by a distant call of another owl answering back. We sneak out our back door to catch a glimpse of these magnificent raptors and to listen to their cryptic conversations filling the night air.

November is the time when male great horned owls begin setting up territories in preparation for breeding and nesting. Their calls may be warnings to other owls that they may be in claimed territory. Most great horned owls mate for life, and starting in October, the pair begin their rituals of courtship which include passionate calls back and forth. Adults also make other sounds including whistles, shrieks, barks, coos, hisses and can loudly snap their bills if defending young.

Tonight, open your windows and tune your ears to hear this distinctly autumn sound.  If you live on the edges of wilderness, the owls are probably there.

To hear recorded sounds of the great horned owl:
All About Birds - Owl Sounds

References and Resources
Desert Museum
Nature Blog

Image: Public Domain Pictures