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Friday Feathered Fact
Since it is the height of baby season, we will look at these youngsters. While most hawks and owls take 28-37 days for the eggs to incubate, the time to reach independence varies greatly. The tiny Elf Owl can be out hunting on its own within 5-6 weeks of hatching and the Barn Owl fledglings will leave the parents not long after they are able to fly, which is 9-11 weeks of age. For the larger birds like the Great Horned Owl, the young will be able to fly well at about 3 months of age but are reliant on the parents for food until the age of 6-8 months. During this time, the parents will follow their “teenagers” wherever they go to deliver dinner. In contrast (and noted in an earlier post) some young Harris’s Hawks will forego life on their own until the age of two as they remain “at home” to help raise their newly hatched siblings.
The Harris’s Hawk — named after Edward Harris in the early 1800s by his friend, John Audubon — is unique amongst the hawks. Living in the Southwest of the US and all the way south to Argentina, this raptor lives in family groups. The alpha-female, which is about 20% larger than the male, leads the family group in a “pack-like” hunt, taking turns to chase down the prey. As part of their social nature, the young born last year often stay with the family to help care for their new siblings born this year before setting off to start their own family. It is not uncommon to see a family of up to 6 or 7 Harris’s Hawk perched together. These hawks also tend to have a broader nesting season and may attempt laying 2 or even 3 clutches in a year. As a species, they have been known to lay eggs in every month of the year.
A wolf in the fold? In Arizona, there are two raptors that can look remarkably alike. These are the abundant Turkey Vultures that often soar in large flocks (called kettles) and the uncommon Zone-tailed Hawk. When soaring up high, each bird looks like the other, even to the experienced birder. It is believed they also look similar to small prey animals on the ground. The non-threatening vultures are ignored by smaller animals which may be why the Zone-tailed Hawk often soars amongst the harmless vultures, camouflaged within the group. Of course, the hawk could also just be taking advantage of the same helpful updrafts (thermals) that help keep these birds aloft without flapping.
Friday Feathered Fact
Daytime or Nighttime? The general belief is owls are nocturnal where they sleep by day and hunt by night. However, this is not true for many species of owls. Examples of diurnal (daytime active) owls include our Burrowing Owl and the Northern Pygmy-Owl. Most of their activity occurs when the sun is up. For some other birds, there is different type of behavior known by a nifty word: Crepuscular. Derived from Latin meaning “twilight”, this refers to being active in the twilight hours of sunset and sunrise. The Short-eared Owl is well known for being crepuscular (and sometimes diurnal). And, if you really like biological terms, there is the rather rare “cathemeral”. This refers to species with no preference and that are equally active during any time of the 24-hour clock such as in some amphibians and primitive primates.
One of the trademark residents of the Arizona landscape is a horned lizard. There are actually six (6) different species of horned lizards found within the state. Commonly — but mistakenly — known as the “horny toad”, this is a reptile with dry scaly skin which scuttles along the ground; and, quite unlike the amphibious toads, this lizard cannot hop.
This particular species is known as the Greater Short-horned Lizard (Phrynosoma hernandesi). A very good identification clue as to which horned lizard species is saying “Hello” to the mascot, Widget, is by the prominent gap between the horns on the back of this lizard’s head in combination with a single row of large, white, pointy scales along its side.
This Greater Short-horned Lizard is not strictly a desert dweller. Instead, it is found in semi-desert grasslands and up into pine forests on mountains. This lizard is more tolerant of colder weather and is likely to remain still, relying on its camouflage as opposed to running away. Another very unique defense mechanism is to squirt a narrow stream of blood from its eye at a predator up to three feet away. This blood is also slightly noxious or sickening to dogs and coyotes.
The primary food for all horned lizards is ants. These hungry insectivores will often sit alongside an ant trail, resting comfortably while lapping up the ants as they scurry by. When ants are not available, they will readily eat spiders, beetles, and other insects.
Is that a one-legged owl? Nearly all birds routinely perch or stand on just one leg. The “missing” leg is drawn up close to the body, hidden under the feathers. Why do they do this? We receive several calls each month about a “poor one-legged owl” needing rescue as it just stands motionless. Actually, this is a comfortable pose for an owl or hawk. Better yet, it demonstrates the bird is calm and not threatened. Another more important reason for a one-legged pose is to regulate the body temperature in the cold. Rotating the one-legged stance cuts in half the amount of exposure to the cold air/water and also helps warm up that cold foot.
Gray Hawks: Our Wild At Heart team is nearly one week into their Arizona trek and have completed over 60 miles. This week they are hiking past the Patagonia-Sonoita Nature Conservancy. This area is well known for the Gray Hawk which has a spotty breeding area limited to the wooded waterways of the desert Southwest.
This species is found through Mexico and into Central America but barely crosses into the US, crossing the border counties in SE Arizona, SW Texas, and the southern tip of Texas.
Gray Hawks have a slightly unique diet. In contrast to most other hawks in the US that feed on birds and rodents, Gray Hawks hunt primarily lizards. Snakes will also be hunted. However, this hawk will also supplement its diet with the occasional taking of some song birds, small mammals, and large insects.
The call of this hawk is rather distinctive, with a higher-pitched, whining whistle. You can hear that bird’s call below. Just click on the triangle-shaped play button at the buttom left.
Friday Feathered Fact
Great Horned Owls are nesting! These are some of the earliest nesters, laying eggs in January and February. Our first egg rescue was mid-February with the chicks hatching this Mar 02. Owls never build their own nests or even add material to it. Instead, they confiscate nests of other large birds or, simply lay eggs on a flat surface in palm trees, rafters, or ledges. The eggs hatch after 30-35 days. About 4-6 weeks after hatching, the young may fall or move to the ground where the parents follow, feed, and protect them for many more weeks. The young gain skilled flight about 3 months after hatching and the parents continue to feed them until they are at least 6 months old. And, remember, do not trim those palm trees between Feb 01 and Sep 01. These trees are critical nesting spots for several owl and hawk species as well as for many song birds. It is more than just palm leaves that fall to the ground during that trimming.
Owls have excellent vision. But, do they have four eyes? The two species of pygmy-owls found in the US have a unique adaptation. The back of the head shows two large eye-shaped patterns believed to offer it protection from larger predators that may approach from behind. These small owls are daytime hunters, specializing on other small birds. So, while the pygmy-owl is looking ahead for its prey, the “eyes” on the back of its head deters a predator, fooling it into thinking it is being watched. (video by ktbirding.com)
When most of us see an owl in the wild, we are often impressed at how big it appears. As an example, the Great Horned Owl is the largest owl in Arizona and stands over a foot and a half tall. However, what is not widely known is how little most of Arizona’s owls really are. Of the 13 species of owls found in the state, 8 of them stand barely 8-inches tall or less. These little guys are highly adept at hiding which helps explain why they are so infrequently seen. These photos with Chelsea Kane and two of WAH’s birds show the size difference between two adult species: Great Horned Owl and Western Screech-Owl.
Contrary to popular thoughts, most owl species don’t simply “hoot”, if at all. Burrowing Owls have many types of vocalizations used in different situations. Some are for advertising their territory, sounding an alarm or, announcing a warning. The warning call is an awesome imitation of a rattlesnake’s “buzzzz”, which shares burrows with these owls. A predatory mammal going down a dark hole after a little owl will think twice about continuing. Listen to these examples from the great online library of xeno-canto.
Owls have remarkable hearing as well as exceptional abilities at locating its prey in nearly complete darkness. Two physical adaptations make this possible. First, the ear openings are asymmetric, with one slightly higher on the head than the other. This allows the sound waves to reach the eardrums at different times which allows for more accurate triangulation. Second, the feathers on each side of the face form a natural “bowl” (aka, parabolic dish) that collects and directs the sound towards the ear openings. For more information, read the nice textbook “Birds by Night” written by Graham Martin.
The 12 Days of Christmas and Holidays
We thank everyone for making this another very successful year for Wild At Heart. Through your efforts, interest, education and donations we have been able to rescue and rehabilitate hundreds of our desert birds.
Remember too, that as you shop this holiday season, Amazon Smile provides an opportunity to raise funds for Wild At Heart. Just sign up at AmazonSmile, shop and Amazon will donate a portion of your purchases to Wild At Heart. To learn more, visit AmazonSmile http://smile.amazon.com/gp/chpf/about/ref=smi_aas_redirect….
We start our 12 days of Christmas celebration with Roja, our female Red-tailed Hawk. Roja is often referred to as our “Empress” because she carries herself in such a regal manner. Roja loves to be out in public at our educational events.
Roja came to Wild At Heart almost 14 years ago. She was found on the ground with a severe case of trichomoniasis which is a protozoan organism that unfortunately caused permanent damage to Roja’s mouth.
Red-tailed hawks are one of the most common hawks seen in North America and can often be seen here in the desert circling overhead riding the currents of the wind. The Red-tailed Hawk cry is also one of the most familiar sounds of the raptor family. Its cry is often used in movies and television shows.
When asked what Roja might like to ask Santa for, she responded that she would like Santa to tell everyone how thankful she is for all the support given to our mission here at Wild At Heart.
On our second day of celebration, we would like to introduce you to Diega, our female Mexican Spotted Owl. Diega came to Wild At Heart as a young adult in 2009. She was found on the ground with nerve damage to her wing.
Diega is another of our educational birds, and there is no escaping her beautiful large dark eyes as she gently gazes upon you. There are three subspecies of spotted owls and the Mexican Spotted Owl is the smallest in size with the largest of white spots.
We think that Diega’s holiday list would include the hope that all our wonderful supporters enjoy a warm cup of hot chocolate in celebration of the holiday season, and that we try our chocolate Mexican style with a little cinnamon and spice.