"A Miocene crane fossil, thought to be about ten million years old, was found in Nebraska and is structurally identical to the modern Sandhill crane, making it the oldest known bird species still surviving!" International Crane Foundation
Sandhill cranes are sometimes referred to as "living fossils", but I'm not sure whether they received that label because of their pre-historic ancestors, or because of the primordial quality of their trilling calls as thousands of cranes gather to rest and feed in a wetland staging area.
Long held as symbols of longevity and prosperity in many cultures, cranes mate for life, and sandhill cranes may live as long as 20 years in the wild. Add to these qualities, their ballerina-style grace, spreading wings like parachutes with trailing legs as they float to a landing, and you have a heart-grabbing, charismatic species. Watching the sky as sandhill cranes approach in the pale morning light is a moment guaranteed to wrap you in utter awe and silence.And looking through these images is taking me there again and again, and bringing into focus things I haven't noticed before. One special enjoyment I've encountered--so many sandhill crane faces! They're all different! I've also noticed many variations in juvenile skin patches, as well as, what appears to be black fuzz on many of the red patches we refer to as "bald" skin. So I consulted several of my biologists friends for answers, among them, George Happ and Christy Yuncker, authors of the Sandhill Crane Display Dictionary. And I learned some fun new information.
Juvenile sandhill crane, above. The light shows the fine black bristles on the youngster's skin patch. Notice the cinnamon feathers on the back of the head and neck.
We experience a special treat while sandhill crane viewing in Tennessee. While those who are privileged to have sandhill cranes during breeding season observe nesting behavior and the raising of young colts, we, who see them during migration on their staging and wintering grounds, get to see the in-between stages as the juveniles gradually change to gray plumage and develop the red skin patch that is characteristic of mature adults. By the time they return to their breeding grounds in the spring, most of this season's young will look just like their parents, even though it will be an average of four more years before they produce off-spring.
What we typically call a bare red skin patch, is not really bald at all, but sparsely covered in fine black bristles, as shown in the adult sandhill crane, above.
You can also see that the juvenile skin patches are in various stages of maturity. Some of them only have red skin around the eyes and brow, others have a more extensive patch but still show many gray feathers where the red skin will eventually appear. My guess is this variation in skin patch development may be, at least in part, an indicator of the age of the juvenile, how early or late the juvenile hatched in the season.The juvenile above has a red-skin patch developed around his eyes and brow but the forehead and crown are still covered in gray feathers. Below, you see two juveniles having a territorial dispute. In the first image, you can see one adult on the left in the background focused on a crane hidden from view. In the second, you can see the two adult sandhill cranes bill-sparring on the left, as one juvenile chases the other away.
To hear a typical sandhill crane voice click here. After you have heard this sound, imagine a crane near the same size with the peeping voice of a chick. I heard one of these peeping calls as I was observing and I think it may have belonged to the youngster you see here. You can also hear these calls while cranes are flying overhead, juveniles calling to their parents in the same manner that older cranes are vocalizing.
This juvenile has lots of gray feathers covering his crown. There is only the faintest appearance of red skin forming near the eyebrow. And for size comparison, below you see him with an adult, likely a parent.
I believe I could spend days on end observing and learning about these birds.
Links and Resources:
To see my entire Hiwassee Sandhill Cranes series click here.
For more information about the Sandhill Crane Display Dictionary
Top Crane Posts on this blog: Hooded Crane at the Hiwassee Wildlife Refuge in TN
Crane Magic--Three Crane Species at Hiwassee. Other posts on: the Tennessee Sandhill Crane Festival, Hiwassee Wildlife Refuge and sandhill cranes.
Sandhill crane art in my website galleries