2015.2 Millie and Roy incubate on the frozen marsh

2015.2 - Incubation month

On May 5, Millie and Roy began incubation on a nest they sited on frozen marshland across the pond. Three days after they started nesting, a pair of intruder cranes landed on the west bog. Millie and Roy summarily and loudly routed the interlopers and chased them into the valley.

The video below shows some events over the 32 days as Millie and Roy rotated incubation shifts. Roy incubated during the day, and Millie usually took the longer night shift.

The eggs are expected to take 30 days to hatch, but this year we saw no colt until June 6, 32 days after incubation had started. We suspect that the 2015 single colt, whom we named "Arrow", was hatched from the second egg.


2015.2 - Alaska Sandhill Cranes nest and incubate on the frozen marsh from Christy Yuncker Happ on Vimeo.

2015.1 Nestwatch 2015 - Millie & Roy return

Since 1996, a sandhill crane pair has returned from migration to a marsh in Goldstream Valley, north of Fairbanks, Alaska.

On April 27, 2015 at 6:15 AM, crane unison calls roused us from a sound slumber. We looked out our living room window to see "Millie" and "Roy" calling boisterously from the cranberry bog. After cautiously exploring the territory for 13 minutes, they flew across the valley to a secondary auxilary pond. That afternoon they came back to inspect, to dance, to snooze standing in meltwater pools, and to copulate. In the evening, they took wing to a roost across the valley.




 

Christy first recorded a copulation in 1999. A crane-fox standoff occurred on the following day, suggesting that the cranes had established a nest territory. In 2001, a fox chased a crane off the nest. From that time on, Christy has kept a log documenting crane arrivals and daily activities until their departure on migration in September. Since 2001, we have referred to these two cranes as Millie and Roy.

We suggest that the cranes who have summered on our cranberry bog for the past many years might be the same individuals, returning  again and again.  Sandhill cranes do live 25-40 years. Thousands of close-up photos (since 2004), hundreds of videos (since 2009), and daily journal entries on behaviors (since 1996) are consistent with our suspicion that the same individual birds are coming back to nest, year after year.

By careful sonography of unison calls and other vocalizations, Dr. Bernard Wessling can reliably identify individual Common Cranes and Whooping Cranes. After analyses of unison calls recorded from our cranes in 2008 and 2012, Dr. Wessling concluded that the unison calls from both years are produced by the same individuals.

Eurasian Crane Displays - Trandans & Tranbeteende

Carl Christian Tofte and Jessica Lee Hjort have created a fascinating and altogether lovely guide to the behaviors of Eurasian Cranes on their staging grounds near Pulken, Sweden.

This is an important resource for crane behavioral biologists.

Carl Christian's meticulous and stunning artistry depicts individual postures in the Eurasian Crane dances, See http://grusgrus.tofte-hjort.com/ and look at all the links across the drop-down menu, especially those used in their behavior guide entitled "Trandans & Tranbeteende"
(http://grusgrus.tofte-hjort.com/dans-beteende/introduktion/) and Carl Christian's book (Tranedans) which has been published by Koustrup & Co (www.koustrupco.dk).

Carl and Jessica have provided videos of the cranes interacting on the staging area. See http://grusgrus.tofte-hjort.com/video/videoklipp-1-5/.

Finally, one should follow read Carl Christian's blog http://carlchristiantofte.blogspot.com/.
On April 6, 2015 he was still seeing over 6000 cranes in Pulken.

For handicapped folks like me, whose speak only one language, Google provides approximate translations.

After study at the Danish Design School of the Danish Royal Academy of Arts (afgang 2000), Carl Christian established himself as a skilled wildlife artist. Among his many projects are the illustrations in books on Scandinavian and Bolivian birds.

Jessica holds a BFA from Central St. Martins School of Art & Design in London and an MFA from Konstfack in Stockholm.

TRANDANS & BETEENDE | Guide til den eurasiska tranans dans & beteende

VÄLKOMMEN Välkommen till vår websida om Trandans & tranbeteende! Sekvens med hopp och bugning-resning. Illustration från “Trandans” (Koustrup & Co)Detta...

grusgrus.tofte-hjort.com

Millie and Roy, back again in 2014

To see a vortex of migrating cranes in western Nebraska, go to

Sandhill Crane Vortex from Christy Yuncker Happ on Vimeo.


Millie and Roy returned on May 4th and began incubation on May 12th, but the eggs did not hatch. They foraged and danced often during the summer (see video below) and then departed on migration on August 29th.

The Early Life of Pi

For the Early Life of Pi, go to Pi's homepage.

A pair of sandhill cranes, who we know as Millie and Roy, has nested on our property for over a decade. Christy Yuncker Happ has watched, kept a written journal, and photographed Millie, Roy, and their colts through every day of 10 nesting seasons. They hatched 11 colts and fledged 7.

In 2013, Millie and Roy returned from migration to a snowy pond on May 8^th. They began incubation on  May 18^th.

Pi hatched on June 16^th, fledged on August 8^th, and migrated with Millie and Roy on September 8^th.  Over 13 weeks, Millie and Roy coached Pi to dance, to run and wing-flap in pre-flight training,  and to learn the social cues for flying in tandem.

Pi's progress as he foraged and learned to dance and fly is described in 15 gallery-segments of stills and videos. To view the Table of Contents, click on the image below.

Is crane dance innate or learned?

Crane dance is iconic. All 15 species of crane communicate with elaborate body language¹. Comparisons among species reveals clear and consistent distinctions.

Do species differences in dance prove crane displays are innate?         We think the question is inappropriate and based on a false dichotomy.

Animal behavior was validated as "real science" when the 1973 Nobel prize in Physiology went to Karl von Frisch, Konrad Lorenz, and Nikolaas Tinbergen.

At the time of that 1973 prize, neurophysiology was limited to electrophysiology of individual nerve cells and included little more than hand-waving at the psychological realm that emphasized learning, emotion and mental processes. 

The research of these 1973 Nobelists was solidly grounded in precise observation of a defined set of behaviors, with a perspective that dodged between the sentimentality of anthromorphism and the formal dogmas of behaviorist psychology rampant in their day. The scientific rigor of these ethologists first bought a measure of scientific respect to biological study of behavior. To encourage a thorough examination of a behavior, Tinbergen² suggested that each behavior should be explained according to:

• Function (adaptation)
• Phylogeny (evolution)
• Causation (mechanism), and
• Development (ontogeny. 

None-the-less, ethology also had its own dogmas -  for example, that animal behavior is composed of "fixed action patterns" that are expressed when genetically-defined "sign stimuli" act on an "innate releasing mechanism". 

What physiological mechanisms underlie the fixed-action-pattern concepts? In his early writings, Lorenz attempted to explain behavior by analogy with a hydraulic model which is engagingly depicted in the animated gif borrowed from flyfishingdevon.co.uk.  Tinbergen used an electrical circuit model.

Neither analogy was readily transferable to flesh and blood.

The scientific approach to the songs of birds emerged at the same time as the birth of ethology, but "birdsong science" avoided tortured mechanistic analogies. Instead, research on birdsong focused on physiological linkages between behavior observations in the wild and experimental neuroscience in the laboratory.

Songs of nightingales, canaries, and other birds had delighted esthetes and challenged scientists since the Renaissance.

Birdsong research became tractable due largely to the use of the sound spectrograph, a device  invented in World War II for underwater eavesdropping on enemy submarines. In pioneering laboratory and field investigations, William Thorpe, Peter Marler and many others (see Nature's Music³) recorded and dissected the songs of birds and meticulously cataloged the species-specific differences.

Birders (and birds themselves) can readily identify each bird species by its unique song. Does it necessarily follow that bird songs are innate?

A pertinent response to this question is the "learning curve" as young male songbirds become able to sing like their fathers.  As Marler notes, one conclusion is inescapable from the research results:

"when we adopt a developmental approach, which is what Tinbergen was advocating, the instinctive/learned distinction loses its logical underpinnings."²

Since the mid-20^th century, there has been a torrent of scientific papers on the progressive changes as young birds acquire adult song and on the roles of the various brain centers that preside over singing.

"Practice makes perfect."

Birdsong vocal learning is now an attractive general model for research on the cellular basis of motor learning. One example of motor learning is a high school athlete becoming proficient at pitching a curve ball. The rough draft of the "throwing" behavior is already present in our brain and is perhaps innate.  But training and practice profoundly refines that rough draft.

For songbirds, young males acquire their song "target image" by listening to a model tutor, usually their father. Then, weeks later, the young birds begin to sing an adult tune on their own as they acquire an ability to duplicate the memorized song of the tutor. As they practice, birds embellish and perfect an innate capacity.

The brain centers and nerve networks

In the last few decades, laboratory scientists have identified the brain centers and networks responsible for birdsong and vocal learning.

The neurocircuit diagram (right), adapted from one published by Michael Brainard's lab at the University of California-San Francisco, offers a reconstructed layout of birdsong pathways⁵ in the brain. The centers are:

1. posterior centers (HVC, RA...) that drive motor neurons of the syrinx [shown in black],
2. anterior centers (Area X, LMAN....) required for song learning [shown in gray & red],
3. centers that motivate a bird to sing [circled in pink], and
4. sensory centers [not shown] that monitor each song emitted and thus allow comparisons of output with other songs held in memory.

Now in the 21^st century, research of many labs is directed toward exposing the physiological and molecular bases for song variability and individual specificity. Birdsong has become an important biomedical model for probing the cellular bases of learning. We will discuss the centers in more detial in future Blogposts.

As birdsong science took off, the underlying neuroscience of bird brains experienced a revival due to results from molecular embryology. The neuro-geographical map of bird brains was re-interpreted and revolutionized in the last decade (Reiner et al., 2004⁶ and Jarvis et al., 2005⁷  and discussed in our earlier Blogpost).

Birdsong and crane dance

Walking, flight, and birdsong improve with practice, as does the acquisition of dance skills by young Sandhill Cranes (known as colts). Very young crane colts display to each other and interact with their parents, starting in the first few days after hatching.  Over the ensuing weeks, the parents "encourage" the colts to dance, as shown in the image below when the colt was 21 days old.

In the weeks following, the  colt flail-dances with the father parent at 35 days of age (below left below) and dances smoothly with parents by 40 days later (below right).

Sandhill crane displays are complex. Some of the dance lexicon is depicted in print¹ and on the web and progressive acquisition of dance skills is generally summarized on a related page.

The table outlines intriguing behavioral parallels between the acquisition of adult song in young male zebra finches and acquisition of dance displays in young cranes.

For finches, the neuroscience/brain center correlates of the behavior are under intensive study in several major research laboratories. There is yet no data on the brain centers that preside over dance in cranes.  However, the acquisition of crane dance behavior is strongly suggestive of motor learning and that is underlain by brain circuits like those for birdsong.

Crane dances are refined over many years. Dance performance probably improves over the 2-3 years while young cranes dance in crowds to assess potential mates. Furthermore, we have a photographic chronicle that demonstrates marked shifts in the selection of postures and the execution of displays for the dances between the male and the female of a pair that we have watched on their nest territory for over a decade.

As Peter Marler noted (quoted above), the instinctive/learned dichotomy for birdsong disappeared when scientists in the 1970's used a developmental approach. Our developmental approach to crane dance appears to yields the same conclusion: dance is not wholly innate or wholly learned.

Dance reflects motor learning as the bird refines and develops genetically based capabilities. For dancing of cranes as for vocal learning of songbirds, motor learning optimizes better communication among members of a species.

Birdsong and vocal learning are generally thought to have evolved independently in three avian lineages: oscines (higher passerines), hummingbirds, and parrots. In an important study, Erich Jarvis' lab at Duke University and his German colleagues have shown that brain centers for birdsong are akin to brain motor centers, like those concerned with walking and flying.⁸ The ontogeny of dance in cranes may well reflect the presence of motor learning in a fourth avian lineage.

Finches progressively refine and improve their songs by comparing with a memory of their tutor's song which they heard during a sensitive period in their young lives. Whether cranes use memories of their parents or the responses of dance partners (or both) remains to be investigated.  It may be that crane motor learning is lifelong, unlike songbird vocal learning where sensitivity to the tutor is restricted to a particular period in a young bird's life.


References-
1. DH Ellis, SR Swengel, GE Archibald & CB Kepler, 1988. A sociogram for cranes of the world. Behavioral Processes 43:125-151
2. N Tinbergen, 1963. On aims and methods in ethology Zeitschrift fur Tierpsychologie 20:410-433.
3. P Marler & H Slabberkoorn, 2004. Nature's Music - The Science of Birdsong  Elsevier 
4. P Marler, 2004.  Chapter 1: Science and birdsong: the good old days, pp 1-38 in Nature's Music.
5. TL Warren, EC Turner, JD Chaerlesworth & MS Brainard, 2011. Mechanisms and time course of vocal learning and consolidation in the adult songbird. J Neurophysiol 106: 1806-1821.
6. ED Jarvis, O Güntürkün, (25 other authors) A Reiner & AB Butler, 2005. Avian brains and a new understanding of vertebrate brain evolution. Nature Neuroscience 6:151-159.
7. A Reiner A, (27 colleagues), Jarvis ED, 2004. Revised nomenclature for avian telencephalon and some related brainstem nuclei. J Comp Neurol 473:377-414.
8. G Feenders, M Liedvogel, M Rivas, M Zapka, H Horita, E Hara, K Wada, H Mouritsen & ED Jarvis, 2008. Molecular mapping of movement-associated areas in the avian brain: a motor theory for vocal learning origin. PLoS ONE 3: e1768, DOI 10.1371/journal.pone.0001768

Best books - Sandhill Cranes in the Great Plains and elsewhere

BOOK REVIEW:  
Sandhill and Whooping Cranes: Ancient Voices over America's Wetlands by Paul A. Johnsgard. Bison Books of the University of Nebraska Press [published 2011] and

On Ancient Wings: the Sandhill Cranes of North America by Michael Forsberg [published 2004]

The spring staging of Sandhill Cranes in the shallows of the Platte River in Nebraska ranks among the great mass migratory events on the globe.

Paul Johnsgard provides an overview of the status for Sandhill and Whooping Cranes that updates his classic Crane Music [1991].
The prose is consistently graceful and the illustrations both meticulously accurate and artistically delightful. The first three chapters of this book are status reports on "Lesser Sandhills", "The Other Sandhills", and "Whooping Cranes". Each blends history and biology, spiced with personal observations. Paul imbues the descriptions with awe and respect for these magnificent birds.

Lesser Sandhill Cranes endured the depredations of 19th century market and sport hunting and now the Platte collects 400,000 to 500,000 birds every March. Nonetheless, these cranes are still under some threat, from hunting pressure during the winter in Texas, from atrophy of the Platte due to agricultural irrigation, and from competition for food from thousands of resident Canada Geese and millions of migratory Snow Geese that arrive in Nebraska a few weeks earlier.

The mid-continent crane populations have a hourglass-shaped migration pattern. In late February and March, they converge on the Platte from wintering sites spread from western New Mexico and northern Mexico to the Gulf Coast of Texas. Once in the spring fueling mode in Nebraska, the cranes spend weeks of day-times converting waste corn from the surrounding fields into fat to store for the second major leg of their migration. Every night, they return to dodge the powerlines and touch down in cacophonous cascades until they can roost, huddled in swirling transient clusters in the shallows of the river.

On a warm March day with rising thermals, groups of birds spiral gently upward and splay out to the north, finally ending their journeys at higher latitudes from Hudson Bay to Siberia.  As they near their traditional nesting territories, ponds and marshes are still icy. Within 3-4 months, the crane colts are fledged and as temperatures dip below freezing again and families start a long more leisurely journey south.

The Other Sandhills are a collection of populations or races that are rather like clans of nomadic people.  The birds differ somewhat in size (weight, wing-spread, bill-length, etc.) but are mostly distinguished by migration geography.  Some (technically Lessers) migrate from nesting grounds in southwest Alaska to California, others (technically Greaters) from Idaho to New Mexico or (the Great Lakes population) from Michigan to Florida.  These migratory patterns probably reflect the distinct cultures of each population that are passed year-by-year from experienced birds to younger ones as they travel together.

Some Other Sandhill populations (subspecies?) are non-migratory. The resident cranes in Florida grasslands, suburbs, and shopping centers overlap with migrants from Michigan in winter months. The more remote groups in Mississippi and Cuba remain threatened and isolated. A tiny population of these long-lived birds has persisted for many decades on a National Wildlife Refuge in Mississippi, often with yearly infusions of new colts hatched in captivity.

The stature and majesty of Whooping Cranes and their plumage captivates almost everyone who sees them. During the early years of the 20^th century, pressure from the millinery markets of sophisticates decimated their populations. In 1937, the establishment of the Port Aransas National Wildlife Refuge on the Gulf coast of Texas preserved a dedicated wintering ground, albeit precariously close to heavy commercial barge traffic on an intercoastal waterway.  Occasional illegal harvesting persisted, but somehow numbers held steady at a few dozen adults until the remote nesting ground for the Port Aransas flock was discovered in Canada twenty years later. Conservation efforts in Texas and Alberta and appeals to reduce hunting have paid off such that 263 cranes started from Texas on their journey toward Canada in 2010, along the path depicted in Johnsgard's map to the left. Continued vigilance and monitoring of the individual birds each year must remain a high priority.

Many well-publicized efforts have been devoted to establishing other Whooping Crane populations.  These include a failed attempt to cross-foster Whoopers with Sandhill parents in Idaho that started well but faltered, and a multi-year struggle, that was ultimately abandoned, to create a resident population in Florida.  As of 2009, the 22 surviving Whooping Cranes from this flock are being protected and monitored.

Still ongoing is Operation Migration, an entrancing project of a non-profit corporation working with the International Crane Foundation and the USGS in Patuxent (MD). Operation Migration nurtures hatchlings chicks at the ICF in Wisconsin and then teaches the young colts to migrate in the fall by following an ultralight airplane to Florida and returning in the spring, led by the ultralight back to Wisconsin. This flashy project seems to be working as some of the the returning Whooping Cranes are making nests in Wisconsin. The next critical landmarks are sustained nesting in the wild, fledging of significant numbers of colts, and independent migration (without an ultralight leader) to Florida.

Very recently, there is a new attempt to establish another resident population, this time in Louisiana. It will be many decades before we will know if any of these investments yield self-sustaining populations.

Like Sandhills, Texas Whooping Cranes migrate through Kansas, Nebraska, and the Dakotas, but they travel in small groups in the late spring.  Cranes are particularly vulnerable during these long migrations. The impacts of changing fashions in agricultural economics, pressure for increased biofuel production, and drought cycles which may be exacerbated by global climate change, are some of the factors that menace crane stopover sites, of which the most important is the Platte River valley.

The Appendix of Johnsgard's s slim, information-packed volume tells the reader exactly when and where to find cranes in 34 states and provinces of the US and Canada. It is very helpful to have one list of these unheralded habitats where cranes can be observed by carefully scheduling a visit.

Mike Forsberg may be best-known for his stunning images of fauna, flora, and scenery of the Great Plains. He is a keen observer and careful student of natural history, an avid conservationist, and a lucid writer. On Ancient Wings grew from several years of watching and photographing different populations of cranes.

On Ancient Wings is a series of vignettes of cranes in the wild, as Mike traveled from Alaska to Mexico, across to Florida and down to Cuba.

The informative text is enhanced by Mike's striking photographs of the cranes, their behavior, the neighboring animals and plants, and the landscapes. The images almost overpower the narrative that likewise deserves very careful study.  Mike introduces the reader to the local culture and the people who study and protect the cranes. Each crane population is unique and Mike's journal entries provide great local flavor.

Although Mike Forsberg started as a still photographer, more recently he has become skilled with video as well. His talent was showcased a few years ago in a NET (Nebraska Educational Television) video production for On Ancient Wings. 

For a lyrical introduction to Mike's skills, view the recent Flash video promoting his upcoming NET production on the Great Plains - America's lingering wild  or visit his exhibition in April 2011 at the National Museum of Wildlife Art in Great Falls, Montana.

Great Plains promo - NET Nebraska and Michael Forsberg from Michael FORSBERG on Vimeo.

Johnsgard's Sandhill and Whooping Cranes and Forsberg's On Ancient Wings very nicely complement one another. Both have a mix of the big picture and specificity, and each offers an informed original perspective on cranes and their biologies. Royalties from these books go to the Rowe Audubon Sanctuary, a craniac's mecca a few miles east of Kearney, Nebraska.