Nature Blog Network

Friday, August 7, 2015

2015.5 Chasing the fox

Millie and Roy are constantly on the lookout for predators. In the summer of 2015, ravens were the most common threats in the early season and a cross-fox was a frequent visitor in June and July.

On July 20, the ducks raised a noisy alarm with one mother duck attacking something in the tall grass. We suspected that the fox had "harvested" a duckling close to the shore in Bog Central.

Millie and Roy signalled Arrow to "Flee and Hide" and came to Bog Central on Tall Alert. They used Running Droop Wing displays to pursue the fox across Bog Central, into the underbrush, and out of their territory.

This is part 5 of Millie and Roy's 2015 nesting chronicle.


2015.5 - Chasing the fox from Christy Yuncker Happ on Vimeo.



Thursday, July 9, 2015

2015.4 First lessons in Arrow's education - Dodging dangers

2015.4 - First lessons in colt education - Dodging dangers

There are many potential predators in the neighborhood, including ravens and foxes, as the Alaska Sandhill Crane family forages and explores.

Arrow, the colt hatched a few weeks ago, is encouraged to be vigilant at all times, to stay close to her protective parents, to "flee and hide" when both parents go off to confront a threat, and to watch studiously when the parents make counter-threat displays.





2015.3 First lessons in Arrow's education - Fitness and Foraging

2015.3 - First lessons in colt education - Fitness and Foraging

As a newly-hatched crane colt, Arrow hops, trundles, bumbles, and stumbles after Millie and Roy who hike all day, round and round the nest pond, setting off for excursions into the woods, and even swimming across small channels of the pond. All of this activity helps build the physical fitness that will be needed for foraging, running, dancing, and flying.

The video below shows Arrow followinfg close after MIllie and Roy and being introduced to tasty morsels of seeds, berries, roots, insect larvae and flying insects, and even strips of vole flesh after Roy has skillfully butchered a vole that he hunted.

Hard foods must be macerated, and this takes grinding in the gizzard. To fill Arrow's gizzard with gravel, Millie and Roy bring her to a parking lot where they all feast on gravel while the wary parents keep watch.
from Christy Yuncker Happ on Vimeo.

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.

Wednesday, May 27, 2015

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.

Wednesday, April 8, 2015

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.


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