Nature Blog Network

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.

No comments:

Post a Comment