Several people have wondered about Sandhill Cranes flying at night. Like Whooping Cranes, sandhills typically migrate only during daylight hours, presumably because their soaring flight takes advantage of the rising thermals that the heat of the sun produces. But there are plenty of exceptions. In one notable case when we were radio-tracking whoopers in the 80's on the central flyway, a group of southbound radioed whoopers took off one morning from somewhere in the northern plains and flew all day and straight through the night, landing at Aransas on the Texas coast the next morning. (The airplane that was tracking them lost them in the night because it had to land and refuel.) Those birds had a decent tail wind, maybe sensed that they had good feeding conditions ahead of them, and just kept going, to the surprise of everyone involved in the study. Apparently, with the right conditions and/or the right incentives, birds can break the rules.
Along the Platte in Nebraska in the spring, Sandhill Crane flocks will sometimes feed in the fields all night long rather than return to their river roosts. This seems to be associated with bright moonlit nights or on any night following a day or two of severe weather when they weren't able to get out in the fields to feed. During these nights of feeding, they will readily fly from one field to another in the darkness. Even on moonless nights, the starlight creates enough shine on the water for them to follow rivers and creeks and to spot any small water surface in the wet meadows. Ken Strom Audubon Colorado Boulder ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Sebastian Patti Sent: Monday, September 28, 2009 5:37 PM To: Scott Seltman; [email protected] Subject: [cobirds] Re: Reports of Sandhill Cranes; more, please here's a new twist . . . how 'bout NIGHT migrating cranes . . . I've been on the Cimarron River in Baca County and in adjacent Morton County, Kansas, and have had Sandhills following the river east on moonless nites in October and early November . . . always wondered how these birds can do this . . . [email protected] Sebastian T. Patti (Lincoln Park) Chicago, ILLINOIS 60614-3354 PHONE: 312/603-4416 (o) 773/248-0570 (h) FAX: 312/603-2041 (o) 773/248-0264 (h) ________________________________ From: [email protected] To: [email protected] Subject: [cobirds] Re: Reports of Sandhill Cranes; more, please Date: Mon, 28 Sep 2009 16:28:45 -0500 Tony, et.al.: I would be surprised to see very many Sandhill Cranes migrating under conditions so unfavorable that they are only attaining a ground speed of 34 MPH. Usually either they have a tailwind or they don't migrate at all. The exception sometimes occurs in the spring when the urge to head north [die Zugunruhe] often has cranes fighting headwinds until they tire and give up. I'd say the typical ground speed of Sandhill Cranes over this area of west-central KS would be in the 50-100 MPH range. Occasionally on a warm still day one might see them doing the "thermal climb and glide" strategy where it often takes them quite a while to gain altitude, but even then the glide part involves some serious speed. I once attempted to follow a family of Whooping Cranes that sailed over our yard out in open country, but after 15 miles of driving 70-90 MPH on dirt roads I decided it was too dangerous to continue the chase. Yes, cranes sometimes seem slow and clunky when they're down close to the ground, but when they are at high altitudes they are clickin' off those miles. At least that's what I've observed. And I've seen a few! Scott Seltman 1968 155th Ave. Larned, KS 67550 ----- Original Message ----- From: [email protected]<mailto:[email protected]> To: [email protected]<mailto:[email protected]> ; [email protected]<mailto:[email protected]> Sent: Monday, September 28, 2009 12:18 PM Subject: [cobirds] Re: Reports of Sandhill Cranes; more, please For what it's worth, I thought I would enter the Sandhill Crane discussion. I know I have certainly enjoyed reading the reports of the Sandhill flocks. Regardless of whether the reports are scientifically worthy of reporting, they have no doubt added to my personal enjoyment and knowledge of the birds, which is probably why I and many others are on co-birds in the first place, so I want to say thank you everyone for posting these. Just out of curiosity, I used the reports of the N. Boulder flock spotted at 6:30 and, assuming this could be the same flock spotted in Colorado Springs at 9:00, calculated their flight speed. The two locations are approximately 85 miles apart as the crow flies, or in this case as the cranes fly, spotted 2.5 hours later, gives a flight speed of 34 mph. This is definitely in the correct range (25 - 35 mph) as I have later researched, so very well could indeed be the same flock. Maybe this adds nothing of scientific value, but it is fun to ponder and adds to my knowledge. I know I will now be on the lookout for cranes tonight. Tony Wilk 0A Longmont, CO </html --~--~---------~--~----~------------~-------~--~----~ Colorado Field Ornithologists: http://www.cfo-link.org/ Colorado County Birding: http://www.coloradocountybirding.com/ You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.as/group/cobirds?hl=en -~----------~----~----~----~------~----~------~--~---
