Jim Williams has been watching birds and writing about their antics since before "Gilligan's Island" went into reruns. Join him for his unique insights, his everyday adventures and an open conversation about the birds in your back yard and beyond.

Posts about Bird biology

Western Grebes in courtship behavior

Posted by: Jim Williams Updated: May 26, 2014 - 3:19 PM

Western Grebes nest at Sand Lake National Wildlife Refuge near Aberdeen, South Dakota. They have an elaborate courtship behavior that was in beginning stages when I visited there late last week. Courtship culminates with the pair rising to their feet on the water, and with wings abeat, racing across the water’s surface. The birds touch, bow, and nod to each other as pairs are chosen.  

The Western Grebe colonies most reliable and closest to the Twin Cities that Chanhassen birder Bob Janssen knows of are on Lake Osakis in Todd and Douglas counties, and possibly some of the larger lakes in Kandiyohi County south and east of Willmar. Also worth a look are Lake Waconia in Carver County and Pelican Lake in Wright County.  The status of these colonies change from year to year, he said. Janssen is author of a book on Minnesota bird records, and is working on a book about birds in our state parks.

 
 
 

It was a failure to launch

Posted by: Jim Williams Updated: May 14, 2014 - 10:08 PM

A few days ago I wrote about a strange collection of spiders seen at Crex Meadows near Grantsburg, Wis. Stretched along a 150-yard section of refuge road were thousands and thousands of spiders. They were on a sheet of spider silk that looked not like webbing but more like cloudy plastic wrap for food storage. The largest of the spiders would cover a dime. Most were much smaller.

The question was, what was going on? I had never seen anything like it.

I sent photos to a biologist friend. He sent them to Jim Fitzpatrick at Carpenter Nature Center near Hastings. And Jim sent them to his brother, John Fitzpatrick, who runs the Cornell Lab of Ornithology in New York State. John sent them to Mark Deyrup at the Archbold Biological Station in Venus, Florida.

He provided the answer.

I have to note that two days prior, Val Cunningham, who shares with me the birding columnist duties for the StarTribune, also sent me the answer. She found it the old-fashioned way — Google.

The answer is failed mass ballooning. Here’s what Deyrup wrote:

“This … appears to be the result of a mass ballooning event by a number of different species of spiders. This occasionally happens when weather has not been good for spider dispersal. The spiders run up the nearest tall shrub in the open when the weather is dry and breezy and not too cold. They then release threads that (are intended to) carry them away after the threads get long enough. You can see some spiders doing this in the photos. Each spider leaves a thread wherever it goes as they climb the shrub, and many of the threads that are sent out on the breeze end up back on the starting point, so the amount of silk quickly adds up. Sometimes there are so many spiders ballooning that the spiders landing on a field and shrubs cover everything with a delicate layer of silk.”

Map shows how extensive Snowy Owl visits were

Posted by: Jim Williams Updated: May 12, 2014 - 10:00 PM

As a summary to the extraordinary Snowy Owl winter we enjoyed, here's an eBird © map of owl location and movement between January and March. The map was created by the crew at ProjectSNOWstorm, the owl-tracking effort that included the Minnesota owl known as Ramsey.

The map includes so many data points that the mapping software converted all individual points to colored blocks, the more intense the color, the more sightings in that area. Minneapolis is at the extreme left edge of the map.

There were a lot of owls.

Great Egret images

Posted by: Jim Williams Updated: May 9, 2014 - 3:42 PM

Great Egrets are seen daily in a pasture near our home. The bit of land has a small stream running through it, offering good hunting for the birds, and surprising me when this strictly seasonal flow holds fish. An entire egret is an imposing sight. Close looks at egret parts give emphasis to that. Here are egrets feted, toes well armed, and legs, the latter seemingly wrapped in leather like the steering wheel of an expensive car. And the egret’s hunting weapon, testimony to weapon and skill. The fish is a stickleback, a common, small Minnesota fish.

 

Broad-winged Hawk and frog

Posted by: Jim Williams Updated: May 6, 2014 - 11:28 AM

Broad-winged Hawks eat frogs. This one was delivering take-out captured in our pond. The hawks are nesting a couple of yards down the street. The day this photo was taken we watched the hawk visit and pond and its marshy edges three times. We have chorus frogs, Spring Peepers, Wood Frogs, and Leopard Frogs out there. The meal looks like a Wood Frog.

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